A COMPARATIVE ASSESSMENT OF SELF-CONSUMPTION SUPPORT SCHEMES FOR ROOFTOP PV SYSTEMS IN THAILAND

Abstract

The growth in the adoption of solar photovoltaic (PV) power generation systems has been accelerating around the world, contributing to the debate about the future of policy and regulation in a high distributed energy resources future. Thailand is one of the leaders in solar investment in Southeast Asia. It has recently shifted its policy framework from subsidizing power export through feed-in tariffs toward a policy that is focused on supporting self-consumption of PV electricity. There are three possible forms of self-consumption support scheme: net metering, net billing, and self-consumption only. Net metering and net billing are electricity policies to assign compensation to excess electricity generated from the prosumers’ sources, particular in rooftop solar PV system. The design elements on new self-consumption scheme from perspectives of various stakeholders together with the assessment of economic feasibility of rooftop PV system under self-consumption schemes can help to ensure successful implementation of the policy. It is important to analyze the possible impacts of rooftop PV system on distribution network system. This dissertation consists of three main components: economic feasibility analysis, technical analysis, and stakeholders’ perspectives analysis. First, this study assesses the economic feasibility of residential and commercial sectors on rooftop solar PV systems under Thailand’s self-consumption scheme, net metering with rolling credit and buyback scheme, and net billing with real-time buyback scheme. These three schemes are compared using 3 indicators: Net Present Values (NPV), Payback Period (PB), and Internal Rate of Return (IRR) to assess the feasibility of rooftop solar PV investment for consumers. To supplement the understanding of selected schemes, this research assesses the technical factors that support or hinder the implementation of solar PV rooftop by reviewing Thailand’s grid code and meter requirement of rooftop solar PV installation. Third, this study investigates the perspectives of stakeholders on the detailed design options of self-consumption schemes for supporting rooftop solar PV system installation. When combined the outcomes of stakeholder’s perspectives, the result also shows that most of stakeholder groups prefer a strong desire to compensate for excess generation from rooftop PV system in the form of net metering. This finding corresponds to the economic feasibility analysis, which indicate that net metering with rolling credit and buyback is economically feasible for both residential and commercial sectors. Finally, this dissertation suggests policy recommendations for each group of stakeholders in order to increase their understanding on how to contribute to a sustainable scheme to scale up rooftop solar PV installation for both residential and commercial customers in Thailand.