著者

尾羽 秀晃 遠藤 聖也 松尾 雄司 玄海 亨 長尾 吉輝

出版者

一般社団法人 エネルギー・資源学会

雑誌

エネルギー・資源学会論文誌 (ISSN:24330531)

巻号頁・発行日

vol.43, no.4, pp.162-171, 2022-07-10 (Released:2022-07-10)

参考文献数

32

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Increasing variable renewable energies with zero marginal cost cause the decline of wholesale electricity prices and undermine their own value by “cannibalization effect”. While capital costs of renewable energies are expected to decline, their income is also to decrease because of declined wholesale electricity prices. This study integrated GIS (geographic information system) model that assesses business feasibility into an optimal power generation mix model that assess wholesale electricity prices. By developing an integrated model, it is possible to assess potential installation capacity of solar and wind energy by considering both economic rationality and land use restrictions. In the case of Japan, this study revealed that increasing solar and wind energies cause the significant decline of wholesale electricity prices in specific electric network area such as Hokkaido. Even if capital costs of these energies decrease through learning effect, economic potential of installed renewable capacities is significantly limited if business feasibility is considered. Thus, the decline of electricity prices by cannibalization effect can seriously stagnate installation of both solar and wind energies. This study implies that further cost reduction faster than previous trend is needed to realize “subsidy-free” energy sources when cannibalization effect is considered.

著者

大槻 貴司 尾羽 秀晃 松尾 雄司 森本 壮一

出版者

一般社団法人 エネルギー・資源学会

雑誌

エネルギー・資源学会論文誌 (ISSN:24330531)

巻号頁・発行日

vol.44, no.3, pp.115-125, 2023-05-10 (Released:2023-05-10)

参考文献数

14

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The authors’ previous assessment indicated that the marginal electricity cost in 2050 in Japan is more than doubled in an energy system based on a 100% renewable power supply compared to the cost-optimal system. However, some assumptions may be conservative given the recent developments, including the cost of variable renewable energy (VRE) and energy storage technologies and the availability of dispatchable renewable power generation (such as biomass-fired). Therefore, to test the robustness of the previous assessment, this study conducts a sensitivity analysis with a focus on these factors, using an energy system optimization model with a detailed temporal resolution. Simulation results imply that the high marginal electricity cost in the “100% renewable power system” is partially due to the costs of managing VRE’s seasonality. Low-cost energy storage and dispatchable renewable power plants can curb the marginal electricity cost. However, the results also suggest that the marginal cost in these sensitivity cases remains high compared to the cost-optimal system, still posing economic challenges to the system based on a 100% renewable power supply.

著者

大槻 貴司 尾羽 秀晃 川上 恭章 下郡 けい 水野 有智 森本 壮一 松尾 雄司

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.142, no.7, pp.334-346, 2022-07-01 (Released:2022-07-01)

参考文献数

53

被引用文献数

2

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This study investigated cost-effective energy mix for realizing net zero CO2 emissions in Japan by 2050, employing an energy system optimization model with hourly electricity balances. The detailed temporal resolution enables the model to capture intermittency of variable renewable energy (VRE) and costs of system integration measures. Siting constraints on VRE, such as prohibiting solar PV and onshore wind developments in forest and offshore wind developments inside fishery rights area, are incorporated in the model to reflect the environmental protection and social acceptance perspectives. Simulation results imply that a well-balanced power generation mix, combining renewables, nuclear, gas-fired with carbon capture and storage, as well as ammonia-fired, would contribute to curbing mitigation costs. In contrast, a simulation case with very high VRE penetration poses economic challenges. Average shadow price of electricity in 2050 in a 100% renewables case (RE100) is projected to be more than doubled from a reference case which is based on middle-of-the-road assumptions. Marginal CO2 abatement cost in 2050 increases from 49,200 JPY/tCO2 in the reference case to 75,300 JPY/tCO2 in the RE100 case. The economic viability of high VRE penetration is improved by relaxing the siting constraints, although it may raise environmental and social concerns.