Development of Energy Demand-supply Model with Photovoltaics after the End of Purchase Period of Feed-in Tariff and Solid Oxide Fuel Cells

Abstract

Expanding renewable energy is essential to realize decarbonization. Increase of capability to balance electricity demand and supply makes further diffusion of renewable energy possible. Part of photovoltaics comes to the end of purchase period of feed-in tariff from 2019 in Japan. It is an opportunity for retail electricity providers to widen supply source, but it carries a risk of imbalance settlement. The risk is expected to increase when imbalance system is revised in future. Therefore, it is significant to ensure measures to offset the imbalance caused by prediction error of photovoltaic generation. Some previous studies have analyzed imbalance reduction using CHP with renewable energies, but there are few studies focused on aggregation of home PV and fuel cell for imbalance control. Here we developed energy demand-supply model considering supply from aggregated home solid oxide fuel cell (SOFC) to evaluate its contribution to imbalance compensation. We found that imbalance can be reduced and balance of payments can be improved through output control of SOFC. The effect increases if incentive index of imbalance fee is risen. In addition, we found that SOFC can contribute to greenhouse gas emission reduction by both substitution of grid electricity and support of stable supply from PV. This result indicates value of SOFC from in terms of stabilization of energy system, economic efficiency of retail electricity providers and climate change mitigation.