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Share of Renewable Energy Electricity in 2024 (Calendar Year), Preliminary Report

Japan’s renewable share continues to rise, but the slow growth of variable renewables, persistent reliance on thermal power, and uneven grid flexibility leave it well behind leading countries and in urgent need of accelerated deployment and system reform.

2024年(暦年)の自然エネルギー電力の割合(速報)

Institute for Sustainable Energy Policies · By Institute for Sustainable Energy Policies · 30 June 2025 · read the original in Japanese →

Share of renewable energy electricity in 2024 (calendar year), preliminary report. June 30, 2025. Variable renewable energy in Japan reaches 12 percent, making further expansion of renewable energy an urgent task. Institute for Sustainable Energy Policies, nonprofit organization. June 30, 2025. Summary: the share of renewable energy in domestic electricity generation.

Using the Electricity Survey Statistics [1], nationwide electricity supply-and-demand data, and other sources, we estimated the share of Japan’s total domestic electricity generation in 2024, by power source, including self-consumption [2]. The result shows that renewable energy accounted for 26.7 percent of total electricity generated in Japan in calendar year 2024 (Table 1, Figure 1).

The share of renewable energy, which had been about 15 percent in 2016, rose by more than one percentage point every year until 2021, reaching 22 percent; in 2024 it rose by one point from the previous year, 2023, to reach 26.7 percent (Figure 2). Within this, electricity generated from solar power reached 11.4 percent, a slight increase from 11.2 percent the previous year, gradually approaching the deployment share of 15 percent assumed in the Basic Energy Plan’s 2030 power mix. Together with wind power’s 1.13 percent share, VRE, or variable renewable energy, accounted for 12.6 percent, only a slight increase from 12.3 percent in 2023. Among renewable sources other than solar power, biomass generation accounted for 5.9 percent, essentially flat from 5.7 percent the previous year. Wind power also rose slightly, to 1.13 percent from 1.07 percent the previous year, and geothermal power also increased marginally, to 0.33 percent. Hydropower rose from 7.5 percent the previous year to 7.9 percent. By month, the share of renewable electricity generation was highest in May 2024, reaching 34.7 percent (Figure 3). In that May, the solar share was high, at 15.8 percent, and the share of variable renewable energy, or VRE, also reached 17.1 percent.

For data on electricity generated by wind power, we use transmitted electricity volumes from the electricity supply-and-demand data published by electric utilities, rather than data from the Electricity Survey Statistics, namely electricity transmitted by electricity businesses and electricity received. For data on electricity generated by solar power, we adopt the Electricity Survey Statistics; however, since these figures are about 10 percent larger in annual transmitted volume than the electricity supply-and-demand data, it should be noted that the estimated share of solar power has a range. Specifically, the estimate from the Electricity Survey Statistics puts annual solar generation at 114.6 TWh, while the transmitted volume in the electricity supply-and-demand data was 93.4 TWh. Since the estimated figure for residential solar power, under 10 kW, is 3.2 TWh, adding that brings the total to 96.6 TWh, more than 10 percent lower, which would make the share of solar power 9.6 percent. The generation estimate from the Electricity Survey Statistics is the sum of reported generation results from electricity businesses, namely retail electricity providers and generators above a certain scale, and electricity received from entities other than electricity businesses; it is therefore possible that the figure is somewhat inflated by double counting or similar factors.

Electricity generated by thermal power is on a declining trend. In 2024 it stood at 65.1 percent, down from 66.6 percent the previous year and more than about 18 percentage points lower than in 2016, but it remains at a high level. Coal-fired power fell from 30.2 percent in 2016 to 28.2 percent in 2024. LNG has been on a nearly consistent downward trend, from 38.9 percent in 2016 to 29.1 percent in 2024. Nuclear power, meanwhile, after falling to zero in 2014, rose to 6.5 percent of generated electricity in 2019, declined to 4.8 percent in 2022, and then increased to 8.2 percent in 2024.

Table 1: Trends in the share of renewable energy in Japan’s total electricity generation. Source: prepared by ISEP from the Electricity Survey Statistics and other data.表1: 日本の全発電電力量に占める自然エネルギーの割合の推移 (出所：電源調査統計などよりISEP作成)

Figure 1: Japan’s overall power mix, preliminary 2024 figures. Source: prepared by ISEP from the Electricity Survey Statistics and other data. Figure 2: Trends in the share of renewable energy in Japan’s total electricity generation. Source: prepared by ISEP from the Electricity Survey Statistics and other data.

Figure 3: Monthly share of renewable energy in Japan’s total domestic electricity generation, preliminary 2023 figures. Source: prepared by ISEP from the Electricity Survey Statistics and other data. Figure 4: Trends in annual electricity generation and the power mix in Japan. Source: prepared by ISEP from the Electricity Survey Statistics and other data. Comparison of renewable energy deployment shares with other countries.

In the introduction of renewable energy in the electricity sector, initiatives in the EU, or European Union, have led the world since the 1990s. The share of electricity generation for the EU as a whole reached 47.5 percent across the 27 member states in 2024, far exceeding the 29.1 percent share of fossil-fuel generation. This is nearly twice the share of renewable electricity in Japan. The share of variable renewable energy, or VRE, such as solar and wind power, was also 28.6 percent across Europe as a whole, more than double Japan’s roughly 12 percent.

Figure 5 shows the breakdown of the share of annual electricity generation from renewable energy in 2024 for major European countries, the United States, China, and Japan. The figure is based on the latest 2024 data for the power sectors of countries worldwide, estimated by the British think tank Ember [3]. In Denmark, where the share of variable renewable energy, wind and solar VRE, has already reached 69 percent, renewable energy accounts for 88 percent of annual electricity generation, with wind alone accounting for 58 percent. In Austria, hydropower accounts for 57 percent, and together with wind at 12 percent and solar at 11 percent, the renewable energy share reaches 86.7 percent. The share has reached 85.2 percent in Portugal and 69.5 percent in Sweden; already in Germany, at 57.4 percent, Spain, at 57.2 percent, and the United Kingdom, at 51.5 percent, renewables account for more than 50 percent and exceed the European average. The VRE share has reached 28.6 percent in the EU as a whole, and 43 percent in both Spain and Germany. In France, by contrast, where nuclear power exceeds 68 percent, renewable energy remains at 26 percent.

Figure 5: Comparison of the shares of renewable energy and other sources in electricity generation in European countries, the United States, China, and Japan, 2024. Source: prepared by ISEP from Ember data.

Comparing trends from the 1990s to 2023 in the share of renewable energy in annual electricity generation in European countries and Japan shows that European countries steadily increased the renewable share from the 1990s toward 2020 (Figure 6). In Denmark, the share was already 17 percent in 2000, exceeded 30 percent in 2010, and reached 87 percent in 2023; the country aims for renewable electricity to exceed 100 percent by 2030 [4]. In Denmark, through two decades of experience in its electricity system since 2000, integrated solutions have been realized in the power system and electricity market to supply more than 50 percent of electricity from wind and solar variable renewable energy, or VRE.

Figure 6: Actual deployment and policy targets for renewable electricity in European countries and Japan. Source: prepared by ISEP from Eurostat, Ember data, and other sources.

In Germany, the share of renewable electricity was about 7 percent in 2000, but then rose to nearly 20 percent in 2010, reached 45 percent in 2020, and reached 57 percent in 2024 (Figure 7). In response to the Ukraine crisis and in order to break dependence on Russian natural gas, the new 2022 EEG bill, the Renewable Energy Act, set a target of more than 80 percent renewable electricity by 2030 and 100 percent by 2035. Nuclear power, meanwhile, had fallen to zero by the end of 2023, dropping from 29 percent in 2000 to 0 percent in 2024. It had been steadily reduced toward the legally mandated phaseout at the end of 2022, but because of concerns over natural gas supply, measures were taken to keep in service until April 2023 nuclear plants that had been scheduled for closure. Coal, including domestically produced lignite, accounted for 50 percent in 2000, but by 2024 had fallen to 22 percent, below the share of wind power. In addition, Germany’s annual solar power installations reached 15 GW in 2024, about six times Japan’s annual installations of 2.5 GW, and cumulative installed capacity reached around 90 GW, comparable to Japan’s (Figure 8). Germany’s solar deployment target for 2030 is 215 GW, about twice Japan’s, and the annual deployment target will rise from the current 9 GW to 22 GW. For small-scale solar in particular, tax incentives and simplified procedures have advanced, and systems that focus support on rooftop installations on homes and other buildings account for about two-thirds of annual installations.

Figure 7: Trends in electricity generated from renewable energy in Germany and its share of total electricity generation. Source: prepared by ISEP from AGEB [5] and Ember data.

Figure 8: Installed capacity of solar power facilities in countries around the world, end of 2024. Source: IRENA data.図8：世界各国の太陽光発電設備の導入設備容量(2024年末) 出所:IRENAデータ

In the UAE Consensus agreed at COP28 in December 2023 by countries around the world, including Japan, the parties aim to triple global renewable energy generation capacity by 2030 compared with 2022 and to double the global average rate of improvement in energy efficiency. The scale of renewable energy deployment required by 2030 has already been indicated in scenarios and reports by the IEA, or International Energy Agency [6], and IRENA, or International Renewable Energy Agency [7]; renewable energy capacity must be increased from 3.4 TW in 2022 to more than triple that level, 11 TW, by 2030. Achieving this will require 1 TW, or 1,000 GW, of new installations each year [8]. In contrast, in 2024 more than 450 GW of solar power and more than 100 GW of wind power were installed worldwide, meaning that more than 500 GW, or 0.5 TW, of renewable energy capacity was installed in the year (Figure 9).

Figure 9: Trends in global installations of solar power, wind power, and nuclear power. Source: prepared from IRENA, IAEA, and other data.図9：世界の太陽光発電、風力発電および原子力発電の導入量の推移出所：IRENA、IAEAなどのデータより作成

At the same time, countries are advancing the deployment of stationary storage batteries, including batteries on the demand side where solar power has been installed and grid-scale batteries to improve the flexibility of power systems. At COP29, held in Azerbaijan in November 2024, more than 60 countries, including Japan, endorsed a pledge to increase storage capacity sixfold by 2030 [9]. China, which ranks first in the world in the deployment of solar and wind power, has made the greatest progress in deploying storage batteries, followed by the EU and the United States (Figure 10). Within the EU, Germany and Italy, where solar power deployment is large, also have large volumes of storage battery deployment, and the level of deployment in Japan is comparable. In Japan, stationary storage batteries with more than 10 GWh of storage capacity have been installed, equivalent to roughly one-tenth of the storage capacity of domestic pumped-storage hydropower. Globally, storage batteries are now being installed at capacities comparable to pumped-storage hydropower, which has until now provided flexibility in power systems.

Figure 10: Cumulative installed capacity of stationary storage batteries in countries around the world, end of 2024.図10: 世界各国の定置用蓄電池の累積導入量(2024年末)

Source: prepared from European Market Outlook for Battery Storage 2025-2029, materials from the Ministry of Economy, Trade and Industry, and other sources.

In China, the deployment of wind and solar power, in addition to hydropower, has advanced rapidly over the past decade. In 2024, wind power accounted for 9.8 percent of annual generation and solar power for 8.3 percent, bringing the share of VRE, or variable renewable energy, to 18.1 percent (Figure 11). Including hydropower, renewable energy accounted for 33.6 percent of electricity generated. The nuclear share, meanwhile, was 4.4 percent and had been almost flat since 2019, so solar power greatly surpassed nuclear power in electricity generation. The scale of China’s annual domestic electricity generation in 2024, 10,073 TWh, was 3.7 times the EU’s 27-country total of about 2,744 TWh and more than 10 times Japan’s 1,022 TWh. Electricity generation in Europe and Japan is flat or trending downward, but in China it has continued to increase with economic growth, more than doubling over the past decade.

Figure 11: Trends in electricity from renewable energy and nuclear power in China. Source: prepared from China Energy Portal and Ember data. The share of renewable energy in Japan’s domestic electricity supply and demand.

Based on electricity supply-and-demand data published monthly by the ten general transmission and distribution utilities for each area across Japan, we aggregated data for the full calendar year 2024, focusing on the share of renewable energy in grid electricity demand. For electricity supply-and-demand data in Japan, ISEP’s Energy Chart makes it possible to analyze published data interactively and clearly through a variety of graphs [10].

The share of renewable energy in Japan’s total annual electricity demand averaged 23.2 percent in calendar year 2024, up from the 2023 annual average of 22.5 percent (Figure 12). In the breakdown, solar power accounted for 10.6 percent; together with wind power at 1.3 percent, the share of variable renewable energy, or VRE, was 11.9 percent. Solar fell from 10.8 percent in 2023, but its share was larger than that of hydropower, at 8.2 percent. Biomass power increased from 2.3 percent the previous year to 2.8 percent. Nuclear power’s share in 2024 was 9.8 percent, up from 9.0 percent the previous year.

Figure 12: Monthly shares of renewable energy and nuclear power in nationwide electricity supply and demand in Japan, 2024. Source: prepared from electricity supply-and-demand data of general transmission and distribution utilities.

In monthly averages of the share of renewable energy in electricity demand for Japan as a whole, May 2024 was the highest, at 32.2 percent, down from 32.5 percent the previous year. At that time the share of VRE, or variable renewable energy, was also at its maximum, 16.9 percent, higher than the 16.5 percent recorded in May of the previous year. The breakdown was 15.4 percent solar power and 1.5 percent wind power. In daily averages, the share reached 43.7 percent on May 3, 2024, and VRE also reached its maximum that same day, at 25.7 percent. In hourly values for the renewable energy share, the annual peak was 80.1 percent during the 11 a.m. hour on the same May 3; solar reached 63.7 percent, and together with wind power at 2.0 percent, the VRE peak value was 65.7 percent. The peak value for wind power, incidentally, was 5.3 percent in the early hours of October 20, 2024.

By electric utility, or general transmission and distribution utility, area, the highest average share of renewable energy in annual electricity demand in calendar year 2024 was in the Tohoku area, at 41.5 percent (Figure 13). Solar accounted for 13.5 percent and wind for 5.8 percent, bringing the VRE share to 19.3 percent; biomass power, at 6.7 percent, and geothermal power, at 1.5 percent, were the highest in the country, while hydropower also accounted for a large share, at 14.0 percent. The Hokkaido area ranked second with a renewable energy share of 40.1 percent, but its wind power share, at 9.7 percent, was the highest in the country, and its VRE share, at 20.3 percent, was also the highest in Japan. The average for eastern Japan as a whole in 2024 was a renewable energy share of 22.2 percent, below the national average of 22.8 percent. A major factor is that the Tokyo area remained at 14.9 percent. The VRE share, however, was 12.0 percent, above the national average of 11.8 percent. The reason is that the wind power share was 2.1 percent, above the national average of 1.3 percent.

Figure 13: Share of renewable energy in electricity supply and demand by area, 2024. Source: prepared from electricity supply-and-demand data of general transmission and distribution utilities.図13: エリア別の電力需給における自然エネルギーの割合(2024年) 出所：一般送配電事業社の電力需給データより作成

In 2024, the renewable energy share for central and western Japan as a whole was 24.0 percent, above the national average of 23.2 percent, while the VRE share, combining solar at 11.1 percent and wind at 0.6 percent, was 11.7 percent. Nuclear power, by contrast, was almost zero in eastern Japan, at 0.1 percent, but was operating in central and western Japan in the Kansai, Kyushu, and Shikoku areas; its share was 17.7 percent, far exceeding VRE and rising substantially from 10.7 percent the previous year. In the Hokuriku Electric Power area, which ranked third in renewable energy share, the figure reached 37.1 percent in 2024. Solar was 5.8 percent and wind 0.5 percent, making the VRE share a relatively low 6.3 percent, while hydropower accounted for 28.5 percent, the highest share in Japan. In the Shikoku area, which ranked fourth in renewable energy share, the figure was 35.0 percent, up from 34.4 percent in 2023, while the nuclear share was essentially flat at 21.9 percent, compared with 21.7 percent the previous year. In the Shikoku area, solar accounted for 16.2 percent, as in the Kyushu area, the highest share in the country; combined with wind at 2.0 percent, the VRE share was 18.2 percent, among the higher levels nationwide after Hokkaido, at 20.3 percent, and Tohoku, at 19.3 percent. In the Kyushu area, the renewable energy share was 29.9 percent and the VRE share 17.1 percent. Of this, solar accounted for 16.2 percent, up from 15.8 percent the previous year, while wind accounted for 0.9 percent. At the same time, the nuclear share reached 34.5 percent, the highest in the country together with Kansai Electric Power.

In 2024, there were five areas where renewable energy exceeded 100 percent of electricity demand in hourly values: Hokkaido, Tohoku, Hokuriku, Shikoku, and Chugoku (Figure 10). Among these, in the Tohoku area, the share of renewable energy relative to electricity demand reached 131.5 percent during the 11 a.m. hour on April 21, 2024. At that peak, solar was 92.4 percent and wind 5.5 percent, making the VRE share 97.9 percent. Adding hydropower at 24.9 percent and biomass at 6.6 percent brings the total to 131.5 percent. In the Chugoku area, the renewable energy share reached a maximum of 115.4 percent, and the VRE share also reached 104.7 percent, with solar at 103.1 percent and wind at 4.1 percent. In the Kyushu area, where the curtailment rate is highest, the solar share in hourly values reached a maximum of 94.8 percent at its peak. The VRE ratio also remained at a maximum of 83.7 percent. Before curtailment, however, the VRE ratio in the Kyushu area reached a maximum of 113.9 percent, and VRE curtailment suppressed the VRE ratio to 54 percent, a curtailment rate of 46 percent.

In the Kyushu area, curtailment of VRE, solar and wind power, has been implemented among Japan’s areas since 2018, but the VRE curtailment rate over the full year 2024 was 4.4 percent, a sharp decline from 8.9 percent in fiscal 2023. The Kyushu area has about 4 million kW of nuclear power capacity, and in 2024 the nuclear share of electricity was 34.5 percent, about the same as the previous year. By around April 2023, VRE curtailment had also begun in other areas except the Tokyo area. In areas where nuclear power is operating, the share of VRE output curtailment was 2.9 percent in Shikoku and 2.1 percent in Kansai. In areas without operating nuclear power, curtailment was kept low: 0.04 percent in Hokkaido, 1.2 percent in Hokuriku, 0.33 percent in Chubu, and 0.18 percent in Okinawa; by contrast, the Chugoku area had a relatively high VRE curtailment share of 2.36 percent. The national average curtailment rate was 1.5 percent, down from 1.7 percent the previous year. The rules for VRE curtailment have been revised, and the use of online control for VRE is advancing, but the rules have become more complex and the electricity system as a whole has not yet been optimized. In the Kyushu area, interregional interconnection lines are gradually being used effectively, but supply-and-demand adjustment over a wider region that includes the Shikoku, Chugoku, and Kansai areas is still insufficient; further improvements in the operation of interconnection lines, including those in other areas, and reinforcement of interconnections are therefore required. There are areas such as Kyushu where pumped-storage hydropower is being used sufficiently and other areas where it is not yet being fully used. The first requirements are to promote and optimize online control of VRE and to review the minimum output of thermal power plants; going forward, the use of storage batteries, DR, or demand response, VPPs, or virtual power plants, and other resources will be required.

References:参考：

[1] Electricity Survey Statistics, http://www.enecho.meti.go.jp/statistics/electric_power/ep002/

[2] In the estimate, figures from the previous year are used for estimates of captive generation and self-consumption of residential solar power from October 2021 onward, but the effect is considered small.

[3] Ember (2025), “Global Electricity Review 2025,” https://ember-energy.org/latest-insights/global-electricity-review-2025/

[4] Danish Energy Agency, “Development of Flexibility and Its Role in Denmark’s Power System,” https://www.isep.or.jp/archives/library/13612

[5] AGEB, “STROMMIX 1990-2023,” https://ag-energiebilanzen.de/ [6] IEA (2023), “Net Zero Roadmap.”

[7] IRENA (2023), “World Energy Transitions Outlook 2023: 1.5°C Pathway.”

[8] IRENA (2024), “Delivering on the UAE Consensus: Tracking Progress toward Tripling Renewable Energy Capacity and Doubling Energy Efficiency by 2030.”

[9] COP29 Global Energy Storage and Grids Pledge, https://cop29.az/en/pages/cop29-global-energy-storage-and-grids-pledge

Share of Renewable Energy Electricity in 2024 (Calendar Year), Preliminary Report

Figure 8: Installed capacity of solar power facilities in countries around the world, end of 2024. Source: IRENA data.図8：世界各国の太陽光発電設備の導入設備容量(2024年末) 出所:IRENAデータ

Figure 9: Trends in global installations of solar power, wind power, and nuclear power. Source: prepared from IRENA, IAEA, and other data.図9： 世界の太陽光発電、風力発電および原子力発電の導入量の推移 出所：IRENA、IAEAなどのデータより作成

Figure 10: Cumulative installed capacity of stationary storage batteries in countries around the world, end of 2024.図10: 世界各国の定置用蓄電池の累積導入量(2024年末)

References:参考：

[10] ISEP Energy Chart, http://www.isep.or.jp/chart/[10] ISEP Energy Chart http://www.isep.or.jp/chart/

Figure 9: Trends in global installations of solar power, wind power, and nuclear power. Source: prepared from IRENA, IAEA, and other data.図9：世界の太陽光発電、風力発電および原子力発電の導入量の推移出所：IRENA、IAEAなどのデータより作成