The Implications of Household PV-Battery Systems for Utilities in Thailand

Abstract

Driven by decreasing PV and battery installation costs and mismatch between household demand and PV generation, household PV-battery systems are going to be deployed in the country and create significant implications for utilities in Thailand. This paper mainly discusses both negative and positive impacts of household PV-battery systems on Thai utilities. The use of household batteries (storing excess generation from PV during daytime and discharging it in the evening) can increase solar capacity values and energy values to power system, mitigate the problem of “duck curve” and decrease PV integration cost. Household customers can consume more PV electricity (increasing PV self-consumption ratio) from the inclusion of batteries. As a result, it leads to higher revenue losses and lower re-sale of exported electricity from PV to distribution utilities, while it is not the case for generation/transmission utilities since re-sale of exported electricity is only relevant to distribution power system and revenue losses of generation/transmission utilities remain unchanged. This is because with household batteries, the level of PV installation is the same (only shifting the consumption of household PV excess generation from daytime to evening). Therefore, it is necessary to precisely quantify each cost and benefit component in order to understand values of household batteries to the power system.