In the 2030 new energy mix suggested by 6th Strategic Energy Plan, the ambitious upper limit of photovoltaics (PV) installation rate was set to 117.6GW, which is about two times of the present installation level. PV installation in household is a key factor forward realization of the 2030 new energy mix. However, PV is a variable renewable energy (VRE) which increases power system stabilization cost. Hence, its evaluation and reduction counterplan on the demand side are considered important for the realization of both massive PV installation and power system stabilization.
In this paper, we will analyze power system’s supply and demand for both the case of controlling household distributed energy resources (DER) as usual and the case of optimal control of DER based on variable electricity prices in 2030 Kyusyu area. Thus, we will suggest effect of optimal demand control for both demand side benefit which is electricity bill reduction and supply side benefit which is power system stabilization cost.

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Agrivoltaics, which can generate carbon-free electricity without reducing food self-sufficiency and has the potential to revitalize local communities, is expected to spread in Japan. However, in recent years, solar cell modules, installation methods, and the type of electricity selling methods have diversified, making it difficult to ascertain which combination is most profitable. This study examined the most profitable business model that maximizes profit using GAMS, a numerical optimization simulation model. The results showed that, compared to the conventional method of installing monocrystalline PV at the optimal angle, the combination of different solar cell modules increased the profit approximately 9.2 million yen during 20 years project of electricity sales. This result suggested that, rather than introducing expensive storage batteries, it is important for a profitable business to select the combination of solar cell that fits the demand electricity curve and sell as much electricity as possible to consumers.

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Various organizations are making efforts to reduce CO₂ emissions toward a decarbonized society. Among them, for railway operators, effective utilization of regenerative power is one of the measures to reduce CO₂ in the traction power supply system. However, because the equipment for effective utilization of regenerative power is expensive, there is a problem that it can be installed only in places where the effect is high. Therefore, in this research, we focused on highly versatile EV storage batteries and decided to utilize EVs in the traction power supply system. We proposed a framework that benefits not only railway operators but also EV owners by offering a certain amount of free charging to EV owners at stations, which benefits all stakeholders. In addition to setting detailed charging and discharging conditions for EVs, we conducted studies based on annual simulations using actual data. As a result, we were able to gain a detailed understanding of the EV charge/discharge schedule, as well as the extent to which the amount of free charging required to ensure business continuity.

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In order to analyze and promote the electrification and energy saving of future energy service demand in Japan, we build a housing stock future estimation model using a housing residual rate curve by housing type. We focused on residential water heaters among the household demand appliances and calculated the recent share of water heater technologies by region, by apartment building/household, and by housing vintage, based on statistical data. Next, we set four future scenarios, referring to the government's 6th basic energy plan in Japan in 2030 and industry reports on the number of heat-pump water heaters in stock in 2050. Then, we estimated the future stock of residential water heaters based on assumptions about future trends in water heater market share for each of the four housing segments (apartment/house, existing/newly built). Through this process, we revealed how much the share of HP water heaters in each of the four segments would need to grow to meet the future stock targets set by the government and the industry.

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This paper conducted a conjoint analysis to reveal firms’ intention on utilization of personal data including energy data. The conjoint analysis dealt with four scenarios of data utilization of firms: (1) human resources, (2) marketing, (3) monitoring, and (4) electricity consumption. A questionnaire survey was conducted to collect 1,513 samples of firms, which was used to estimate a discrete choice model. The analysis revealed that the intention to utilize data increases not only when data itself is provided, but also when additional information is provided, and when ancillary services such as a function to outsource the data analysis is available. In addition, it was found that the intention differs statistically significantly depending on the industrial sectors. Also, the intention to use data was higher for firms that had experience in using data.

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As a measure to make renewable energy the main source of electricity for carbon neutrality and to reduce the risk of a balance of expenditure when fuel costs rise, it is necessary to have a mechanism to adjust demand in the residential sector, which accounts for about one-third of all electricity demand. TEPCO and ITOCHU conducted a large-scale verification experiment to confirm the ability of DR commands to control equipment and adjust demand by requesting approximately 300 households to conserve electricity and by controlling equipment through external control of storage batteries. The DR effect was 0.02 kWh per 30-minute period per house in both summer and winter for the behavior-changing DR, and 0.10 kWh in summer and 0.22 kWh in winter for the equipment control type DR. This indicates that DR using storage batteries has a greater effect on demand reduction than DR using the behavior change type, and that it can be done reliably. In the future, we will study and demonstrate the operation method of storage battery control to improve the balance of payments through DR.

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Agrivoltaic power generation has been attracting attention in recent years as an approach that allows farmers to generate solar power while continuing to operate their farms. However, it is difficult to say that this approach is steadily expanding. This study examined the factors necessary for the future expansion of agrivoltaic power generation from the perspective of consumer evaluation of this new initiative. By conducting a questionnaire survey of consumers in the Kanto region, where many agrivoltaic power generation projects are being implemented in Japan. The results of this research study indicate that consumer awareness of agrivoltaic power generation is still low, even in the Kanto region. The study also revealed that a positive image of agriculture may be increasing consumers' evaluation of the power generation aspect of agrivoltaics. It was also suggested that in order to gain consumer acceptance of agrivoltaics, it is necessary to publicize the benefits of global warming mitigation by agrivoltaics and dispel concerns about how agrivoltaics affect the quality of agricultural products and the landscape.

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In Japan, households are responsible for 21% of total greenhouse gas emissions. Notably, it is possible to substantially reduce carbon dioxide (CO₂) emissions by guaranteeing household energy self-sufficiency. Therefore, the authors integrally developed housing components such as photovoltaic power generation systems, storage batteries, air conditioning and ventilation systems for all rooms, and achieved to create houses equipped with a self-sufficient energy unit that contributes to reduce CO₂ emissions. In this study, we demonstrated in actual houses equipped with a self-sufficient energy unit to verify the reduction of CO₂ emissions and the contribution of convenience and comfortableness for the residents. As a result, it was verified that the CO₂ emission was reduced by 7.00 tCO₂/year compared to general housing as of FY2013. Furthermore, we have verified that we can simultaneously provide user benefits such as good temperature and air quality (the air conditioning and ventilation system for all rooms), convenience of being able to easily operate all the air conditioners in the house and home appliances (using smart app), and security that enable to evacuate at home during disasters (by using strong power supply which is useful in a power outage).

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