Impact of Performance Degradation and Capital Subsidy on the Revenue of Rooftop Solar PV System

Abstract

The capital subsidy is one of the recognized techniques to promote solar Photovoltaic (PV) systems to the investors. Most of the nations have offered subsidies to investors, who are willing to invest on developing small-scale photovoltaic system to large-scale multi-megawatt system. This paper tries to analyze whether the given subsidy will have any influence on the revenue generated from a PV plant considering two studies, one is without capital subsidy, and second is with 15 % capital subsidy. The revenue generated in each case is analyzed considering the approved grid feed-in tariff rates set by the electricity regulatory commissions separately for each case depending on the plant capacity. Another known fact is that there exists performance degradation in the PV plant throughout its lifetime or age. Hence during the evaluation of revenue, the energy degradation over the PV plant lifetime i.e. 25 years is considered. Focused results for analyzing the system includes energy yields for the first year, energy yields considering degradation, yield factors, capacity factors, revenue generation, and payback periods. With the analysis on the above-mentioned parameters revenue benefits of PV systems with and without capital subsidy are discussed.