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

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
松尾 雄司 遠藤 聖也 永富 悠 柴田 善朗 小宮山 涼一 藤井 康正
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.40, no.3, pp.49-58, 2019 (Released:2019-05-10)
参考文献数
29
被引用文献数
2

In this paper, we used an optimal power generation mix (OPGM) model, as well as meteorological data from 2000 to 2017, to assess the cost of achieving 100% renewable electricity mix in 2050 in Japan. Although the potentials of variable renewable energies, such as wind and solar PV, have been estimated to be large in Japan, grid-related system costs become significant in the cases with very high shares of variable renewables. Particularly, two factors affect the overall costs: The cumulative installed capacity of offshore-wind power, and the required capacity of electricity storage systems. The former is dependent on the curtailment ratio of onshore-wind and solar PV, whereas the latter is determined by the short-time “windless and sunless” factor, i.e. the maximum number of successive days with very small wind and solar power output. The analyses presented in this study highlight the necessity of using long-term meteorological data when estimating the economics of high penetration of variable renewables, as well as the importance of considering the risk of power supply disruption.
著者
星野 優子 杉山 大志
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.32, no.1, pp.22-27, 2011 (Released:2019-08-08)
参考文献数
15

We compared the generation costs of photovoltaic (PV) with thermal and nuclear power during the period of the recent price surge of fossil fuels and raw materials by a bottom up analysis using a Japanese life cycle assessment (LCA) data for power plants. Although the steep rise of fossil fuel price had spurred the political mood in favor for renewable energy, we found that the impacts on the cost of PV systems by the price rise were not necessarily small compared to those on the costs of thermal or nuclear power. Due to the price hike of materials from 2003 to 2008, the cost of a PV system had increased by 2.7 yen per kWh. It is close to the price increase of coal power by 3.5 yen per kWh in the same period due to fuel and material price hike. Moreover, the impacts on the cost of a nuclear power were as small as 0.4 yen per kWh in the same period, in spite of the steep rise of uranium price. We conclude that a surge of resource and energy price does not necessarily make PV more cost competitive against nuclear and fossil fuel power, since PV is more material intensive than nuclear and fossil fuel power and the material price also surges when the fuel price does.
著者
上田 嘉紀 太田 豊
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.3, pp.84-93, 2022 (Released:2022-05-10)
参考文献数
38

As the electrification of the transportation sector is being promoted to achieve carbon neutrality, the promotion of battery electric vehicles (BEVs) has become an urgent issue. One of the concerns about BEVs from the user's point of view is the range anxiety that the vehicle may not be able to reach its destination due to power shortage. However, few studies have clarified the timing of the anxiety felt by users. In this study, a questionnaire survey was conducted on domestic users who switched from an engine vehicle to a BEV. As a result, it was found that the timing at which BEV users felt range anxiety and wanted to recharge their vehicles tended to be influenced by recharging habits based on individual personality factors, rather than environmental factors such as BEV driving experience and the density of rechargers. In addition, the SoC ratio of the timing of wanting to recharge was found to be correlated with the timing of recharging the BEV and the timing of recharging the cell phone.
著者
本間 優 土肥 哲哉 吉田 好邦
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.37, no.6, pp.23-31, 2016 (Released:2019-02-08)
参考文献数
42

The objective of this study is to evaluate an agrivoltaic system by reflecting the deterioration of rice yield and quality. The agrivoltaic system means introducing photovoltaic power to agricultural fields. By the notification from Ministry of Agriculture, introducing renewable energy to agricultural fields became limitedly possible. However, current agrivoltaic pioneers do not always consider crop quality deterioration brought from a total life cycle shading. We evaluate a deterioration of growing in a paddy field in Chiba prefecture in Japan. Heading time delayed significantly under the shading condition. Number of ears and weight per an ear were also significantly less under PV panels. Utilizing measured data, we modified the conventional crop model, which simulates rice yield, quality and economic efficiency under the shading weather condition. A 20 percent shading reduces the yield by approximately 20 percent. Number of ears per root accounts for 84 percent of the yield, which indicates early period of the growth needs enough amount of solar radiation for improving the rice growth.
著者
西尾 健一郎
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.42, no.3, pp.175-184, 2021 (Released:2021-05-10)
参考文献数
16

This study analyzed the factors causing the difference in the amount of utility bill payments by housing construction period, using micro data of about 9,000 households. The analysis consisted of (1) building a model of gradient boosting decision tree, which is one of the machine learning techniques, (2) identifying contribution of each household and each feature using SHAP value, which is a novel method to improve the interpretability of machine learning, and (3) revealing the breakdown of differences on a macro level by aggregating each contribution. The results showed that the factors that have reduced the amount of payments in recently constructed houses were partly caused by the spread of heat pump water heaters and IH cooking heaters, in addition to the improvement of housing insulation performance. It was also confirmed that the effects of higher efficiency refrigerators and lighting have been steadily increasing.
著者
張 鈺鑫 李 志東
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.40, no.3, pp.28-38, 2019 (Released:2019-05-10)
参考文献数
37

Japan and China are different in many aspects,such as population,resources,administration,growth stage, electricity mix,and carbon emissions.However,both countries are taking effort to transition to low-carbon society. One of those measures is to promote the development of solar power.In this research, we analyzed the current state and mechanism of PV development in both Japan and China by using econometric model. System price, feed-in tariff (FIT), subsidy, transmission grid improvement, etc. were confirmed to be an influence factor of introduction of PV system for both Japan and China. Also, in order to promote the international competitiveness of domestic solar cells, it is indispensable to expand cumulative output. Simulation analysis was also conducted on future targets formulated by the two countries. As a result, in reference case the tendencies continue as they are, it is predicted that Japan will reach a 130% completion of their objective by 2030, while China will have achieved a 142% by 2020. An effective way to further increase this spread could be found in the reduction of feed-in tariff policies ranges and interest rates, as well as in the increase of carbon taxes in Japan or their introduction in China, respectively.
著者
Myovela Rajabu 今中 政輝 栗本 宗明 杉本 重幸 加藤 丈佳 藤田 美和子
出版者
Japan Society of Energy and Resources
雑誌
エネルギー・資源学会論文誌 (ISSN:24330531)
巻号頁・発行日
vol.42, no.4, pp.257-266, 2021 (Released:2021-07-10)
参考文献数
19

Fast Automated Demand Response (FastADR) is one of the expected measures to control electricity demand of consumers so that the balancing of electricity supply and demand in a short time horizon is improved. Due to their high power consumption in business buildings, Heating Ventilation and Air-conditioning (HVAC) loads are the promising resource for FastADR. However, because of their operational characteristics, HVAC loads do not perfectly follow external control signals. To mitigate this problem, Battery Energy Storage System (BESS) can be used complementarily. This paper proposes a method that coordinates the operation of building’s multi-units air conditioning system and BESS to reduce the required capacity of BESS for supporting HVAC operation in the FastADR. In the proposed method, the BESS discharges to supply the difference between the FastADR signal and HVAC load consumption and then recovers its energy by further adjusting the reference power consumption of the HVAC load, in which the thermal capacity of buildings is considered to reduce the required capacity of the BESS. Numerical simulations are performed to demonstrate the benefit of the proposed coordinated control.
著者
魏 啓為 佐野 史典 秋元 圭吾 日渡 良爾 飛田 健次
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.40, no.5, pp.170-179, 2019 (Released:2019-09-10)
参考文献数
20

This paper analyzed Japan’s fusion energy development scenarios by using a global energy systems model considering a combination of uncertainties of future socioeconomic development, CO2 emission pathways corresponding to the long-term target of the Paris Agreement and future fusion power plants. Fusion power plants will be installed in Japan and could contribute about 20% on average in power sector in the latter half of the century because of the limited-potentials of affordable renewable energies and carbon capture and storage in Japan. The benefit of fusion introduction in Japan is estimated to be about 10 billion US$/yr on average in 2050-2100. Its value increases with reduction of the capital costs of future fusion power plants, lower penetration of fission power plants and deeper decarbonization pathways. When considering unique characteristics of fusion energy development, i.e., long-term and large-scale projects and DEMO as a single step between ITER and a first commercial plant, demonstration and prospect of economic viability under DEMO projects becomes critically important. This systems analysis also suggests that an alternative option of fusion energy which directly produces hydrogen by high-temperature steam electrolysis could become economically attractive.
著者
矢部 邦明 林 泰弘
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.40, no.3, pp.69-77, 2019 (Released:2019-05-10)
参考文献数
17

This paper presents the change of CO2 emission when battery energy storage systems (BESS) are used for increasing self-use of PV energy from rooftop panels, and for decreasing PV output curtailment. A traditional evaluation uses an annual CO2 emission intensity and the charge-discharge loss is evaluated, and then the emission is increased. However, when PV system is largely penetrated and the PV energy curtailment is required by power system constraints, BESS can decrease the curtailment as well as the evening demand when the rate of thermal power is large, and increase the daytime demand when the rate of PV energy is high. So, BESS can decrease CO2 emission considering hourly CO2 emission intensity. Authors quantify these effects by use of an optimization model to minimize annual power generation costs, and a model to minimize annual costs of houses with PV and BESS, and then shows energy chain diagram including energy flow between generation plants and customers. The CO2 emissions from business use customers with PV and BESS, and power charging demand for EV are also evaluated using hourly CO2 emission intensity. Authors show BESS can decrease CO2 emission.
著者
畦地 啓太 堀 周太郎 錦澤 滋雄 村山 武彦
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.35, no.2, pp.11-22, 2014 (Released:2019-02-15)
参考文献数
34
被引用文献数
2

This paper aimed to clarify factors influencing environmental conflict occurrence during the planning stage for wind farm projects in Japan. After studying conflict occurrence situations and the main conflict issues for 155 large-scale projects across Japan, we focused on both physical and social factors as explanatory variables and applied a quantitative method using binary logistic regression analysis. The main findings were: (1) environmental conflicts had occurred in 59 projects as of May 2012 and the main issues could be classified as noise/infrasound, sediment- related disaster/hydrology, landscape, nature destruction and birds (esp. raptors); (2) turbine number and size were influential factors as structural aspects, while there was no significant association between proximity to turbines and conflict occurrence; (3) sites located within natural parks, national protection forests, sediment-related disaster hazardous areas and wildlife protection areas designated by relevant acts and ordinances showed higher conflict occurrence, and proximity to such areas could be influential as well; (4) habitats for Golden Eagle, Mountain Hawk Eagle, White-tailed Eagle and Steller's Sea Eagle significantly encouraged conflict; (5) in terms of social aspects at both the national and prefectural level, conflict occurrence was strongly associated with the existence of past conflict experiences and complaints about noise and/or infrasound generated by operating wind farms.
著者
小澤 暁人 本田 智則
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.41, no.6, pp.254-265, 2020 (Released:2020-11-10)
参考文献数
32

Battery is a key technology in the transition to a low-carbon and resilient energy system. Recently in Japan, residential PV battery system is considered as one of the most promising applications; however, its impacts had not been fully assessed. This study evaluates the effects of residential PV battery system for end-users under various conditions on geological, technological and socio-economic factors. Regional diversity is considered by using data on residential power consumption and PV power generation that were collected from over 40 thousand all-electric houses in Japan. Scenario analysis and sensitivity analysis are performed to evaluate the effects of uncertain parameters on the system’s performances. Simulation results suggest that economic benefits of the system can be improved by changing battery operation mode at the end of purchase period for PV under Feed-in Tariff (FiT) scheme and the benefits should vary depending on the region. The results also indicate that PV self-consumption rate is over 50% when charging the battery with surplus power. Sensitivity analysis results suggest that the unit prices of grid electricity and the purchasing price of surplus power after FiT scheme should have large influences on the economic benefits of the system.
著者
森本 慎一郎 小池 政就 茂木 源人
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.29, no.4, pp.29-35, 2008 (Released:2019-09-26)
参考文献数
23

Various evaluations have performed on oil peak forecasting, by confirming oil reserves data, forecast methods, opinions on reserve growth including non-conventional oil, and new oil field discoveries. However, a holistic overview of the oil peak forecast using statistical analysis, including the regression analysis method, would perhaps provide a new perspective from which to evaluate and confirm trends in the oil peak forecast. Therefore, this paper aims to clarify the principle factor contributing to oil peak forecasts by evaluating oil peak forecast studies from this new perspective. Oil peak year forecasts which predict that innovations in substitute fuels and the oil market force will be the primary contributing factors appear to have risen linearly, while those which indicate that the decline of world conventional oil production is the principle factor appear to be converging on the year 2010. The result of this paper evidently confirms that differing opinions regarding the basic cause of the oil peak have an impact on the oil peak forecasts as they appear in the trends for oil peak forecast studies.
著者
渡部 朝史 村田 謙二 神谷 祥二
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.30, no.3, pp.10-18, 2009 (Released:2019-09-14)
参考文献数
23

Expanding energy resources for electric power plants from fossil energies to cost competitive renewable ones are required for reducing GHG emissions and for coping with the soaring in imported fossil energies prices. Importing natural energy resources as storable and transportable hydrogen transformed from wind power electricity may be preferable, if a large quantity of windmills are constructed in the favored oversea regions, such as Patagonia, where steady and strong wind is blowing over wide area and its electricity cost becomes low. Three kinds of electricity generating systems, based on domestic land windmills, domestic offshore windmills and that composed of electric power plant utilizing imported hydrogen, as mentioned above, are designed and the electricity costs of net power flows from such three systems are derived by estimating construction and running costs for the elements of such systems from open references. The result shows that the electricity cost derived from oversea wind power is comparable with that from domestic land wind power, if the future improvements of energy conversion efficiencies of electrolysis and hydrogen liquefaction are considered, though the construction cost for the oversea wind power system is more than twice of that of the domestic land wind power system.
著者
グリナ カミル 李 志東
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.31, no.5, pp.6-12, 2010 (Released:2019-08-26)
参考文献数
15

This paper conducted quantitative study on the outlook of economy, energy and environment to 2030 of China Xinjiang Uygur Autonomous Region by using econometric method. GDP growth will be over 7% annually between 2006 and 2030, and total primary energy consumption will double by 2030. The continuation of rapid economic growth could result in a lot of difficulties for energy development, environment protection, and CO2 emissions reductions. For the sustainable development, more comprehensive strategies should be adopted, including development of renewable energy with highest priority, improvement in energy efficiency and automobile fuel efficiency, etc. However, substantial governmental involvements and support, as well as the establishment of a regulatory framework are necessary.
著者
岡本 優
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.41, no.5, pp.226-232, 2020 (Released:2020-09-10)
参考文献数
15

Seaweed contains high high-density glucose, from which ethanol or materials such as biodegradable plastic, have been recently produced. A floatable block made from waste glass, that saves on labor and costs, has been developed to culture seaweed. Seaweeds collect nutrients such as nitrogen and phosphorus from eutrophic areas during cultivation. This floatable block would be able to supply nutrients, via a slow release method, in oligotrophic areas; this would constitute most of the exclusive economic zone (EEZ) in Japan. A shortfall in phosphorus supply is feared in the near feature, thereby making it necessary to obtain it from deep sea water through the cultivation of seaweed. The material for the floatable b lock would be supplied from coal ash or incineration ash, and so on by separating rare earth metals and metals using a high high-temperature melting furnace. The separated rare earth metals and metals may be recycled. Large volumes of ethanol made from seaweed can be used as a motor fuel. As the exhaust gases from an ethanol ethanol-fueled car are more toxic than those from a conventionally fueled one, under low low-temperature operation, catalyst activity would need to be assisted by electric discharge with a switching dev ice, namely MOS MOS-assisted gate triggered thyristor (MAGT), which achieves both high speed and high capacity. MAGT was developed for excimer laser.
著者
板岡 健之 木村 誠一郎 広瀬 雄彦 吉田 謙太郎
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.40, no.6, pp.242-249, 2019 (Released:2019-11-11)
参考文献数
10

In response to the introduction of fuel cell vehicles (FCVs) to the commercial market hydrogen station deployment needs to be progressed. Since resources allocated for deployment are limited for either private companies who wish to install stations and governments who provide subsidies, efficient station allocation should be cognizant of the service of potential customers. Based on a literature review, the results of a social survey and data analysis, p-median is chosen to find optimum locations for hydrogen stations. Location and the amount on potential demand for FCV’s in the early stage of deployment is estimated by a regression model. The result of GIS analysis for short mid-term perspective using p-median implies the importance of covering regional hub cities (such as prefectural capital cities) as well as metropolises and the result of GIS analysis for long-term perspective implies the ultimate necessary deployment of hydrogen stations. The locations suggested by the analysis were examined through coverage analysis on existing gasoline stations. The geographical tendency of station locations allocated by the developed methodology provides guidance for hydrogen station location practice.
著者
有馬 理仁 林 磊 福井 正博 島田 幸司
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.39, no.3, pp.11-20, 2018 (Released:2019-02-08)
参考文献数
19

The penetration of renewable energy is advanced to implement low-carbon society. Especially the increase of the photovoltaic generation energy is remarkable. But as a result, the trend that net electricity demand is decreased in the daytime and is increased suddenly in the evening, which is called ‘Duck-Curve phenomenon’ become apparent, and the destabilization of the utility grid caused by the fluctuation of photovoltaic generation power output. To solve this problem, the virtual power plant is planned as one of the solutions, and the battery aggregation using the distributed and cooperated rechargeable batteries is considered as one of the technical elements. One of the strong candidate of rechargeable battery is lithium ion batteries. To maximize the profit of the battery aggregation, it is necessary to diagnose the degradation in real time and estimate the cost effectiveness of lithium ion batteries. We found the convenient technique of diagnosis which can be done under operation of lithium ion batteries and battery management systems. To contribute to optimum system operation of the distributed and cooperated rechargeable batteries, we propose a new cost effectiveness index of lithium ion batteries based on this technique.