Optimal Subsidy Systems for Residential Photovoltaic Installation Offered by Local Government Case Study of Saitama Municipalities

Abstract

Installation subsidies for residential photovoltaics provided by local governments are offered all over Japan, yet optimal systems for such measures have not been given full consideration. This study is an analysis of the residential photovoltaic installation subsidy offered by the municipalities of Saitama Prefecture. The optimal subsidy unit price according to total budget restrictions was examined using demand and supply functions. The demand curve was created based on data from installation subsidies in Saitama municipalities and Web-based questionnaires.

The results recognized the existence of an optimal value of the subsidy unit price for maximizing the number of installation applicants. However, even when the subsidy unit price was low, the number of applications was not less than the number budgeted by the municipalities. It was considered desirable to set the subsidy unit price low enough that the number of applications was not less than the budgeted number.