Abstract To solve global warming issues, the whole world is moving toward establishing the post-2020 climate regime. As part of its efforts, each country is promoting the reduction of its greenhouse gas emissions by setting up its national carbon emissions reduction target (CERT). Therefore, this study proposed the optimal PV system implementation strategy to achieve the national CERT for educational facilities. The mono-crystalline silicon PV system is economically profitable (NPV25 ≥ 0 and SIR25 ≥ 1) and superior by 14.57% to the poly-crystalline silicon PV system in terms of its national CERT achievement rate. Also, its national CERT achievement rate was estimated within the range of 16.98–607.56% by type of educational facility and by region. Thus, the budget for PV system implementation should be determined by type of educational facility and region. This study can help policymakers establish the optimal PV system implementation strategy in the central government (i.e., the Ministry of Education in South Korea, the U.S. Department of Education, and the Department for Education in the U.K.) and local governments (i.e., the Seoul Metropolitan Office of Education, the New York City Department of Education, and the City of London Local Education Authority).