Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Demand-side decarbonization and electrification: EMF 35 JMIP study

Demand-side decarbonization and electrification: EMF 35 JMIP study Japan’s long-term strategy submitted to the United Nations Framework Convention on Climate Change emphasizes the importance of improving the electrification rates to reducing GHG emissions. Using the five models participating in Energy Modeling Forum 35 Japan Model Intercomparison project (JMIP), we focused on the demand-side decarbonization and analyzed the final energy composition required to achieve 80% reductions in GHGs by 2050 in Japan. The model results show that the electricity share in final energy use (electrification rate) needs to reach 37–66% in 2050 (26% in 2010) to achieve the emissions reduction of 80%. The electrification rate increases mainly due to switching from fossil fuel end-use technologies (i.e. oil water heater, oil stove and combustion-engine vehicles) to electricity end-use technologies (i.e. heat pump water heater and electric vehicles). The electricity consumption in 2050 other than AIM/Hub ranged between 840 and 1260 TWh (AIM/Hub: 1950TWh), which is comparable to the level seen in the last 10 years (950–1035 TWh). The pace at which electrification rate must be increased is a challenge. The model results suggest to increase the electrification pace to 0.46–1.58%/yr from 2030 to 2050. Neither the past electrification pace (0.30%/year from 1990 to 2010) nor the outlook of the Ministry of Economy, Trade and Industry (0.15%/year from 2010 to 2030) is enough to reach the suggested electrifica- tion rates in 2050. Therefore, more concrete measures to accelerate dissemination of electricity end-use technologies across all sectors need to be established. Keywords Demand-side decarbonization · Electrification · Multi-model scenario analysis Introduction Background Under the Paris Agreement, Japan pledged to reduce its greenhouse gas (GHG) emissions by 26% by 2030 from the Handled by Kenichi Wada, Research Institute of Innovative Technology for the Earth, Japan. * Shogo Sakamoto National Institute for Environmental Studies, 16-2 Onogawa, sakshogo@criepi.denken.or.jp Tsukuba, Ibaraki 305-8506, Japan Institute of Applied Energy, 1-14-2 Nishi-Shimbashi, Minato, Environmental Science Research Laboratory, Central Tokyo 105-0003, Japan Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba 270-1194, Japan School of Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan Socio-Economic Research Center, Central Research Institute of Electric Power Industry, 1-6-1 Otemachi, Chiyoda-ku, Institute of Energy Economics, Kachidoki 1-chome, Tokyo 100-8126, Japan Chuo-ku, Tokyo 104-0054, Japan 3 9 Institute for Future Initiatives, The University of Tokyo, Institute for Global Environmental Strategies (IGES), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan 2108-11 Kamiyamaguchi, Hayama, Kanagawa 240-0115, Japan Graduate School of Engineering, Kyoto University, Kyoto daigaku-katsura, Nishikyo-ku, Kyoto 615-8530, Japan Vol.:(0123456789) 1 3 396 Sustainability Science (2021) 16:395–410 2013 levels and cut emissions by 80% by 2050 (Government Research questions and aims of Japan 2019). As of 2018, the GHG emissions stood at 1240 Mt-CO2e, and around 50% were direct emissions from As mentioned above, while Japan’s Nationally Deter- the demand-side (Industry 25%, Residential 5%, Commer- mined Contribution (NDC) proposes an increasing share cial 5%, and Transportation 18%) (Ministry of the Environ- of electricity in 2030, Japan’s mid-century strategy lacks ment 2020). a concrete level of electrification. The low-carbon vision The power sector is going through a major reform in from the Ministry of Environment and Japan’s long-term Japan, and a rapid deployment of renewable energy has been strategy also do not reveal quantitative electrification path- contributing to supply-side decarbonization. In parallel with ways through 2050. Therefore; this study examines 2050 supply-side actions, it is also crucial to promote demand- low-carbon scenarios more concretely, with a focus on side decarbonization (Luderer et  al. 2018; Duscha et  al. electrification pathways. 2019). Sugiyama et al. (2019) shows that the demand-side, There are two dimensions that deserve detailed especially the industry sector, has the difficulty of achieving examination. emissions reductions in Japan’s energy system. First, how high and fast should the share of electricity Energy efficiency improvements are the first and useful increase in the midst of competition from other clean energy contributions in reducing emissions (Fujimori et al. 2014; carriers? Where and how much electrification contributes Sugiyama et al. 2014; Wakiyama and Kuramochi 2017), but to mitigation needs to be assessed, as electricity is not the switching the demand-side to clean energy carriers (electric- only clean energy carrier, and the role of electricity would ity, hydrogen, and bioenergy) is equally important (Deep be different by sectors. Oshiro et al. (2017) shows that for Decarbonization Pathways Project 2015; Ozawa et al. 2018; Japan to achieve an 80% emissions reduction in 2050, it is Matsuo et al. 2018; Gambhir et al. 2019; Wachsmuth and necessary to accelerate the pace of electrification and reach Duscha 2019). In fact, the Government of Japan has intro- the electrification rate of 45% in 2050. However, the long- duced electrification as one of the key policy areas along term energy demand and supply outlook by the Ministry with increasing use of bioenergy and hydrogen (Government of Economy, Trade and Industry (hereinafter called METI of Japan 2019). outlook), which is consistent with Japan’s NDC, shows the Notably, among clean energy carriers, numerous studies share of electricity in final energy (electrification rate) in show that a transition to electricity by the demand-side plays 2030 to be 29%, a mere 3% increase from 2013. a pivotal role in large-scale C O reduction of all demand Second, would decarbonization increase the total sectors on a global, national and urban scale (Sugiyama demand for electricity? Increasing the electrification rate 2012; Williams et al. 2012; Wei et al. 2013, Intergovern- and decreasing the fossil fuel consumption is an effective mental Panel on Climate Change (IPCC) 2014; Quiggin and way to reducing demand-side emissions. However, increas- Buswell 2016; Raghavan et al. 2017; IPCC 2018; Fortes ing the electrification rate does not automatically increase et  al. 2019; Hill et al. 2019; Luh et al. 2020; Zhang and its absolute demand. Sugiyama (2012) reviewed global Fujimori 2020). decarbonization pathways and found the electrification rate Electrification has been incorporated in Japan’s long-term to increase with more stringent emissions targets, but the energy plans. The long-term low-carbon vision (Ministry of absolute demand of electricity did not always increase. the Environment 2016), an input from the Ministry of the These two aspects are both dependent on a number of Environment to the policy debate on the long-term strategy, scenario assumptions as well as models. This study employs listed electrification, including a switch from combustion- the multi-model analytic framework of Energy Modeling engine vehicles to electric vehicles and diffusion of heat Forum (EMF) 35 Japan Model Intercomparison Project pumps for space and water heating, as one of the three pillars (JMIP) and characterizes future electrification pathways for to achieve low-carbon society in Japan. The 2019 long-term Japan to achieve the long-term emissions reduction goals. In strategy submitted by Japan to the United Nations Frame- particular, the present paper takes advantage of a framework work Convention on Climate Change also emphasizes the that includes various power supply technologies scenarios. need to increase electrification rates for 2050. Oshiro et al. (2019) is a notable study in a multi-model In contrast to the policy directions, there are only a few framework which focused on a Japan’s in-depth decar- concrete policies on electrification and most of them have bonization scenario. Although the study shows the share been subsidies or RD&D projects (Government of Japan of clean energy carriers grows in final energy use, elec- 2019). One can contrast this with more drastic measures trification pace, supply-side technology uncertainty, nor such as a ban on ICE cars in the United Kingdom (Govern- the total demand for electricity are analyzed. The present ment of UK 2017) and a proposal of a ban on the use of study attempts to fill the gap by finding a common pattern natural gas in the buildings (Deason and Borgeson 2019) in among results of multiple models of different types to draw a the west coast of the United States of America. 1 3 Sustainability Science (2021) 16:395–410 397 Table 1 Final energy carriers Sector Model Final energy carriers reported by each model b c d Electricity Gases Liquids Solids Hydrogen Other all Heat Solar Other Overall AIM/Enduse X X X X X X X X AIM/Hub X X X X X DNE21 X X X X IEEJ X X X X X X TIMES-Japan X X X X X X X X Industry AIM/Enduse X X X X X AIM/Hub X X X X IEEJ X X X X X X TIMES-Japan X X X X X X X X Residenital AIM/Enduse X X X X X X X AIM/Hub X X X X X IEEJ X X X X X TIMES-Japan X X X X X X X X Commercial AIM/Enduse X X X X X X X X AIM/Hub X X X X X IEEJ X X X X X TIMES-Japan X X X X X X X X Transportation AIM/Enduse X X X AIM/Hub X X X X IEEJ X X X X TIMES-Japan X X X X X Variables that are not reported can be represented in the model. When calculating the emissions, the differ - ence in emissions factors of petroleum, gas, biofuel, etc. is properly taken into consideration In DNE21, demand sector is not modeled separately Gases include natural gas, biogas, coal–gas, excluding transmission/distribution losses Liquids include conventional & unconventional oil, biofuels, coal-to-liquids, gas-to-liquids Solids include coal and solid biomass general conclusion related to the role of electricity in decar- considering numerous detailed technological representation bonizing the demand sector of Japan. in both energy supply and demand sectors, and the latter is a general equilibrium model with relatively aggregated tech- nological resolution but can consider the macroeconomic Methods responses considering the sectoral input–output changes in detail. DNE21, IEEJ and TIMES-Japan are perfect foresight Model description models. Only AIM/Hub is a general equilibrium model, and others are partial equilibrium models. This study employs scenarios from five energy-economic Since energy demand representation is much more het- and integrated assessment models: AIM/Enduse-Japan erogeneous across models than supply-side structures, it is (Oshiro and Masui 2015; Fujimori et al. 2019; Kainuma favorable to have an overview of the decomposition of sec- et al. 2003), AIM/Hub-Japan (Fujimori et al. 2017a, b, c; tors and the inclusion of different final energy carriers. The Silva et al. 2019), DNE21 (Hosoya and Fujii 2011; Fujii and reason for different model behaviors could be attributable to Komiyama 2015), IEEJ_Japan 2017 (Matsuo et al. 2013, which final energy carrier is explicitly represented. 2020), and TIMES-Japan (Kato and Kurosawa 2019; Kuro- Table 1 clarifies final energy carriers by sectors reported sawa and Hagiwara 2012; Loulou et al. 2005; Sato 2005). by the participating models. Electricity is included in all Hereafter, each model is called AIM/Enduse, AIM/Hub, models while hydrogen is represented in AIM/Enduse, IEEJ, DNE21, IEEJ, and TIMES-Japan. AIM/Enduse and AIM/ and TIMES-Japan. Some models do not report biomass- Hub are recursive dynamic models. The former is a typical related carrier (solids biomass, biofuels, and biogas) sepa- energy system model that minimizes total energy system cost rately. These carriers are reported in an aggregated manner 1 3 398 Sustainability Science (2021) 16:395–410 and included in the corresponded carriers (solids, liquids, 26by30 + 80by50_NoCCS: CCS is completely unavail- able. and gases). Note that DNE21 does not explicitly represent energy services by sectors; instead, their demands are rep- In the 26by30 + 80by50_LoVREcost, VRE’s capital cost resented as fuel demands. Also, AIM/Hub does not repre- sent energy services, yet fuel demands are represented for was halved compared to 26by30 + 80by50_Def, but the mod- els did not harmonize the timing of the cost change. Hereaf- each sector. Detailed end-use technologies by models are shown in ESM (Table ESM1 to 4). The more detailed model ter, the scenario prefix “26by30 + 80by50_” is dropped for sensitivity scenarios in this paper for brevity in reporting. descriptions are provided in Sugiyama et al. (2021). We also examine different levels of emissions con- straints. More stringent emissions constraint should accel- Scenarios erate demand-side decarbonization, resulting in higher clean energy carrier shares or electrification rates (Fortes et al. We briefly describe the salient aspects of the scenarios that are analyzed in this paper (see Sugiyama et al. 2021 for 2019). Targeting 2050, we consider 70%, 80%, 90%, and 100% emission reduction levels to understand the impacts fuller descriptions). The central scenario is a mitigation scenario that of climate policies. In addition to 26by30 + 80by50_Def, we explore following scenarios: is consistent with the NDC and mid-century strategy (26by30 + 80by50_Def). The “Baseline” scenario is a sce- 26by30 + 70by50_Def; nario with no climate policy. We also consider an extensive list of sensitivity runs 26by30 + 90by50_Def; and 26by30 + 100by50_Def. on variable renewables (VREs) and nuclear generation. It is now well established that the power sector needs to go In the JMIP study, not all participating models have 90% through almost a complete decarbonization in the long run (IPCC 2014, 2018). Cheap clean electricity makes electri- and 100% C O emissions reduction scenarios in 2050. In AIM/Enduse, 26by30 + 100by50_Def is infeasible, and fication economically competitive, and can further promote demand-side electrification (Zhang et al. 2012). However, in IEEJ and TIMES-Japan, 26by30 + 90by50_Def and 26by30 + 100by50_Def are infeasible. Therefore; pathways the availability of affordable clean electricity depends on multiple technological parameters. It is therefore useful to to achieve net carbon neutrality, a new pledge presented by Prime Minister Suga in October 2020 (Prime Minister’s examine the impact of supply-side sensitivities on demand- side electrification. Office of Japan 2020), could not be elaborated in this paper. This is a future research issue. The JMIP study also explores a scenario regarding the availability of Carbon Capture and Storage (CCS) in addi- tion to VREs and nuclear power generation technology. Since CCS can be deployed both in the power generation Results sector and the industry sector, it can be a crucial technology to decrease demand-side emissions.Overall CO emissions and final energy use in 2050 This paper considers the following scenarios: The CO emissions in 2050 for the 26by30 + 80by50_Def • scenario are around 280Mt-CO (237–336Mt-CO ). The 26by30 + 80by50_LoVREcost: halving the costs of 2 2 VREs; supply side sees a sharp reduction to which the emissions are • less than 100Mt-CO in all models. However, the demand 26by30 + 80by50_HiVREcost: doubling the costs of VREs; sector still emits approximately 200Mt-CO (199–252Mt- • CO ) (see Figure ESM 1.) showing that the demand-side 26by30 + 80by50_LoVREpot: Resource potential for wind and solar halved for 2020 and onwards; reduction is crucial in achieving emissions reduction tar- • gets. The total amount of CO captured and stored is around 26by30 + 80by50_HiVREpot: Resource potential for wind and solar doubled for 2020 and onwards; and 160Mt-CO (23–350Mt-CO ), of which around 40 Mt-CO 2 2 2 • (0–109Mt-CO ) is captured in the demand sector (the indus- 26by30 + 80by50_NoNuc: nuclear power is completely unavailable. try sector, including industrial processes). Since the mid-century strategy does not specify the base year, the base year used to calculate 80% reduction differs among models (2010 in AIM/Enduse, 2005 in AIM/Hub, 2000 in DNE 21, 2013 in IEEJ, and 2013 in TIMES-Japan). 1 3 Sustainability Science (2021) 16:395–410 399 Fig. 1 Final energy use in 2010 and 2050 by fuels in 26by30 + 80by50_Def: a Final energy use in 2010 and 2050, b Difference in final energy use 2010 and 2050, c Fuel share in final energy use in 2010 and 2050, and d Difference of fuel share in final energy use 2010 and 2050 Next, we present final energy (reported in lower heat- hydrogen and gases, see different patterns depending on ing value) by fuel types in 2010 and 2050 for the models. 26by30 + 80by50_Def scenario (Fig. 1). One common trend All models show a substantial decrease in the final energy among the models is a drastic decrease in liquids, mostly oil use from 2010 to 2050. The net final energy use decreases products, by 4.1EJ to 5.5EJ compared to 2010 (the reduction by 5EJ in AIM/Enduse and by 7EJ in IEEJ. Despite simi- rate ranges from 44 to 78%). A similar trend of decreasing lar reduction in liquids and solids, the net final energy consumption is observed in solids, which sees a decrease by use only decreases around 4EJ in AIM/Hub, DNE21, and about 1EJ in all models. Other energy carriers, electricity, TIMES-Japan due to the increasing use of electricity, gas and hydrogen. In AIM/Enduse, most fuels are reduced with only a slight increase in hydrogen and “other all (heat, solar, and other sources)”. In IEEJ, only a slight increase in hydrogen There is a discrepancy in the final energy use in 2010, the base is seen and significant energy savings in all other fuels. In year, as the participating models use different databases and have dif- AIM/Hub, DNE21, and TIMES-Japan electricity, gas and ferent industry sector representation (see Sugiyama et al. 2021). 1 3 400 Sustainability Science (2021) 16:395–410 Fig. 2 CO emissions and CO 2 2 reduction rate by demand-side sectors in 26by30 + 80by50_ Def: a CO emissions in 2010 and 2050, and b CO reduction rate in 2050 from 2010. Note: DNE21 does not report CO emissions by sectors hydrogen increase while fossil fuel consumption reduces. In CO emissions and final energy use by sectors AIM/Hub, a significant increase in electricity consumption in 2050 is observed. In DNE21, electricity and gases increase. In TIMES-Japan, electricity, gases, and hydrogen significantly The overall direct CO emissions reduction rate of the increase. demand-side from 2010 to 2050 is approximately 70%, but The electricity demand stays at a relatively the same the reduction rates by sectors vary across models as shown level compared to the current consumption, 3.0–4.5EJ in Fig. 2. The CO emissions reduction rates are 50–84% in (840–1260TWh), with one exception of AIM/Hub which the industry sector including industrial processes, 36–82% sees a sharp increase to 7.0EJ (1950TWh) in 2050. In terms in the residential sector, 34–100% in the commercial sector, of the absolute electricity demand, both results of increasing and 54–93% in the transportation sector. and decreasing were seen among models, which is consist- The CO emissions in the transportation sector are the ent with the findings of Sugiyama (2012). Despite the level smallest in AIM/Enduse while they are the largest in AIM/ of consumption staying relatively flat in 2050, the electri- Hub. Both in IEEJ and TIMES-Japan, the largest emitting fication rate increases in all models (AIM/Enduse: 37%; sector is the industry sector and the smallest is the com- AIM/Hub: 66%; DNE21: 39%; IEEJ: 44%; TIMES: 43%) mercial sector. However, in IEEJ, the C O emissions of the compared to around 26% in 2010 as the total final energy residential sector is about half of the transportation sector, use decreases. The electrification rates increase at a pace of but in TIMES-Japan, the residential sector and the transpor- 0.03–0.45%/year from 2010 to 2030, but increase at a faster tation sector have almost the same CO emissions. pace of 0.46–1.58%/year from 2030 to 2050. The variation among models is caused by the differences With regards to other clean energy carriers, a notable in final energy use changes in each sector from 2010 to 2050. increase in hydrogen is seen in IEEJ and TIMES-Japan mod- Figure 3. shows the differences among models in the final els, providing around 10% of final energy in 2050 (AIM/Hub energy use by fuels in industry, residential, commercial, and and DNE21 have no hydrogen option). transportation sectors in 2010 and 2050. The industry sec- tor continues to be the most consuming sector in all models despite the largest decrease in the final energy use among all sectors in most models. The transport sector goes through a rapid transition with a rapid decline in use of liquids (mostly AIM/Hub’s large increase in the electricity consumption is con- oil products). tributed to the way demands are determined. AIM/Hub is the only The final energy use in the industry sector in 2050 ranges general equilibrium model within this comparison, which determines between 3.3 and 5.7EJ, and the electricity consumption energy use by CES (Constant-Elasticity-of Substitution) function rather than energy services. ranges between 0.8 and 2.5EJ. The share of final energy 1 3 Sustainability Science (2021) 16:395–410 401 Fig. 3 Final energy use by fuel type by sector in 2010 and 2050 in e Final energy use in commercial sector in 2010 and 2050, f Differ - 26by30 + 80by50_Def: a Final energy use in industry sector in 2010 ence in final energy use 2010 and 2050 in commercial sector, g Final and 2050, b Difference in final energy use 2010 and 2050 in indus- energy use in transportation sector in 2010 and 2050, and h Differ - try sector, c Final energy use in residential sector in 2010 and 2050, ence in final energy use 2010 and 2050 in transportation sector d Difference in final energy use 2010 and 2050 in residential sector, use by the industry sector in 2050 is 32–60%, close to half up most of the demand. The reduction in liquids demand in three models. The industry sector transforms its energy is a major movement in the residential sector as the liquids composition largely dependent on liquids and solids (around demand decreases to less than 0.1EJ in three models, imply- 60% in all models) in 2010 to delivering half of its energy ing that oil water heater and stoves are virtually phased out from electricity, gases and hydrogen in 2050. Although the in the residential sector (Oshiro and Fujimori 2020). Most largest reduction is seen in liquids, the consumption of liq- models see a decrease in the final energy demand, but AIM/ uids still stays high around 1.2EJ in all models. Solids are Hub sees an increase as the increase in electricity demand also reduced in all models, but most models still use around surpasses the decrease in liquids demand. 0.6EJ in 2050. The final energy use in the commercial sector in 2050 The final energy use in the residential sector ranges is 1.3–2.4EJ, of which electricity is the major energy car- between 1.2 and 2.4EJ of which gases and electricity make rier. The use of liquids and gases are greatly reduced and 1 3 402 Sustainability Science (2021) 16:395–410 Fig. 4 Share of fuels in final energy by sectors in 2010 and 2050 in 26by30 + 80by50_Def: a Industry sector, b Residential sector, c Commercial sector, and d Transportation sector almost no longer consumed (0–0.02EJ for liquids, 0–0.2EJ electrification rates is attributed also to the increasing con- for gases) except for AIM/Enduse which has a relatively sumption of electricity along with decreasing consumption large CO emissions in the commercial sector. This implies of other fuels (see also Fig. 3). that nearly all oil and gas appliances (mainly cooking, water In the industry sector, the electrification rate stays the heater, and space heating) needs to be phased out in this sec- lowest among sectors at around 20%, an increase of only a tor to reach emissions reduction targets. few percentage points from 2010. One exception is the AIM/ The transportation sector sees a rapid transformation from Hub (the only participating GE model), in which rapid elec- heavily liquids dependent energy composition to a more trification takes place up to 73% in 2050.In the residential mixed composition. Other than AIM/Hub, which does not sector, the electrification rate is the highest among all fuels model hydrogen, models see an increase in both electric- in all models (46–75%), showing the importance in elec- ity and hydrogen. The electricity consumption increases to trifying the residential end-use technologies. On the other 0.3–0.6EJ, whereas the hydrogen consumption increases to hand, the share of liquids (mostly oil products) decrease sig- 0.1–0.6EJ. Since most of the energy use in the transporta- nificantly suggesting a need to initiating a phase out of oil tion sector was oil products in 2010, liquids consumption water heater and stoves. The commercial sector, which has decreases by 1.3–2.5EJ. The replacing technologies (elec- the highest electrification rate across sectors in all models tric vehicles and hydrogen vehicles) typically have higher (62–95%), sees the use of liquids disappear in three models efficiency, so the final energy use in the sector reduces to implying limited use of oil and gas appliances (mainly for 1.0–2.4EJ. The share of transportation sector in overall final cooking, hot water, and space heating) in a decarbonized energy, which was around 25% in 2010, decreases to around society. The transport sector sees a great increase in the 15% in most models. share of electricity. In 2010 the share is very low at around Figure 4 shows fuel share of final energy use by sectors 2%, but it increases to 20–40% in models. in 2010 and 2050. Two trends observed in all sectors from As a complement, the share of hydrogen, a clean 2010 to 2050 are the decrease in the share of liquids and the energy carrier competing with electricity, is described increase in electrification rates (with the exception of the by sector. In the industry sector, hydrogen is introduced residential sector’s electricity share in the AIM/Enduse). The in 2050 with a share of 9% and 7% in IEEJ and TIMES- electrification rates increase mainly due to decreasing con- Japan respectively, while the electrification rates reach sumption of other fuels in the industry and residential sec- 23% and 29%. Likewise, in the transport sector, both tors. In the commercial and transport sectors, the increasing electricity and hydrogen are introduced in 2050. In AIM/ 1 3 Sustainability Science (2021) 16:395–410 403 Fig. 5 Carbon intensity in 2010 and 2050 and relationship to elec- electrification rate and carbon intensity by sector in 2050. Note: Car - trification rate by sector in 2050 in 26by30 + 80by50_Def: a Carbon bon intensity calculates by only direct emissions without CCS in intensity by sector in 2010 and 2050, and b The relationship between industry sector Enduse, electricity is 20% while hydrogen is 7% and in Sensitivity analysis IEEJ, electricity is 24%, hydrogen is 19%. In TIMES- Japan, the share of hydrogen is higher than electricity, VREs and nuclear generation sensitivity with electricity at 40% while hydrogen at 44%. Carbon intensity (the emission amount per unit final In order to analyze the effects of available VREs and nuclear energy use) is reduced across all models in 2050. Look- generation, scenarios with high and low VRE costs, high ing at the C O emissions (Fig. 2) and the final energy use and low VRE resource potential, and no nuclear (LoVRE- (Fig.  3) in each sector from 2010 to 2050, the demand cost, HiVREcost, HiVREpot, LoVREpot, and NoNuc) are sector’s carbon intensities in 2010 is 48–56 g-CO /MJ, compared. Figure 6 shows the share of energy carriers in but they are reduced to 22–29 g-CO /MJ in 2050 (Fig. 5). each scenario by models. Although electrification rates are The lowest carbon intensity is seen in the commercial sec- different in each model, all models maintain electrification tor (0–22 g-CO /MJ), followed by the residential sector rates close to the level of 26by30 + 80by50_Def scenario (11–28 g-CO /MJ). The model average of carbon inten- as the change ranges between − 4.3 and + 6.5%pt (see also sity in the industry sector including industrial processes Figure ESM3). (28 g-CO /MJ) and the transportation sector (30 g-CO / A notable change in the share of n fi al energy is seen in the 2 2 MJ) remain to be high-emitting sectors. following scenarios. AIM/Enduse shows a higher electrifi - The carbon intensity strongly depends on the ratio of cation rate (+ 1.2%pt) in the HiVREcost scenario than the fuel types in the final energy use. The value of carbon 26by30 + 80by50_Def scenario because the electricity con- intensity increases as the share of fossil fuels increases, sumption is slightly higher (+ 0.01EJ) while the final energy and the carbon intensity decreases as the share of use decreases by 0.24EJ. In AIM/Hub, the electrification rate clean energy carriers, such as electricity and hydrogen, decreases from the 26by30 + 80by50_Def scenario in the increase. Therefore, sectors with high electrification rates HiVREcost (− 4.3%pt) and the NoNuc (− 2.2%pt) scenarios have low-carbon intensities as shown in Fig. 5 and con- by increasing liquids consumption, while the electrification tribute greatly in reducing the demand-side emissions. rate increases from the 26by30 + 80by50_Def scenario in the 1 3 404 Sustainability Science (2021) 16:395–410 Fig. 6 Final energy mix in 2050 in VREs and nuclear generation sensitivity scenarios LoVREcost (+ 4.5%pt) and the HiVREpot (2.1%pt) scenar- Models maintain electrification rates close to the level of ios by decreasing liquids consumption. In DNE21, only the 26by30 + 80by50_Def scenario as the change ranges only NoNuc scenario shows a slight decrease in the electrification between − 0.2 and + 1.8%pt. One exception is AIM/Enduse, rate (− 0.2%pt) from 26by30 + 80by50_Def because DNE21 which sees a notable increase of 8.8%pt as over 100Mt of has a high share of nuclear power generation due to no quan- CCS is deployed on the demand side (around 110Mt-CO tity constraint (see Shiraki et al. 2021) in 26by30 + 80by50_ in the industry sector including industrial processes) in Def. IEEJ and TIMES-Japan models show a competitive 26by30 + 80by50_Def. When CCS is not available, AIM/ nature between VRE and hydrogen. Hydrogen consumption Enduse decreases gas consumption and increases electricity decreases when more VREs electricity becomes accessible demand to reduce CO emissions in the residential and com- (LoVREcost and HiVREpot), while hydrogen consumption mercial sectors to compensate for the increasing emissions increases when electricity from VREs and nuclear becomes in the industry sector. limited (HiVREcost, LoVREpot and NoNuc). The electrification rate correlates positively with the Emissions policy sensitivity availability of VREs and nuclear power sources, but the cases considered in this modeling exercise were not enough Figure 8 shows the changes in the share of final energy carri- to change the electrification rates drastically. When avail- ers when the emission reduction target for 2050 is 70%, 80%, ability of nuclear is restricted, VRE replaced the genera- 90%, and 100% (26by30 + 70by50_Def, 26by30 + 80by50_ tion and vice versa. In summary, the cost and availability of Def, 26by30 + 90by50_Def, and 26by30 + 100by50_Def). VREs and nuclear generation does not change the need for Some models were not able to provide results as the emis- electrifying the demand sector to achieve the 80% reduction sions policy became extremely stringent. (26by30 + 90by50_ in 2050. Def: IEEJ, TIMES-Japan; 26by30 + 100by50_Def: AIM/ Enduse, IEEJ and TIMES-Japan). CCS sensitivity When a stricter emissions reduction policy is applied, the electrification rates increase in all models (Fig.  9), show- Figure  7 shows the share of final energy carriers and ing the importance of electricity as a clean energy carrier CO emissions in the NoCCS scenario by models. in the demand sector. Electricity typically replaces gases 1 3 Sustainability Science (2021) 16:395–410 405 Fig. 7 Final energy use and C O emissions in 2050 in CCS sensitivity scenario: a Final energy use and b CO emissions (26by30 + 80by50_Def 2 2 and 26by30 + 80by50_NoCCS). Note: DNE21 does not report CO emissions by sectors. DNE21 are not classified and liquids, but in some models (DNE21, IEEJ) the gases In DNE21, the electricity consumption stays the same consumption increases with tighter emissions targets. An from 70 to 90% reduction targets at 4.5EJ (1260TWh) but increase in hydrogen consumption with tighter emissions increases to 4.7EJ (1300TWh) in 100% reduction target. targets is also observed in AIM/Enduse, IEEJ and TIMES- The consumption of liquid decreases from 6.6 to 2.3EJ as Japan, all the models with a hydrogen option. the emission target gets tighter from 70 to 100% as in all In AIM/Enduse, electricity consumption increases from models, but the consumption of gases increases from 1.8 3.1 to 3.7EJ (860–1030TWh) as the emissions target gets to2.7EJ. tighter from 70 to 90%. The biggest reduction seen is in In IEEJ, the electricity consumption increases from 2.9 gases as the consumption decreases from 2.0 to 0.9EJ fol- to 3.0EJ (820–830TWh) as the emissions target gets tighter lowed by liquids from 2.3 to 1.9EJ. from 70 to 80%. The coal and liquids demand decrease as in AIM/Hub’s electricity consumption increases from 6.5 to other models, but the biggest increase is seen in hydrogen 7.8EJ (1800–2160TWh) as the emissions target gets tighter which increases from close to zero to 0.5EJ. from 70 to 100%. The increase in the electricity consump- tion replaces gases and liquids as the gases decrease from 0.8 to 0.1EJ, and liquids decrease from 4.4 to 1.0EJ. 1 3 406 Sustainability Science (2021) 16:395–410 Fig. 8 Final energy use by fuel type in 2050 in emissions policy scenarios Discussion Electrification pace and METI outlook The METI outlook assumes the final energy use in 2030 to be reduced by 14% (14.4–12.4EJ) while the electricity consumption to be reduced by only 5% (3.7–3.5EJ) com- pared to 2010. Since the final energy reduction rate is higher, the METI outlook recommends electrification rate to be increased from 26 to 29% or the electrification rate to increase at the pace of 0.15%/year. The electricity rate in Japan has increased from 13% in 1970 to 28% in 2018. Looking at a 20-years span, the annual percent change in electrification has been 0.37%/year from 1970 to 1990, and 0.30%/year from 1990 to 2010. Since 2011 the pace of electrification has slowed down to 0.18%/ Fig. 9 Electrification rate and emissions reduction targets in 2050 year from 2010 to 2018. In the 26by30 + 80by50_Def scenario, the electrification In TIMES-Japan, the electricity consumption increases rates increase at a pace of 0.03–0.45%/year from 2010 to from 3.9 to 4.1EJ (1090–1130Wh) as the emissions tar- 2030, showing that the historical rates and the rate assumed get gets tighter from 70 to 80%. Like IEEJ, the TIMES- by METI outlook could be enough to reach the 2030 target Japan sees a decrease in liquids and gases while hydrogen (Fig. 10). However, as mentioned in the results section, the increases the most from 0.3 to 1.2EJ. electrification pace must be accelerated from 2030 to 2050 and need to reach the range of 0.46–1.58%/year. This pace is 1.5–5.3 times higher than the historical average of 0.30%/ year (199–2010), a period of relatively electrification leading 1 3 Sustainability Science (2021) 16:395–410 407 Fig. 10 Electrification rate from 1980 to 2050 in Historical, Baseline and 26by30 + 80by50_Def: a Electrification rate from 1980 to 2050, b Electrification rate in 2030 and 2050, and c Average of annual change in electrification rate from 2010 to 2030 and 2030 to 2050 up to the 2011 Tohoku earthquake and tsunami. Taking into that the electrification pace needs to be increased. While consideration that the pace of electrification in the baseline there are variations in the electric fi ation rates and electricity scenario, a scenario without a climate policy, is 0.14–0.49%/ demand by sectors among models, a common trend in end- year from 2030 to 2050 in the 26by30 + 80by50_Def in use technology was observed in the residential, commercial 2050, increasing electrification rates to achieve 80% reduc- and transportation sectors. The use of oil water heater and tion in 2050 will require additional policy measures. Mul- stoves decreases in the residential sector and gas appliances tiple studies (Seto et al. 2016; Unruh 2000) have pointed decreases in the commercial sector. In the transportation sec- out that a lock-in mechanism could delay the diffusion of tor, fossil fuel vehicles decreased significantly, while they technologies. Policies and measures to alleviating the lock-in were replaced by electric and fuel cell vehicles. There is mechanism which can delay electrification need be consid- a big difference among models in terms of the timing and ered to increase the pace of electrification suggested by the pace of electrification by sectors, but there is a clear conclu - models to achieve the emissions reduction target. Policy- sion that the overall electrification rate of the demand sector makers could refer to some advanced electrification meas- needs to be increased. A detailed analysis of the differences ures recently taken to decarbonize buildings by several US between the models of electrification pace by sector is a states. The measures include obligation or recommendation topic for the future. Since Ju et al. (2021) reports results of to electrify new buildings, installation assistance for electri- energy use in the industry sector in details from the same cal equipment, the requirement for electrification ready, and Model Intercomparison project. providing consumers with information on benefits such as It is also important to note that reducing emission comfort and controllability of electrical equipment (Nishio intensity of electricity is a prerequisite for mitigation and Nakano 2020). through electrification (Zhang and Fujimori 2020). In the Looking further into the sectoral electrification rates, 26by30 + 80by50_Def scenario, the model results show the there is no consensus among the models on the pace of elec- emission intensity of electricity sharply decreases from 2040 trification. Only in the transportation sector alone, which to 2050, but a lock-in mechanism also applies to the supply currently has a very low electrification rate, all models show sector. Along with accelerating the pace of electrification, 1 3 408 Sustainability Science (2021) 16:395–410 the emission intensity of electricity should be reduced as zero emissions in 2050, it is necessary to consider the role accordingly from an early stage. of biomass together with hydrogen in the future analysis of electrification. Electricity and hydrogen The two clean energy carriers introduced with a notable Conclusion share in 2050 in this modeling comparison exercise are elec- tricity and hydrogen. In two models in which hydrogen is not In this study, we analyzed the change in energy use structure modeled, AIM/Hub and DNE21, electricity is chosen as the of the demand sector in scenarios achieving 80% reduction clean energy carrier. In other three models (AIM/Enduse, in 2050, Japan’s long-term reduction target, focusing on the IEEJ and TIMES-Japan), hydrogen is introduced along with role of electricity. electricity to decarbonize the demand sectors. Hydrogen is In order to achieve the long-term reduction target, it is mainly introduced in the industry and transportation sectors, necessary to significantly reduce CO emissions not only as hydrogen is a good option for hard to electrify demands in the supply side but also in the demand side. The model such as high temperature industrial heat demands, heavy results of the scenario that is consistent with the NDC and trucks and ships. The residential and commercial sectors mid-century strategy show approximately 70% reductions also have limited end-use technologies options available for in the demand-side emissions in this modeling comparison. hydrogen. The reduction is contributed to a significant reduction in the If we turn to the supply side, typically hydrogen is pro- final energy use, especially fossil fuels, while maintaining or duced by electrolysis of water using carbon free electric- increasing consumption of low emission intensity electricity. ity (International Energy Agency 2019), so the domestic The electrification rate increases mainly due to switching hydrogen production is directly related to an increase in the from fossil fuel end-use technologies (i.e. oil water heater, supply-side electricity generation, not electricity demand oil stove and combustion-engine vehicles) to electricity end- in the demand sectors (see Figure ESM 4). In TIMES- use technologies (i.e. heat pump water heater and electric Japan, the electricity generation jumps to nearly 2000TWh vehicles). in the HiVREpot scenario compared to 1350TWh in the The pace at which electrification rate must be increased 26by30 + 80by50_Def scenario (Note that electricity con- is a challenge. Electrification has been advancing as a trend, sumption in Fig.  6 does not include the electricity con- but neither the past electrification pace nor the outlook of sumption for hydrogen production, which is categorized as the Ministry of Economy, Trade and Industry is enough to secondary energy use), as hydrogen is produced domesti- reach the suggested electrification rate of 37–66% suggested cally using more readily available wind and solar. Such an by the models in 2050. Therefore, a more focus should be increase in the amount of power generated for hydrogen given on demand side electrification in the long-term strat- production is regarded as indirect electrification. For exam- egy, and more concrete measures, such as banning the sale ple, net zero emissions scenario of the UK Committee on of combustion-engine vehicles by UK or requiring building Climate Change (2019) and Capros et al. (2019) explicitly electrification as in Berkeley, to accelerate dissemination of takes into account that the amount of electricity required electricity end-use technologies across all sectors need to for electrolysis of water will occur at a level comparable to be established. the electricity demand of the traditional demand sector. It is also possible to import hydrogen; in which case the domestic Supplementary Information The online version contains supplemen- electricity generation is not affected. Such a case is IEEJ, in tary material available at https: //doi.org/10.1007/s11625 -021-00935- w. which all of hydrogen consumed in the model is imported. Acknowledgements This research was supported by the Environment Although METI outlook only explicitly considers elec- Research and Technology Development Fund 2-1704 of the Environ- tricity for the demand sector in 2030, hydrogen along with mental Restoration and Conservation Agency. KO was supported by electricity could play a vital role in the future energy mix. JSPS KAKENHI Grant Number JP20K14860 and the Environmental By 2050, innovation could open the possibility of afford- Research and Technology Development Fund (JPMEERF20201002) of the Environmental Restoration and Conservation Agency of Japan. SF able domestic hydrogen production options. Therefore, the and KO were supported by Sumitomo Foundation. SS was supported amount of electricity generation possibly required to pro- by the Integrated Research Program for Advancing Climate Models duce hydrogen should be carefully considered in the discus- (TOUGOU) Grant Number JPMXD0717935457 from the Ministry of sion for the energy mix of 2050, for example, in the revision Education, Culture, Sports, Science and Technology (MEXT), Japan. RK was supported by JSPS KAKENHI Grant Number JP20H02679 of the basic energy plan. and JP17H03531. DSH was supported by the Environmental Research We did not discuss the role of biomass, which is one of and Technology Development Fund (JPMEERF20201002) of the Envi- the low-carbon carriers, in this study. Since biomass could ronmental Restoration and Conservation Agency of Japan and by the play an important role in extreme reduction scenarios, such Strategic Operation Fund and the Strategic Research Fund of IGES. 1 3 Sustainability Science (2021) 16:395–410 409 Open Access This article is licensed under a Creative Commons Attri- Government of Japan (2019) The long-term strategy under the bution 4.0 International License, which permits use, sharing, adapta- paris agreement. https ://unfcc c.int/sites /defau lt/files /resou rce/ tion, distribution and reproduction in any medium or format, as long The%20Long-ter m%20Strategy %20und er%20t he%20P aris%20 as you give appropriate credit to the original author(s) and the source, Agr eemen t.pdf provide a link to the Creative Commons licence, and indicate if changes Government of UK (2017) UK plan for tackling roadside nitrogen were made. The images or other third party material in this article are dioxide concentrations. https ://asset s.publi shing .servi ce.gov. included in the article’s Creative Commons licence, unless indicated uk/go v er nment /uploa ds/sy s te m/uploa ds/att ac hment _dat a/ otherwise in a credit line to the material. If material is not included in file/63327 0/air-quali ty-plan-detai l.pdf the article’s Creative Commons licence and your intended use is not Hill G, Heidrich O, Creutzig F, Blythe P (2019) The role of elec- permitted by statutory regulation or exceeds the permitted use, you will tric vehicles in near-term mitigation pathways and achieving need to obtain permission directly from the copyright holder. To view a the UK’s carbon budget. Appl Energy 251:113111. https ://doi. copy of this licence, visit http://creativ ecommons .or g/licenses/b y/4.0/.org/10.1016/j.apene rgy.2019.04.107 Hosoya Y, Fujii Y (2011) Analysis of energy strategies to halve CO emissions by the year 2050 with a regionally disaggregated world energy model. Energy Procedia 4:5853–5860 References Intergovernmental Panel on Climate Change (2014) Climate Change 2014: Mitigation of Climate Change. Contribution of Working Capros P, Zazias G, Evangelopoulou S, Kannavou M, Fotiou T, Sis- Group III to the Fifth Assessment Report of the Intergovern- kos P, Vita A, Sakellaris K (2019) Energy-system modelling mental Panel on Climate Change, Cambridge University Press of the EU strategy towards climate-neutrality. Energy Policy Intergovernmental Panel on Climate Change (2018) Global Warm- 134:110960. https ://doi.org/10.1016/j.enpol .2019.11096 0 ing of 1.5 °C: An IPCC Special Report on the impacts of global Committee on Climate Change (2019) Net Zero – Technical Report. warming of 1.5 °C above pre-industrial levels and related global https://www .theccc.or g.uk/publicatio n/ne t-zero-technical-r epor greenhouse gas emissions pathways, in the context of strength- t/ ening the global response to the threat of climate change, sus- Deason J, Borgeson M (2019) Electrification of buildings: poten- tainable development, and efforts to eradicate poverty tial, challenges, and outlook. Curr Sustain Renew Energy Rep International Energy Agency (2019) The future of hydrogen. Seiz- 6:131–139. https ://doi.org/10.1007/s4051 8-019-00143 -2 ing today’s opportunities. https://www .iea.org/reports/t he-futur Deep Decarbonization Pathways Project (2015) Pathways to deep e-of-hydro gen Decarbonization 2015 synthesis report. https ://www.iddri .org/ Ju Y, Sugiyama M, Kato E et al (2021) Industrial decarbonization en/publi catio ns-and-event s/repor t/pathw ays-deep-decar boniz under Japan’s national mitigation scenarios: a multi-model anal- ation -2015-synth esis-repor t ysis. Sustain Sci. https ://doi.org/10.1007/s1162 5-021-00905 -2 Duscha V, Denishchenkova A, Jakob Wachsmuth J (2019) Achiev- Kainuma M, Matsuoka Y, Morita T (2003) Climate policy assess- ability of the Paris agreement targets in the EU: demand-side ment: Asia-Pacific integrated modeling. Springer, Tokyo reduction potentials in a carbon budget perspective. Clim Policy Kato E, Kurosawa A (2019) Evaluation of Japanese energy sys- 19(2):161–174. https ://doi.org/10.1080/14693 062.2018.14713 tem toward 2050 with TIMES-Japan—deep decarboniza- 85 tion pathways. Energy Procedia 158:4141–4146. https ://doi. Fortes P, Simoes S, Gouveia J, Seixas J (2019) Electricity, the silver org/10.1016/j.egypr o.2019.01.818 bullet for the deep decarbonisation of the energy system? Cost- Kurosawa A, Hagiwara N (2012) Long term energy system analysis effectiveness analysis for Portugal. Appl Energy 237:292–303. of Japan after March 11, 2011, 3rd IAEE Asian Conference, https ://doi.org/10.1016/j.apene rgy.2018.12.067 February 21. https://enek en.ieej.or .jp/3rd_IAEE_Asia/pdf/paper Fujii Y, Komiyama R (2015) Long-term energy and environmental /106p.pdf. [accessed 29 May 2020] strategies. In: Ahn J, Carson C, Jensen M, Juraku K, Nagasaki Loulou R, Remne U, Kanudia A, Lehtila A, Goldstein G (2005) S, Tanaka S (eds) Reflections on the Fukushima Daiichi nuclear Documentation for the TIMES model—part I. http://iea-etsap accident. Springer, pp 105–115.org/docs/TIMES Doc-Intro .pdf. [accessed 29 Apr 2020] Fujimori S, Kainuma M, Masui T, Hasegawa T, Dai H (2014) The Luderer G, Vrontisi Z, Bertram C, Edelenbosch OY, Pietzcker RC, effectiveness of energy service demand reduction: a scenario Rogelj J, De Boer HS, Drouet L, Emmerling J, Fricko O, Fuji- analysis of global climate change mitigation. Energy Policy mori S, Havlík P, Iyer G, Keramidas K, Kitous A, Pehl M, Krey 75:379–391. https ://doi.org/10.1016/j.enpol .2014.09.015 V, Riahi K, Saveyn B et al (2018) Residual fossil C O emissions Fujimori S, Hasegawa S, Masui T (2017a) AIM/CGE V2.0: basic in 15–2 °C pathways. Nat Clim Change 8(7):626–633. https :// feature of the model. In: Fujimori S, Kainuma M, Masui T doi.org/10.1038/s4155 8-018-0198-6 (eds) Post-2020 climate action global and Asian perspective. Luh S, Budinis S, Giarola S, Schmidt T, Hawkes A (2020) Long- Springer, pp 305–328 term development of the industrial sector—Case study about Fujimori S, Hasegawa T, Masui T, Takahashi K, Silva Herran D, Dai electrification, fuel switching, and CCS in the USA. Comput H, Hijioka Y, Kainuma M (2017b) SSP3: AIM implementa- Chem Eng 133:106602. https: //doi.org/10.1016/j.compc hemen tion of shared socioeconomic pathways. Glob Environ Chang g.2019.10660 2 42:268–283. https ://doi.org/10.1016/j.gloen vcha.2016.06.009 Matsuo Y, Endo S, Nagatomi Y, Shibata Y, Komiyama R, Fujii Y Fujimori S, Masui T, Matsuoka Y (2017c) AIM/CGE V2.0 model (2020) Investigating the economics of the power sector under formula. In: Fujimori S, Kainuma M, Masui T (eds) Post-2020 high penetration of variable renewable energies. Appl Energy climate action: global and Asian perspective. Springer, pp 267:113956. https ://doi.org/10.1016/j.apene rgy.2019.11395 6 201–303 Matsuo Y, Yanagisawa A, Yamashita Y (2013) A global energy out- Fujimori S, Oshiro K, Shiraki H, Hasegawa T (2019) Energy trans- look to 2035 with strategic considerations for Asia and Mid- formation cost for the Japanese mid-century strategy. Nat Com- dle East energy supply and demand interdependencies. Energy mun 10(1):4737. https ://doi.org/10.1038/s4146 7-019-12730 -4 Strategy Rev 2:79–91. https://d oi.org/10.1016/j.esr.2013.04.002 Gambhir A et al (2019) Energy system changes in 1.5 °C, well below Matsuo Y et  al (2018) A quantitative analysis of Japan’s opti- 2 °C and 2 °C scenarios. Energy Strategy Rev 23:69–80. https mal power generation mix in 2050 and the role of CO -free ://doi.org/10.1016/j.esr.2018.12.006 1 3 410 Sustainability Science (2021) 16:395–410 hydrogen. Energy 165:1200–1219. https ://doi.or g/10.1016/j. uncertain nuclear policy. Clim Policy 19(9):1117–1131. https:/ / energ y.2018.09.187doi.org/10.1080/14693 062.2019.16345 07 Ministry of the Environment (2016) Long-term, low-carbon vision. Sugiyama M (2012) Climate change mitigation and electrification. https ://www.env.go.jp/counc il/06ear th/y0618 -14/mat03 -1.pdf Energy Policy 44:464–468. https ://doi.or g/10.1016/j.en pol Ministry of the Environment. https ://www.env.go.jp/earth /ondan ka/ .2012.01.028 ghg-mrv/emiss ions/resul ts/mater ial/kakuh ou_all_2018.pdf Sugiyama M, Akashi O, Wada K, Kanudia A, Li J, Weyant J (2014) Nishio K, Nakano K (2020) Study on initiatives for building decar- Energy efficiency potentials for global climate change mitigation. bonization-Case studies of US states and local governments and Clim Change 123(3–4):397–411. https ://doi.org/10.1007/s1058 implications for Japan-, CRIEPI Research Report, Y19005. (in 4-013-0874-5 Japanese) Sugiyama M, Fujimori S, Wada K, Endo S, Fujii Y, Komiyama R, Kato Oshiro K, Masui T (2015) Diffusion of low emission vehicles and E, Kurosawa A, Matsuo Y, Oshiro K, Sano F, Shiraki H (2019) their impact on C O emission reduction in Japan. Energy Policy Japan’s long-term climate mitigation policy: multi-model assess- 81:215–225. https ://doi.org/10.1016/j.enpol .2014.09.010 ment and sectoral challenges. Energy 167:1120–1131. https: //doi. Oshiro K et al (2017) Implications of Japan’s 2030 target for long-term org/10.1016/j.energ y.2018.10.091 low emission pathways. Energy Policy 110:581–587. https ://doi. Sugiyama M, Fujimori S, Wada K et al (2021) EMF 35 JMIP study org/10.1016/j.enpol .2017.09.003 for Japan’s long-term climate and energy policy: scenario designs Oshiro K, Gi K, Fujimori S, van Soest HL, Bertram C, Després J, and key findings. Sustain Sci. https://doi.or g/10.1007/s11625-021- Masui T, Rochedo P, Roelfsema M, Vrontisi Z (2019) Mid-cen-00913 -2 tury emission pathways in Japan associated with the global 2 °C Unruh G (2000) Understanding carbon lock-in. Energy Policy 28:817– goal: National and global models’ assessments based on carbon 830. https ://doi.org/10.1016/S0301 -4215(00)00070 -7 budgets. Clim Change. https://doi.or g/10.1007/s10584-019-02490 Wachsmuth J, Duscha V (2019) Achievability of the Paris targets in the -x EU—the role of demand-side-driven mitigation in different types Oshiro K, Fujimori S (2020) Stranded investment associated with rapid of scenarios. Energ Effi 12:403–421. https ://doi.or g/10.1007/ energy system changes under the mid-century strategy in Japan. s1205 3-018-9670-4 Sustain Sci. https ://doi.org/10.1007/s1162 5-020-00862 -2 Wakiyama T, Kuramochi T (2017) Scenario analysis of energy saving Ozawa A et al (2018) Hydrogen in low-carbon energy systems in Japan and CO2 emissions reduction potentials to ratchet up Japanese by 2050: the uncertainties of technology development and imple- mitigation target in 2030 in the residential sector. Energy Policy mentation. Int J Hydrogen Energy 43:18083–18094. https ://doi. 103:1–15. https ://doi.org/10.1016/j.enpol .2016.12.059 org/10.1016/j.ijhyd ene.2018.08.098 Wei M, Nelson J, Greenblatt J, Mileva A, Johnston J, Ting M, Yang Quiggin D, Buswell R (2016) The implications of heat electrifica- C, Jones C, McMahon J, Kammen D (2013) Deep carbon reduc- tion on national electrical supply-demand balance under pub- tions in California require electrification and integration across lished 2050 energy scenarios. Energy 98:253–270. https ://doi. economic sectors. Environ Res Lett 8(1):014038. https ://doi. org/10.1016/j.energ y.2015.11.060org/10.1088/1748-9326/8/1/01403 8 Prime Minister’s Office of Japan (2020) Prime Minister Suga’s Williams J et  al (2012) The technology path to deep greenhouse statement of belief. https ://www .k ante i.go.jp/jp/99_sug a/s t ate gas emissions cuts by 2050: pivotal role of electricity. Science ment/2020/1026s hoshi nhyom ei.html 335:53–59. https ://doi.org/10.1126/scien ce.12083 65 Raghavan S, Wei M, Kammen D (2017) Scenarios to decarbonize resi- Zhang Q, Ishihara K, Mclellan B, Tezuka T (2012) Scenario analysis dential water heating in California. Energy Policy 109:441–451. on future electricity supply and demand in Japan. Energy 38:376– https ://doi.org/10.1016/j.enpol .2017.07.002 385. https ://doi.org/10.1016/j.energ y.2011.11.046 Sato O (2005) A study on long-term energy scenarios for Japan. Zhang R, Fujimori S (2020) The role of transport electrification in JAERI-Res. https ://doi.or g/10.11484 /jaer i -r esea r c h-2005-012 global climate change mitigation scenarios. Environ Res Lett ((in Japanese) [accessed May 29, 2020]) 15:034019. https ://doi.org/10.1088/1748-9326/ab665 8 Seto K et al (2016) Carbon lock-in: types, causes, and policy impli- cations. Annu Rev Environ Resour 41:425–452. https ://doi. Publisher’s Note Springer Nature remains neutral with regard to org/10.1146/annur ev-envir on-11061 5-08593 4 jurisdictional claims in published maps and institutional affiliations. Shiraki H, Sugiyama M, Matsuo Y et al (2021) The role of renewables in the Japanese power sector: implications from the EMF35 JMIP. Sustain Sci. https ://doi.org/10.1007/s1162 5-021-00917 -y Silva HD, Fujimori S, Kainuma M (2019) Implications of Japan’s long term climate mitigation target and the relevance of 1 3 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Sustainability Science Springer Journals

Demand-side decarbonization and electrification: EMF 35 JMIP study

Download PDF
16 pages

Loading next page...
 
/lp/springer-journals/demand-side-decarbonization-and-electrification-emf-35-jmip-study-rI7tsnpjtv

References (55)

Publisher
Springer Journals
Copyright
Copyright © The Author(s) 2021
ISSN
1862-4065
eISSN
1862-4057
DOI
10.1007/s11625-021-00935-w
Publisher site
See Article on Publisher Site

Abstract

Japan’s long-term strategy submitted to the United Nations Framework Convention on Climate Change emphasizes the importance of improving the electrification rates to reducing GHG emissions. Using the five models participating in Energy Modeling Forum 35 Japan Model Intercomparison project (JMIP), we focused on the demand-side decarbonization and analyzed the final energy composition required to achieve 80% reductions in GHGs by 2050 in Japan. The model results show that the electricity share in final energy use (electrification rate) needs to reach 37–66% in 2050 (26% in 2010) to achieve the emissions reduction of 80%. The electrification rate increases mainly due to switching from fossil fuel end-use technologies (i.e. oil water heater, oil stove and combustion-engine vehicles) to electricity end-use technologies (i.e. heat pump water heater and electric vehicles). The electricity consumption in 2050 other than AIM/Hub ranged between 840 and 1260 TWh (AIM/Hub: 1950TWh), which is comparable to the level seen in the last 10 years (950–1035 TWh). The pace at which electrification rate must be increased is a challenge. The model results suggest to increase the electrification pace to 0.46–1.58%/yr from 2030 to 2050. Neither the past electrification pace (0.30%/year from 1990 to 2010) nor the outlook of the Ministry of Economy, Trade and Industry (0.15%/year from 2010 to 2030) is enough to reach the suggested electrifica- tion rates in 2050. Therefore, more concrete measures to accelerate dissemination of electricity end-use technologies across all sectors need to be established. Keywords Demand-side decarbonization · Electrification · Multi-model scenario analysis Introduction Background Under the Paris Agreement, Japan pledged to reduce its greenhouse gas (GHG) emissions by 26% by 2030 from the Handled by Kenichi Wada, Research Institute of Innovative Technology for the Earth, Japan. * Shogo Sakamoto National Institute for Environmental Studies, 16-2 Onogawa, sakshogo@criepi.denken.or.jp Tsukuba, Ibaraki 305-8506, Japan Institute of Applied Energy, 1-14-2 Nishi-Shimbashi, Minato, Environmental Science Research Laboratory, Central Tokyo 105-0003, Japan Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba 270-1194, Japan School of Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan Socio-Economic Research Center, Central Research Institute of Electric Power Industry, 1-6-1 Otemachi, Chiyoda-ku, Institute of Energy Economics, Kachidoki 1-chome, Tokyo 100-8126, Japan Chuo-ku, Tokyo 104-0054, Japan 3 9 Institute for Future Initiatives, The University of Tokyo, Institute for Global Environmental Strategies (IGES), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan 2108-11 Kamiyamaguchi, Hayama, Kanagawa 240-0115, Japan Graduate School of Engineering, Kyoto University, Kyoto daigaku-katsura, Nishikyo-ku, Kyoto 615-8530, Japan Vol.:(0123456789) 1 3 396 Sustainability Science (2021) 16:395–410 2013 levels and cut emissions by 80% by 2050 (Government Research questions and aims of Japan 2019). As of 2018, the GHG emissions stood at 1240 Mt-CO2e, and around 50% were direct emissions from As mentioned above, while Japan’s Nationally Deter- the demand-side (Industry 25%, Residential 5%, Commer- mined Contribution (NDC) proposes an increasing share cial 5%, and Transportation 18%) (Ministry of the Environ- of electricity in 2030, Japan’s mid-century strategy lacks ment 2020). a concrete level of electrification. The low-carbon vision The power sector is going through a major reform in from the Ministry of Environment and Japan’s long-term Japan, and a rapid deployment of renewable energy has been strategy also do not reveal quantitative electrification path- contributing to supply-side decarbonization. In parallel with ways through 2050. Therefore; this study examines 2050 supply-side actions, it is also crucial to promote demand- low-carbon scenarios more concretely, with a focus on side decarbonization (Luderer et  al. 2018; Duscha et  al. electrification pathways. 2019). Sugiyama et al. (2019) shows that the demand-side, There are two dimensions that deserve detailed especially the industry sector, has the difficulty of achieving examination. emissions reductions in Japan’s energy system. First, how high and fast should the share of electricity Energy efficiency improvements are the first and useful increase in the midst of competition from other clean energy contributions in reducing emissions (Fujimori et al. 2014; carriers? Where and how much electrification contributes Sugiyama et al. 2014; Wakiyama and Kuramochi 2017), but to mitigation needs to be assessed, as electricity is not the switching the demand-side to clean energy carriers (electric- only clean energy carrier, and the role of electricity would ity, hydrogen, and bioenergy) is equally important (Deep be different by sectors. Oshiro et al. (2017) shows that for Decarbonization Pathways Project 2015; Ozawa et al. 2018; Japan to achieve an 80% emissions reduction in 2050, it is Matsuo et al. 2018; Gambhir et al. 2019; Wachsmuth and necessary to accelerate the pace of electrification and reach Duscha 2019). In fact, the Government of Japan has intro- the electrification rate of 45% in 2050. However, the long- duced electrification as one of the key policy areas along term energy demand and supply outlook by the Ministry with increasing use of bioenergy and hydrogen (Government of Economy, Trade and Industry (hereinafter called METI of Japan 2019). outlook), which is consistent with Japan’s NDC, shows the Notably, among clean energy carriers, numerous studies share of electricity in final energy (electrification rate) in show that a transition to electricity by the demand-side plays 2030 to be 29%, a mere 3% increase from 2013. a pivotal role in large-scale C O reduction of all demand Second, would decarbonization increase the total sectors on a global, national and urban scale (Sugiyama demand for electricity? Increasing the electrification rate 2012; Williams et al. 2012; Wei et al. 2013, Intergovern- and decreasing the fossil fuel consumption is an effective mental Panel on Climate Change (IPCC) 2014; Quiggin and way to reducing demand-side emissions. However, increas- Buswell 2016; Raghavan et al. 2017; IPCC 2018; Fortes ing the electrification rate does not automatically increase et  al. 2019; Hill et al. 2019; Luh et al. 2020; Zhang and its absolute demand. Sugiyama (2012) reviewed global Fujimori 2020). decarbonization pathways and found the electrification rate Electrification has been incorporated in Japan’s long-term to increase with more stringent emissions targets, but the energy plans. The long-term low-carbon vision (Ministry of absolute demand of electricity did not always increase. the Environment 2016), an input from the Ministry of the These two aspects are both dependent on a number of Environment to the policy debate on the long-term strategy, scenario assumptions as well as models. This study employs listed electrification, including a switch from combustion- the multi-model analytic framework of Energy Modeling engine vehicles to electric vehicles and diffusion of heat Forum (EMF) 35 Japan Model Intercomparison Project pumps for space and water heating, as one of the three pillars (JMIP) and characterizes future electrification pathways for to achieve low-carbon society in Japan. The 2019 long-term Japan to achieve the long-term emissions reduction goals. In strategy submitted by Japan to the United Nations Frame- particular, the present paper takes advantage of a framework work Convention on Climate Change also emphasizes the that includes various power supply technologies scenarios. need to increase electrification rates for 2050. Oshiro et al. (2019) is a notable study in a multi-model In contrast to the policy directions, there are only a few framework which focused on a Japan’s in-depth decar- concrete policies on electrification and most of them have bonization scenario. Although the study shows the share been subsidies or RD&D projects (Government of Japan of clean energy carriers grows in final energy use, elec- 2019). One can contrast this with more drastic measures trification pace, supply-side technology uncertainty, nor such as a ban on ICE cars in the United Kingdom (Govern- the total demand for electricity are analyzed. The present ment of UK 2017) and a proposal of a ban on the use of study attempts to fill the gap by finding a common pattern natural gas in the buildings (Deason and Borgeson 2019) in among results of multiple models of different types to draw a the west coast of the United States of America. 1 3 Sustainability Science (2021) 16:395–410 397 Table 1 Final energy carriers Sector Model Final energy carriers reported by each model b c d Electricity Gases Liquids Solids Hydrogen Other all Heat Solar Other Overall AIM/Enduse X X X X X X X X AIM/Hub X X X X X DNE21 X X X X IEEJ X X X X X X TIMES-Japan X X X X X X X X Industry AIM/Enduse X X X X X AIM/Hub X X X X IEEJ X X X X X X TIMES-Japan X X X X X X X X Residenital AIM/Enduse X X X X X X X AIM/Hub X X X X X IEEJ X X X X X TIMES-Japan X X X X X X X X Commercial AIM/Enduse X X X X X X X X AIM/Hub X X X X X IEEJ X X X X X TIMES-Japan X X X X X X X X Transportation AIM/Enduse X X X AIM/Hub X X X X IEEJ X X X X TIMES-Japan X X X X X Variables that are not reported can be represented in the model. When calculating the emissions, the differ - ence in emissions factors of petroleum, gas, biofuel, etc. is properly taken into consideration In DNE21, demand sector is not modeled separately Gases include natural gas, biogas, coal–gas, excluding transmission/distribution losses Liquids include conventional & unconventional oil, biofuels, coal-to-liquids, gas-to-liquids Solids include coal and solid biomass general conclusion related to the role of electricity in decar- considering numerous detailed technological representation bonizing the demand sector of Japan. in both energy supply and demand sectors, and the latter is a general equilibrium model with relatively aggregated tech- nological resolution but can consider the macroeconomic Methods responses considering the sectoral input–output changes in detail. DNE21, IEEJ and TIMES-Japan are perfect foresight Model description models. Only AIM/Hub is a general equilibrium model, and others are partial equilibrium models. This study employs scenarios from five energy-economic Since energy demand representation is much more het- and integrated assessment models: AIM/Enduse-Japan erogeneous across models than supply-side structures, it is (Oshiro and Masui 2015; Fujimori et al. 2019; Kainuma favorable to have an overview of the decomposition of sec- et al. 2003), AIM/Hub-Japan (Fujimori et al. 2017a, b, c; tors and the inclusion of different final energy carriers. The Silva et al. 2019), DNE21 (Hosoya and Fujii 2011; Fujii and reason for different model behaviors could be attributable to Komiyama 2015), IEEJ_Japan 2017 (Matsuo et al. 2013, which final energy carrier is explicitly represented. 2020), and TIMES-Japan (Kato and Kurosawa 2019; Kuro- Table 1 clarifies final energy carriers by sectors reported sawa and Hagiwara 2012; Loulou et al. 2005; Sato 2005). by the participating models. Electricity is included in all Hereafter, each model is called AIM/Enduse, AIM/Hub, models while hydrogen is represented in AIM/Enduse, IEEJ, DNE21, IEEJ, and TIMES-Japan. AIM/Enduse and AIM/ and TIMES-Japan. Some models do not report biomass- Hub are recursive dynamic models. The former is a typical related carrier (solids biomass, biofuels, and biogas) sepa- energy system model that minimizes total energy system cost rately. These carriers are reported in an aggregated manner 1 3 398 Sustainability Science (2021) 16:395–410 and included in the corresponded carriers (solids, liquids, 26by30 + 80by50_NoCCS: CCS is completely unavail- able. and gases). Note that DNE21 does not explicitly represent energy services by sectors; instead, their demands are rep- In the 26by30 + 80by50_LoVREcost, VRE’s capital cost resented as fuel demands. Also, AIM/Hub does not repre- sent energy services, yet fuel demands are represented for was halved compared to 26by30 + 80by50_Def, but the mod- els did not harmonize the timing of the cost change. Hereaf- each sector. Detailed end-use technologies by models are shown in ESM (Table ESM1 to 4). The more detailed model ter, the scenario prefix “26by30 + 80by50_” is dropped for sensitivity scenarios in this paper for brevity in reporting. descriptions are provided in Sugiyama et al. (2021). We also examine different levels of emissions con- straints. More stringent emissions constraint should accel- Scenarios erate demand-side decarbonization, resulting in higher clean energy carrier shares or electrification rates (Fortes et al. We briefly describe the salient aspects of the scenarios that are analyzed in this paper (see Sugiyama et al. 2021 for 2019). Targeting 2050, we consider 70%, 80%, 90%, and 100% emission reduction levels to understand the impacts fuller descriptions). The central scenario is a mitigation scenario that of climate policies. In addition to 26by30 + 80by50_Def, we explore following scenarios: is consistent with the NDC and mid-century strategy (26by30 + 80by50_Def). The “Baseline” scenario is a sce- 26by30 + 70by50_Def; nario with no climate policy. We also consider an extensive list of sensitivity runs 26by30 + 90by50_Def; and 26by30 + 100by50_Def. on variable renewables (VREs) and nuclear generation. It is now well established that the power sector needs to go In the JMIP study, not all participating models have 90% through almost a complete decarbonization in the long run (IPCC 2014, 2018). Cheap clean electricity makes electri- and 100% C O emissions reduction scenarios in 2050. In AIM/Enduse, 26by30 + 100by50_Def is infeasible, and fication economically competitive, and can further promote demand-side electrification (Zhang et al. 2012). However, in IEEJ and TIMES-Japan, 26by30 + 90by50_Def and 26by30 + 100by50_Def are infeasible. Therefore; pathways the availability of affordable clean electricity depends on multiple technological parameters. It is therefore useful to to achieve net carbon neutrality, a new pledge presented by Prime Minister Suga in October 2020 (Prime Minister’s examine the impact of supply-side sensitivities on demand- side electrification. Office of Japan 2020), could not be elaborated in this paper. This is a future research issue. The JMIP study also explores a scenario regarding the availability of Carbon Capture and Storage (CCS) in addi- tion to VREs and nuclear power generation technology. Since CCS can be deployed both in the power generation Results sector and the industry sector, it can be a crucial technology to decrease demand-side emissions.Overall CO emissions and final energy use in 2050 This paper considers the following scenarios: The CO emissions in 2050 for the 26by30 + 80by50_Def • scenario are around 280Mt-CO (237–336Mt-CO ). The 26by30 + 80by50_LoVREcost: halving the costs of 2 2 VREs; supply side sees a sharp reduction to which the emissions are • less than 100Mt-CO in all models. However, the demand 26by30 + 80by50_HiVREcost: doubling the costs of VREs; sector still emits approximately 200Mt-CO (199–252Mt- • CO ) (see Figure ESM 1.) showing that the demand-side 26by30 + 80by50_LoVREpot: Resource potential for wind and solar halved for 2020 and onwards; reduction is crucial in achieving emissions reduction tar- • gets. The total amount of CO captured and stored is around 26by30 + 80by50_HiVREpot: Resource potential for wind and solar doubled for 2020 and onwards; and 160Mt-CO (23–350Mt-CO ), of which around 40 Mt-CO 2 2 2 • (0–109Mt-CO ) is captured in the demand sector (the indus- 26by30 + 80by50_NoNuc: nuclear power is completely unavailable. try sector, including industrial processes). Since the mid-century strategy does not specify the base year, the base year used to calculate 80% reduction differs among models (2010 in AIM/Enduse, 2005 in AIM/Hub, 2000 in DNE 21, 2013 in IEEJ, and 2013 in TIMES-Japan). 1 3 Sustainability Science (2021) 16:395–410 399 Fig. 1 Final energy use in 2010 and 2050 by fuels in 26by30 + 80by50_Def: a Final energy use in 2010 and 2050, b Difference in final energy use 2010 and 2050, c Fuel share in final energy use in 2010 and 2050, and d Difference of fuel share in final energy use 2010 and 2050 Next, we present final energy (reported in lower heat- hydrogen and gases, see different patterns depending on ing value) by fuel types in 2010 and 2050 for the models. 26by30 + 80by50_Def scenario (Fig. 1). One common trend All models show a substantial decrease in the final energy among the models is a drastic decrease in liquids, mostly oil use from 2010 to 2050. The net final energy use decreases products, by 4.1EJ to 5.5EJ compared to 2010 (the reduction by 5EJ in AIM/Enduse and by 7EJ in IEEJ. Despite simi- rate ranges from 44 to 78%). A similar trend of decreasing lar reduction in liquids and solids, the net final energy consumption is observed in solids, which sees a decrease by use only decreases around 4EJ in AIM/Hub, DNE21, and about 1EJ in all models. Other energy carriers, electricity, TIMES-Japan due to the increasing use of electricity, gas and hydrogen. In AIM/Enduse, most fuels are reduced with only a slight increase in hydrogen and “other all (heat, solar, and other sources)”. In IEEJ, only a slight increase in hydrogen There is a discrepancy in the final energy use in 2010, the base is seen and significant energy savings in all other fuels. In year, as the participating models use different databases and have dif- AIM/Hub, DNE21, and TIMES-Japan electricity, gas and ferent industry sector representation (see Sugiyama et al. 2021). 1 3 400 Sustainability Science (2021) 16:395–410 Fig. 2 CO emissions and CO 2 2 reduction rate by demand-side sectors in 26by30 + 80by50_ Def: a CO emissions in 2010 and 2050, and b CO reduction rate in 2050 from 2010. Note: DNE21 does not report CO emissions by sectors hydrogen increase while fossil fuel consumption reduces. In CO emissions and final energy use by sectors AIM/Hub, a significant increase in electricity consumption in 2050 is observed. In DNE21, electricity and gases increase. In TIMES-Japan, electricity, gases, and hydrogen significantly The overall direct CO emissions reduction rate of the increase. demand-side from 2010 to 2050 is approximately 70%, but The electricity demand stays at a relatively the same the reduction rates by sectors vary across models as shown level compared to the current consumption, 3.0–4.5EJ in Fig. 2. The CO emissions reduction rates are 50–84% in (840–1260TWh), with one exception of AIM/Hub which the industry sector including industrial processes, 36–82% sees a sharp increase to 7.0EJ (1950TWh) in 2050. In terms in the residential sector, 34–100% in the commercial sector, of the absolute electricity demand, both results of increasing and 54–93% in the transportation sector. and decreasing were seen among models, which is consist- The CO emissions in the transportation sector are the ent with the findings of Sugiyama (2012). Despite the level smallest in AIM/Enduse while they are the largest in AIM/ of consumption staying relatively flat in 2050, the electri- Hub. Both in IEEJ and TIMES-Japan, the largest emitting fication rate increases in all models (AIM/Enduse: 37%; sector is the industry sector and the smallest is the com- AIM/Hub: 66%; DNE21: 39%; IEEJ: 44%; TIMES: 43%) mercial sector. However, in IEEJ, the C O emissions of the compared to around 26% in 2010 as the total final energy residential sector is about half of the transportation sector, use decreases. The electrification rates increase at a pace of but in TIMES-Japan, the residential sector and the transpor- 0.03–0.45%/year from 2010 to 2030, but increase at a faster tation sector have almost the same CO emissions. pace of 0.46–1.58%/year from 2030 to 2050. The variation among models is caused by the differences With regards to other clean energy carriers, a notable in final energy use changes in each sector from 2010 to 2050. increase in hydrogen is seen in IEEJ and TIMES-Japan mod- Figure 3. shows the differences among models in the final els, providing around 10% of final energy in 2050 (AIM/Hub energy use by fuels in industry, residential, commercial, and and DNE21 have no hydrogen option). transportation sectors in 2010 and 2050. The industry sec- tor continues to be the most consuming sector in all models despite the largest decrease in the final energy use among all sectors in most models. The transport sector goes through a rapid transition with a rapid decline in use of liquids (mostly AIM/Hub’s large increase in the electricity consumption is con- oil products). tributed to the way demands are determined. AIM/Hub is the only The final energy use in the industry sector in 2050 ranges general equilibrium model within this comparison, which determines between 3.3 and 5.7EJ, and the electricity consumption energy use by CES (Constant-Elasticity-of Substitution) function rather than energy services. ranges between 0.8 and 2.5EJ. The share of final energy 1 3 Sustainability Science (2021) 16:395–410 401 Fig. 3 Final energy use by fuel type by sector in 2010 and 2050 in e Final energy use in commercial sector in 2010 and 2050, f Differ - 26by30 + 80by50_Def: a Final energy use in industry sector in 2010 ence in final energy use 2010 and 2050 in commercial sector, g Final and 2050, b Difference in final energy use 2010 and 2050 in indus- energy use in transportation sector in 2010 and 2050, and h Differ - try sector, c Final energy use in residential sector in 2010 and 2050, ence in final energy use 2010 and 2050 in transportation sector d Difference in final energy use 2010 and 2050 in residential sector, use by the industry sector in 2050 is 32–60%, close to half up most of the demand. The reduction in liquids demand in three models. The industry sector transforms its energy is a major movement in the residential sector as the liquids composition largely dependent on liquids and solids (around demand decreases to less than 0.1EJ in three models, imply- 60% in all models) in 2010 to delivering half of its energy ing that oil water heater and stoves are virtually phased out from electricity, gases and hydrogen in 2050. Although the in the residential sector (Oshiro and Fujimori 2020). Most largest reduction is seen in liquids, the consumption of liq- models see a decrease in the final energy demand, but AIM/ uids still stays high around 1.2EJ in all models. Solids are Hub sees an increase as the increase in electricity demand also reduced in all models, but most models still use around surpasses the decrease in liquids demand. 0.6EJ in 2050. The final energy use in the commercial sector in 2050 The final energy use in the residential sector ranges is 1.3–2.4EJ, of which electricity is the major energy car- between 1.2 and 2.4EJ of which gases and electricity make rier. The use of liquids and gases are greatly reduced and 1 3 402 Sustainability Science (2021) 16:395–410 Fig. 4 Share of fuels in final energy by sectors in 2010 and 2050 in 26by30 + 80by50_Def: a Industry sector, b Residential sector, c Commercial sector, and d Transportation sector almost no longer consumed (0–0.02EJ for liquids, 0–0.2EJ electrification rates is attributed also to the increasing con- for gases) except for AIM/Enduse which has a relatively sumption of electricity along with decreasing consumption large CO emissions in the commercial sector. This implies of other fuels (see also Fig. 3). that nearly all oil and gas appliances (mainly cooking, water In the industry sector, the electrification rate stays the heater, and space heating) needs to be phased out in this sec- lowest among sectors at around 20%, an increase of only a tor to reach emissions reduction targets. few percentage points from 2010. One exception is the AIM/ The transportation sector sees a rapid transformation from Hub (the only participating GE model), in which rapid elec- heavily liquids dependent energy composition to a more trification takes place up to 73% in 2050.In the residential mixed composition. Other than AIM/Hub, which does not sector, the electrification rate is the highest among all fuels model hydrogen, models see an increase in both electric- in all models (46–75%), showing the importance in elec- ity and hydrogen. The electricity consumption increases to trifying the residential end-use technologies. On the other 0.3–0.6EJ, whereas the hydrogen consumption increases to hand, the share of liquids (mostly oil products) decrease sig- 0.1–0.6EJ. Since most of the energy use in the transporta- nificantly suggesting a need to initiating a phase out of oil tion sector was oil products in 2010, liquids consumption water heater and stoves. The commercial sector, which has decreases by 1.3–2.5EJ. The replacing technologies (elec- the highest electrification rate across sectors in all models tric vehicles and hydrogen vehicles) typically have higher (62–95%), sees the use of liquids disappear in three models efficiency, so the final energy use in the sector reduces to implying limited use of oil and gas appliances (mainly for 1.0–2.4EJ. The share of transportation sector in overall final cooking, hot water, and space heating) in a decarbonized energy, which was around 25% in 2010, decreases to around society. The transport sector sees a great increase in the 15% in most models. share of electricity. In 2010 the share is very low at around Figure 4 shows fuel share of final energy use by sectors 2%, but it increases to 20–40% in models. in 2010 and 2050. Two trends observed in all sectors from As a complement, the share of hydrogen, a clean 2010 to 2050 are the decrease in the share of liquids and the energy carrier competing with electricity, is described increase in electrification rates (with the exception of the by sector. In the industry sector, hydrogen is introduced residential sector’s electricity share in the AIM/Enduse). The in 2050 with a share of 9% and 7% in IEEJ and TIMES- electrification rates increase mainly due to decreasing con- Japan respectively, while the electrification rates reach sumption of other fuels in the industry and residential sec- 23% and 29%. Likewise, in the transport sector, both tors. In the commercial and transport sectors, the increasing electricity and hydrogen are introduced in 2050. In AIM/ 1 3 Sustainability Science (2021) 16:395–410 403 Fig. 5 Carbon intensity in 2010 and 2050 and relationship to elec- electrification rate and carbon intensity by sector in 2050. Note: Car - trification rate by sector in 2050 in 26by30 + 80by50_Def: a Carbon bon intensity calculates by only direct emissions without CCS in intensity by sector in 2010 and 2050, and b The relationship between industry sector Enduse, electricity is 20% while hydrogen is 7% and in Sensitivity analysis IEEJ, electricity is 24%, hydrogen is 19%. In TIMES- Japan, the share of hydrogen is higher than electricity, VREs and nuclear generation sensitivity with electricity at 40% while hydrogen at 44%. Carbon intensity (the emission amount per unit final In order to analyze the effects of available VREs and nuclear energy use) is reduced across all models in 2050. Look- generation, scenarios with high and low VRE costs, high ing at the C O emissions (Fig. 2) and the final energy use and low VRE resource potential, and no nuclear (LoVRE- (Fig.  3) in each sector from 2010 to 2050, the demand cost, HiVREcost, HiVREpot, LoVREpot, and NoNuc) are sector’s carbon intensities in 2010 is 48–56 g-CO /MJ, compared. Figure 6 shows the share of energy carriers in but they are reduced to 22–29 g-CO /MJ in 2050 (Fig. 5). each scenario by models. Although electrification rates are The lowest carbon intensity is seen in the commercial sec- different in each model, all models maintain electrification tor (0–22 g-CO /MJ), followed by the residential sector rates close to the level of 26by30 + 80by50_Def scenario (11–28 g-CO /MJ). The model average of carbon inten- as the change ranges between − 4.3 and + 6.5%pt (see also sity in the industry sector including industrial processes Figure ESM3). (28 g-CO /MJ) and the transportation sector (30 g-CO / A notable change in the share of n fi al energy is seen in the 2 2 MJ) remain to be high-emitting sectors. following scenarios. AIM/Enduse shows a higher electrifi - The carbon intensity strongly depends on the ratio of cation rate (+ 1.2%pt) in the HiVREcost scenario than the fuel types in the final energy use. The value of carbon 26by30 + 80by50_Def scenario because the electricity con- intensity increases as the share of fossil fuels increases, sumption is slightly higher (+ 0.01EJ) while the final energy and the carbon intensity decreases as the share of use decreases by 0.24EJ. In AIM/Hub, the electrification rate clean energy carriers, such as electricity and hydrogen, decreases from the 26by30 + 80by50_Def scenario in the increase. Therefore, sectors with high electrification rates HiVREcost (− 4.3%pt) and the NoNuc (− 2.2%pt) scenarios have low-carbon intensities as shown in Fig. 5 and con- by increasing liquids consumption, while the electrification tribute greatly in reducing the demand-side emissions. rate increases from the 26by30 + 80by50_Def scenario in the 1 3 404 Sustainability Science (2021) 16:395–410 Fig. 6 Final energy mix in 2050 in VREs and nuclear generation sensitivity scenarios LoVREcost (+ 4.5%pt) and the HiVREpot (2.1%pt) scenar- Models maintain electrification rates close to the level of ios by decreasing liquids consumption. In DNE21, only the 26by30 + 80by50_Def scenario as the change ranges only NoNuc scenario shows a slight decrease in the electrification between − 0.2 and + 1.8%pt. One exception is AIM/Enduse, rate (− 0.2%pt) from 26by30 + 80by50_Def because DNE21 which sees a notable increase of 8.8%pt as over 100Mt of has a high share of nuclear power generation due to no quan- CCS is deployed on the demand side (around 110Mt-CO tity constraint (see Shiraki et al. 2021) in 26by30 + 80by50_ in the industry sector including industrial processes) in Def. IEEJ and TIMES-Japan models show a competitive 26by30 + 80by50_Def. When CCS is not available, AIM/ nature between VRE and hydrogen. Hydrogen consumption Enduse decreases gas consumption and increases electricity decreases when more VREs electricity becomes accessible demand to reduce CO emissions in the residential and com- (LoVREcost and HiVREpot), while hydrogen consumption mercial sectors to compensate for the increasing emissions increases when electricity from VREs and nuclear becomes in the industry sector. limited (HiVREcost, LoVREpot and NoNuc). The electrification rate correlates positively with the Emissions policy sensitivity availability of VREs and nuclear power sources, but the cases considered in this modeling exercise were not enough Figure 8 shows the changes in the share of final energy carri- to change the electrification rates drastically. When avail- ers when the emission reduction target for 2050 is 70%, 80%, ability of nuclear is restricted, VRE replaced the genera- 90%, and 100% (26by30 + 70by50_Def, 26by30 + 80by50_ tion and vice versa. In summary, the cost and availability of Def, 26by30 + 90by50_Def, and 26by30 + 100by50_Def). VREs and nuclear generation does not change the need for Some models were not able to provide results as the emis- electrifying the demand sector to achieve the 80% reduction sions policy became extremely stringent. (26by30 + 90by50_ in 2050. Def: IEEJ, TIMES-Japan; 26by30 + 100by50_Def: AIM/ Enduse, IEEJ and TIMES-Japan). CCS sensitivity When a stricter emissions reduction policy is applied, the electrification rates increase in all models (Fig.  9), show- Figure  7 shows the share of final energy carriers and ing the importance of electricity as a clean energy carrier CO emissions in the NoCCS scenario by models. in the demand sector. Electricity typically replaces gases 1 3 Sustainability Science (2021) 16:395–410 405 Fig. 7 Final energy use and C O emissions in 2050 in CCS sensitivity scenario: a Final energy use and b CO emissions (26by30 + 80by50_Def 2 2 and 26by30 + 80by50_NoCCS). Note: DNE21 does not report CO emissions by sectors. DNE21 are not classified and liquids, but in some models (DNE21, IEEJ) the gases In DNE21, the electricity consumption stays the same consumption increases with tighter emissions targets. An from 70 to 90% reduction targets at 4.5EJ (1260TWh) but increase in hydrogen consumption with tighter emissions increases to 4.7EJ (1300TWh) in 100% reduction target. targets is also observed in AIM/Enduse, IEEJ and TIMES- The consumption of liquid decreases from 6.6 to 2.3EJ as Japan, all the models with a hydrogen option. the emission target gets tighter from 70 to 100% as in all In AIM/Enduse, electricity consumption increases from models, but the consumption of gases increases from 1.8 3.1 to 3.7EJ (860–1030TWh) as the emissions target gets to2.7EJ. tighter from 70 to 90%. The biggest reduction seen is in In IEEJ, the electricity consumption increases from 2.9 gases as the consumption decreases from 2.0 to 0.9EJ fol- to 3.0EJ (820–830TWh) as the emissions target gets tighter lowed by liquids from 2.3 to 1.9EJ. from 70 to 80%. The coal and liquids demand decrease as in AIM/Hub’s electricity consumption increases from 6.5 to other models, but the biggest increase is seen in hydrogen 7.8EJ (1800–2160TWh) as the emissions target gets tighter which increases from close to zero to 0.5EJ. from 70 to 100%. The increase in the electricity consump- tion replaces gases and liquids as the gases decrease from 0.8 to 0.1EJ, and liquids decrease from 4.4 to 1.0EJ. 1 3 406 Sustainability Science (2021) 16:395–410 Fig. 8 Final energy use by fuel type in 2050 in emissions policy scenarios Discussion Electrification pace and METI outlook The METI outlook assumes the final energy use in 2030 to be reduced by 14% (14.4–12.4EJ) while the electricity consumption to be reduced by only 5% (3.7–3.5EJ) com- pared to 2010. Since the final energy reduction rate is higher, the METI outlook recommends electrification rate to be increased from 26 to 29% or the electrification rate to increase at the pace of 0.15%/year. The electricity rate in Japan has increased from 13% in 1970 to 28% in 2018. Looking at a 20-years span, the annual percent change in electrification has been 0.37%/year from 1970 to 1990, and 0.30%/year from 1990 to 2010. Since 2011 the pace of electrification has slowed down to 0.18%/ Fig. 9 Electrification rate and emissions reduction targets in 2050 year from 2010 to 2018. In the 26by30 + 80by50_Def scenario, the electrification In TIMES-Japan, the electricity consumption increases rates increase at a pace of 0.03–0.45%/year from 2010 to from 3.9 to 4.1EJ (1090–1130Wh) as the emissions tar- 2030, showing that the historical rates and the rate assumed get gets tighter from 70 to 80%. Like IEEJ, the TIMES- by METI outlook could be enough to reach the 2030 target Japan sees a decrease in liquids and gases while hydrogen (Fig. 10). However, as mentioned in the results section, the increases the most from 0.3 to 1.2EJ. electrification pace must be accelerated from 2030 to 2050 and need to reach the range of 0.46–1.58%/year. This pace is 1.5–5.3 times higher than the historical average of 0.30%/ year (199–2010), a period of relatively electrification leading 1 3 Sustainability Science (2021) 16:395–410 407 Fig. 10 Electrification rate from 1980 to 2050 in Historical, Baseline and 26by30 + 80by50_Def: a Electrification rate from 1980 to 2050, b Electrification rate in 2030 and 2050, and c Average of annual change in electrification rate from 2010 to 2030 and 2030 to 2050 up to the 2011 Tohoku earthquake and tsunami. Taking into that the electrification pace needs to be increased. While consideration that the pace of electrification in the baseline there are variations in the electric fi ation rates and electricity scenario, a scenario without a climate policy, is 0.14–0.49%/ demand by sectors among models, a common trend in end- year from 2030 to 2050 in the 26by30 + 80by50_Def in use technology was observed in the residential, commercial 2050, increasing electrification rates to achieve 80% reduc- and transportation sectors. The use of oil water heater and tion in 2050 will require additional policy measures. Mul- stoves decreases in the residential sector and gas appliances tiple studies (Seto et al. 2016; Unruh 2000) have pointed decreases in the commercial sector. In the transportation sec- out that a lock-in mechanism could delay the diffusion of tor, fossil fuel vehicles decreased significantly, while they technologies. Policies and measures to alleviating the lock-in were replaced by electric and fuel cell vehicles. There is mechanism which can delay electrification need be consid- a big difference among models in terms of the timing and ered to increase the pace of electrification suggested by the pace of electrification by sectors, but there is a clear conclu - models to achieve the emissions reduction target. Policy- sion that the overall electrification rate of the demand sector makers could refer to some advanced electrification meas- needs to be increased. A detailed analysis of the differences ures recently taken to decarbonize buildings by several US between the models of electrification pace by sector is a states. The measures include obligation or recommendation topic for the future. Since Ju et al. (2021) reports results of to electrify new buildings, installation assistance for electri- energy use in the industry sector in details from the same cal equipment, the requirement for electrification ready, and Model Intercomparison project. providing consumers with information on benefits such as It is also important to note that reducing emission comfort and controllability of electrical equipment (Nishio intensity of electricity is a prerequisite for mitigation and Nakano 2020). through electrification (Zhang and Fujimori 2020). In the Looking further into the sectoral electrification rates, 26by30 + 80by50_Def scenario, the model results show the there is no consensus among the models on the pace of elec- emission intensity of electricity sharply decreases from 2040 trification. Only in the transportation sector alone, which to 2050, but a lock-in mechanism also applies to the supply currently has a very low electrification rate, all models show sector. Along with accelerating the pace of electrification, 1 3 408 Sustainability Science (2021) 16:395–410 the emission intensity of electricity should be reduced as zero emissions in 2050, it is necessary to consider the role accordingly from an early stage. of biomass together with hydrogen in the future analysis of electrification. Electricity and hydrogen The two clean energy carriers introduced with a notable Conclusion share in 2050 in this modeling comparison exercise are elec- tricity and hydrogen. In two models in which hydrogen is not In this study, we analyzed the change in energy use structure modeled, AIM/Hub and DNE21, electricity is chosen as the of the demand sector in scenarios achieving 80% reduction clean energy carrier. In other three models (AIM/Enduse, in 2050, Japan’s long-term reduction target, focusing on the IEEJ and TIMES-Japan), hydrogen is introduced along with role of electricity. electricity to decarbonize the demand sectors. Hydrogen is In order to achieve the long-term reduction target, it is mainly introduced in the industry and transportation sectors, necessary to significantly reduce CO emissions not only as hydrogen is a good option for hard to electrify demands in the supply side but also in the demand side. The model such as high temperature industrial heat demands, heavy results of the scenario that is consistent with the NDC and trucks and ships. The residential and commercial sectors mid-century strategy show approximately 70% reductions also have limited end-use technologies options available for in the demand-side emissions in this modeling comparison. hydrogen. The reduction is contributed to a significant reduction in the If we turn to the supply side, typically hydrogen is pro- final energy use, especially fossil fuels, while maintaining or duced by electrolysis of water using carbon free electric- increasing consumption of low emission intensity electricity. ity (International Energy Agency 2019), so the domestic The electrification rate increases mainly due to switching hydrogen production is directly related to an increase in the from fossil fuel end-use technologies (i.e. oil water heater, supply-side electricity generation, not electricity demand oil stove and combustion-engine vehicles) to electricity end- in the demand sectors (see Figure ESM 4). In TIMES- use technologies (i.e. heat pump water heater and electric Japan, the electricity generation jumps to nearly 2000TWh vehicles). in the HiVREpot scenario compared to 1350TWh in the The pace at which electrification rate must be increased 26by30 + 80by50_Def scenario (Note that electricity con- is a challenge. Electrification has been advancing as a trend, sumption in Fig.  6 does not include the electricity con- but neither the past electrification pace nor the outlook of sumption for hydrogen production, which is categorized as the Ministry of Economy, Trade and Industry is enough to secondary energy use), as hydrogen is produced domesti- reach the suggested electrification rate of 37–66% suggested cally using more readily available wind and solar. Such an by the models in 2050. Therefore, a more focus should be increase in the amount of power generated for hydrogen given on demand side electrification in the long-term strat- production is regarded as indirect electrification. For exam- egy, and more concrete measures, such as banning the sale ple, net zero emissions scenario of the UK Committee on of combustion-engine vehicles by UK or requiring building Climate Change (2019) and Capros et al. (2019) explicitly electrification as in Berkeley, to accelerate dissemination of takes into account that the amount of electricity required electricity end-use technologies across all sectors need to for electrolysis of water will occur at a level comparable to be established. the electricity demand of the traditional demand sector. It is also possible to import hydrogen; in which case the domestic Supplementary Information The online version contains supplemen- electricity generation is not affected. Such a case is IEEJ, in tary material available at https: //doi.org/10.1007/s11625 -021-00935- w. which all of hydrogen consumed in the model is imported. Acknowledgements This research was supported by the Environment Although METI outlook only explicitly considers elec- Research and Technology Development Fund 2-1704 of the Environ- tricity for the demand sector in 2030, hydrogen along with mental Restoration and Conservation Agency. KO was supported by electricity could play a vital role in the future energy mix. JSPS KAKENHI Grant Number JP20K14860 and the Environmental By 2050, innovation could open the possibility of afford- Research and Technology Development Fund (JPMEERF20201002) of the Environmental Restoration and Conservation Agency of Japan. SF able domestic hydrogen production options. Therefore, the and KO were supported by Sumitomo Foundation. SS was supported amount of electricity generation possibly required to pro- by the Integrated Research Program for Advancing Climate Models duce hydrogen should be carefully considered in the discus- (TOUGOU) Grant Number JPMXD0717935457 from the Ministry of sion for the energy mix of 2050, for example, in the revision Education, Culture, Sports, Science and Technology (MEXT), Japan. RK was supported by JSPS KAKENHI Grant Number JP20H02679 of the basic energy plan. and JP17H03531. DSH was supported by the Environmental Research We did not discuss the role of biomass, which is one of and Technology Development Fund (JPMEERF20201002) of the Envi- the low-carbon carriers, in this study. Since biomass could ronmental Restoration and Conservation Agency of Japan and by the play an important role in extreme reduction scenarios, such Strategic Operation Fund and the Strategic Research Fund of IGES. 1 3 Sustainability Science (2021) 16:395–410 409 Open Access This article is licensed under a Creative Commons Attri- Government of Japan (2019) The long-term strategy under the bution 4.0 International License, which permits use, sharing, adapta- paris agreement. https ://unfcc c.int/sites /defau lt/files /resou rce/ tion, distribution and reproduction in any medium or format, as long The%20Long-ter m%20Strategy %20und er%20t he%20P aris%20 as you give appropriate credit to the original author(s) and the source, Agr eemen t.pdf provide a link to the Creative Commons licence, and indicate if changes Government of UK (2017) UK plan for tackling roadside nitrogen were made. The images or other third party material in this article are dioxide concentrations. https ://asset s.publi shing .servi ce.gov. included in the article’s Creative Commons licence, unless indicated uk/go v er nment /uploa ds/sy s te m/uploa ds/att ac hment _dat a/ otherwise in a credit line to the material. If material is not included in file/63327 0/air-quali ty-plan-detai l.pdf the article’s Creative Commons licence and your intended use is not Hill G, Heidrich O, Creutzig F, Blythe P (2019) The role of elec- permitted by statutory regulation or exceeds the permitted use, you will tric vehicles in near-term mitigation pathways and achieving need to obtain permission directly from the copyright holder. To view a the UK’s carbon budget. Appl Energy 251:113111. https ://doi. copy of this licence, visit http://creativ ecommons .or g/licenses/b y/4.0/.org/10.1016/j.apene rgy.2019.04.107 Hosoya Y, Fujii Y (2011) Analysis of energy strategies to halve CO emissions by the year 2050 with a regionally disaggregated world energy model. Energy Procedia 4:5853–5860 References Intergovernmental Panel on Climate Change (2014) Climate Change 2014: Mitigation of Climate Change. Contribution of Working Capros P, Zazias G, Evangelopoulou S, Kannavou M, Fotiou T, Sis- Group III to the Fifth Assessment Report of the Intergovern- kos P, Vita A, Sakellaris K (2019) Energy-system modelling mental Panel on Climate Change, Cambridge University Press of the EU strategy towards climate-neutrality. Energy Policy Intergovernmental Panel on Climate Change (2018) Global Warm- 134:110960. https ://doi.org/10.1016/j.enpol .2019.11096 0 ing of 1.5 °C: An IPCC Special Report on the impacts of global Committee on Climate Change (2019) Net Zero – Technical Report. warming of 1.5 °C above pre-industrial levels and related global https://www .theccc.or g.uk/publicatio n/ne t-zero-technical-r epor greenhouse gas emissions pathways, in the context of strength- t/ ening the global response to the threat of climate change, sus- Deason J, Borgeson M (2019) Electrification of buildings: poten- tainable development, and efforts to eradicate poverty tial, challenges, and outlook. Curr Sustain Renew Energy Rep International Energy Agency (2019) The future of hydrogen. Seiz- 6:131–139. https ://doi.org/10.1007/s4051 8-019-00143 -2 ing today’s opportunities. https://www .iea.org/reports/t he-futur Deep Decarbonization Pathways Project (2015) Pathways to deep e-of-hydro gen Decarbonization 2015 synthesis report. https ://www.iddri .org/ Ju Y, Sugiyama M, Kato E et al (2021) Industrial decarbonization en/publi catio ns-and-event s/repor t/pathw ays-deep-decar boniz under Japan’s national mitigation scenarios: a multi-model anal- ation -2015-synth esis-repor t ysis. Sustain Sci. https ://doi.org/10.1007/s1162 5-021-00905 -2 Duscha V, Denishchenkova A, Jakob Wachsmuth J (2019) Achiev- Kainuma M, Matsuoka Y, Morita T (2003) Climate policy assess- ability of the Paris agreement targets in the EU: demand-side ment: Asia-Pacific integrated modeling. Springer, Tokyo reduction potentials in a carbon budget perspective. Clim Policy Kato E, Kurosawa A (2019) Evaluation of Japanese energy sys- 19(2):161–174. https ://doi.org/10.1080/14693 062.2018.14713 tem toward 2050 with TIMES-Japan—deep decarboniza- 85 tion pathways. Energy Procedia 158:4141–4146. https ://doi. Fortes P, Simoes S, Gouveia J, Seixas J (2019) Electricity, the silver org/10.1016/j.egypr o.2019.01.818 bullet for the deep decarbonisation of the energy system? Cost- Kurosawa A, Hagiwara N (2012) Long term energy system analysis effectiveness analysis for Portugal. Appl Energy 237:292–303. of Japan after March 11, 2011, 3rd IAEE Asian Conference, https ://doi.org/10.1016/j.apene rgy.2018.12.067 February 21. https://enek en.ieej.or .jp/3rd_IAEE_Asia/pdf/paper Fujii Y, Komiyama R (2015) Long-term energy and environmental /106p.pdf. [accessed 29 May 2020] strategies. In: Ahn J, Carson C, Jensen M, Juraku K, Nagasaki Loulou R, Remne U, Kanudia A, Lehtila A, Goldstein G (2005) S, Tanaka S (eds) Reflections on the Fukushima Daiichi nuclear Documentation for the TIMES model—part I. http://iea-etsap accident. Springer, pp 105–115.org/docs/TIMES Doc-Intro .pdf. [accessed 29 Apr 2020] Fujimori S, Kainuma M, Masui T, Hasegawa T, Dai H (2014) The Luderer G, Vrontisi Z, Bertram C, Edelenbosch OY, Pietzcker RC, effectiveness of energy service demand reduction: a scenario Rogelj J, De Boer HS, Drouet L, Emmerling J, Fricko O, Fuji- analysis of global climate change mitigation. Energy Policy mori S, Havlík P, Iyer G, Keramidas K, Kitous A, Pehl M, Krey 75:379–391. https ://doi.org/10.1016/j.enpol .2014.09.015 V, Riahi K, Saveyn B et al (2018) Residual fossil C O emissions Fujimori S, Hasegawa S, Masui T (2017a) AIM/CGE V2.0: basic in 15–2 °C pathways. Nat Clim Change 8(7):626–633. https :// feature of the model. In: Fujimori S, Kainuma M, Masui T doi.org/10.1038/s4155 8-018-0198-6 (eds) Post-2020 climate action global and Asian perspective. Luh S, Budinis S, Giarola S, Schmidt T, Hawkes A (2020) Long- Springer, pp 305–328 term development of the industrial sector—Case study about Fujimori S, Hasegawa T, Masui T, Takahashi K, Silva Herran D, Dai electrification, fuel switching, and CCS in the USA. Comput H, Hijioka Y, Kainuma M (2017b) SSP3: AIM implementa- Chem Eng 133:106602. https: //doi.org/10.1016/j.compc hemen tion of shared socioeconomic pathways. Glob Environ Chang g.2019.10660 2 42:268–283. https ://doi.org/10.1016/j.gloen vcha.2016.06.009 Matsuo Y, Endo S, Nagatomi Y, Shibata Y, Komiyama R, Fujii Y Fujimori S, Masui T, Matsuoka Y (2017c) AIM/CGE V2.0 model (2020) Investigating the economics of the power sector under formula. In: Fujimori S, Kainuma M, Masui T (eds) Post-2020 high penetration of variable renewable energies. Appl Energy climate action: global and Asian perspective. Springer, pp 267:113956. https ://doi.org/10.1016/j.apene rgy.2019.11395 6 201–303 Matsuo Y, Yanagisawa A, Yamashita Y (2013) A global energy out- Fujimori S, Oshiro K, Shiraki H, Hasegawa T (2019) Energy trans- look to 2035 with strategic considerations for Asia and Mid- formation cost for the Japanese mid-century strategy. Nat Com- dle East energy supply and demand interdependencies. Energy mun 10(1):4737. https ://doi.org/10.1038/s4146 7-019-12730 -4 Strategy Rev 2:79–91. https://d oi.org/10.1016/j.esr.2013.04.002 Gambhir A et al (2019) Energy system changes in 1.5 °C, well below Matsuo Y et  al (2018) A quantitative analysis of Japan’s opti- 2 °C and 2 °C scenarios. Energy Strategy Rev 23:69–80. https mal power generation mix in 2050 and the role of CO -free ://doi.org/10.1016/j.esr.2018.12.006 1 3 410 Sustainability Science (2021) 16:395–410 hydrogen. Energy 165:1200–1219. https ://doi.or g/10.1016/j. uncertain nuclear policy. Clim Policy 19(9):1117–1131. https:/ / energ y.2018.09.187doi.org/10.1080/14693 062.2019.16345 07 Ministry of the Environment (2016) Long-term, low-carbon vision. Sugiyama M (2012) Climate change mitigation and electrification. https ://www.env.go.jp/counc il/06ear th/y0618 -14/mat03 -1.pdf Energy Policy 44:464–468. https ://doi.or g/10.1016/j.en pol Ministry of the Environment. https ://www.env.go.jp/earth /ondan ka/ .2012.01.028 ghg-mrv/emiss ions/resul ts/mater ial/kakuh ou_all_2018.pdf Sugiyama M, Akashi O, Wada K, Kanudia A, Li J, Weyant J (2014) Nishio K, Nakano K (2020) Study on initiatives for building decar- Energy efficiency potentials for global climate change mitigation. bonization-Case studies of US states and local governments and Clim Change 123(3–4):397–411. https ://doi.org/10.1007/s1058 implications for Japan-, CRIEPI Research Report, Y19005. (in 4-013-0874-5 Japanese) Sugiyama M, Fujimori S, Wada K, Endo S, Fujii Y, Komiyama R, Kato Oshiro K, Masui T (2015) Diffusion of low emission vehicles and E, Kurosawa A, Matsuo Y, Oshiro K, Sano F, Shiraki H (2019) their impact on C O emission reduction in Japan. Energy Policy Japan’s long-term climate mitigation policy: multi-model assess- 81:215–225. https ://doi.org/10.1016/j.enpol .2014.09.010 ment and sectoral challenges. Energy 167:1120–1131. https: //doi. Oshiro K et al (2017) Implications of Japan’s 2030 target for long-term org/10.1016/j.energ y.2018.10.091 low emission pathways. Energy Policy 110:581–587. https ://doi. Sugiyama M, Fujimori S, Wada K et al (2021) EMF 35 JMIP study org/10.1016/j.enpol .2017.09.003 for Japan’s long-term climate and energy policy: scenario designs Oshiro K, Gi K, Fujimori S, van Soest HL, Bertram C, Després J, and key findings. Sustain Sci. https://doi.or g/10.1007/s11625-021- Masui T, Rochedo P, Roelfsema M, Vrontisi Z (2019) Mid-cen-00913 -2 tury emission pathways in Japan associated with the global 2 °C Unruh G (2000) Understanding carbon lock-in. Energy Policy 28:817– goal: National and global models’ assessments based on carbon 830. https ://doi.org/10.1016/S0301 -4215(00)00070 -7 budgets. Clim Change. https://doi.or g/10.1007/s10584-019-02490 Wachsmuth J, Duscha V (2019) Achievability of the Paris targets in the -x EU—the role of demand-side-driven mitigation in different types Oshiro K, Fujimori S (2020) Stranded investment associated with rapid of scenarios. Energ Effi 12:403–421. https ://doi.or g/10.1007/ energy system changes under the mid-century strategy in Japan. s1205 3-018-9670-4 Sustain Sci. https ://doi.org/10.1007/s1162 5-020-00862 -2 Wakiyama T, Kuramochi T (2017) Scenario analysis of energy saving Ozawa A et al (2018) Hydrogen in low-carbon energy systems in Japan and CO2 emissions reduction potentials to ratchet up Japanese by 2050: the uncertainties of technology development and imple- mitigation target in 2030 in the residential sector. Energy Policy mentation. Int J Hydrogen Energy 43:18083–18094. https ://doi. 103:1–15. https ://doi.org/10.1016/j.enpol .2016.12.059 org/10.1016/j.ijhyd ene.2018.08.098 Wei M, Nelson J, Greenblatt J, Mileva A, Johnston J, Ting M, Yang Quiggin D, Buswell R (2016) The implications of heat electrifica- C, Jones C, McMahon J, Kammen D (2013) Deep carbon reduc- tion on national electrical supply-demand balance under pub- tions in California require electrification and integration across lished 2050 energy scenarios. Energy 98:253–270. https ://doi. economic sectors. Environ Res Lett 8(1):014038. https ://doi. org/10.1016/j.energ y.2015.11.060org/10.1088/1748-9326/8/1/01403 8 Prime Minister’s Office of Japan (2020) Prime Minister Suga’s Williams J et  al (2012) The technology path to deep greenhouse statement of belief. https ://www .k ante i.go.jp/jp/99_sug a/s t ate gas emissions cuts by 2050: pivotal role of electricity. Science ment/2020/1026s hoshi nhyom ei.html 335:53–59. https ://doi.org/10.1126/scien ce.12083 65 Raghavan S, Wei M, Kammen D (2017) Scenarios to decarbonize resi- Zhang Q, Ishihara K, Mclellan B, Tezuka T (2012) Scenario analysis dential water heating in California. Energy Policy 109:441–451. on future electricity supply and demand in Japan. Energy 38:376– https ://doi.org/10.1016/j.enpol .2017.07.002 385. https ://doi.org/10.1016/j.energ y.2011.11.046 Sato O (2005) A study on long-term energy scenarios for Japan. Zhang R, Fujimori S (2020) The role of transport electrification in JAERI-Res. https ://doi.or g/10.11484 /jaer i -r esea r c h-2005-012 global climate change mitigation scenarios. Environ Res Lett ((in Japanese) [accessed May 29, 2020]) 15:034019. https ://doi.org/10.1088/1748-9326/ab665 8 Seto K et al (2016) Carbon lock-in: types, causes, and policy impli- cations. Annu Rev Environ Resour 41:425–452. https ://doi. Publisher’s Note Springer Nature remains neutral with regard to org/10.1146/annur ev-envir on-11061 5-08593 4 jurisdictional claims in published maps and institutional affiliations. Shiraki H, Sugiyama M, Matsuo Y et al (2021) The role of renewables in the Japanese power sector: implications from the EMF35 JMIP. Sustain Sci. https ://doi.org/10.1007/s1162 5-021-00917 -y Silva HD, Fujimori S, Kainuma M (2019) Implications of Japan’s long term climate mitigation target and the relevance of 1 3

Journal

Sustainability Science – Springer Journals

Published: Mar 2, 2021

There are no references for this article.