Technical and Economic Potential of Solar Energy on Rooftops: A Case Study at Lampang Rajabhat University, Thailand

Abstract

This paper presents an assessment of the potential of solar rooftops, and an analysis of the feasibility of investing in rooftop photovoltaic systems for the buildings at Lampang Rajabhat University. The ArcGIS solar radiation analysis tool was used to prepare the solar radiation maps. The derived solar radiation values were then used to evaluate the viability of investing in rooftop photovoltaic (PV) systems, considering factors that included Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PB) through project analysis and evaluation. According to the analysis, 23 buildings could be fitted with a solar rooftop, and 4,106 solar panels would cover 8.29% of the roof area. Southerly oriented pitched roofs had high solar radiation; nevertheless, slopes steeper than 40° reduced the radiation. Flat roofs with solar panels that were oriented southward and inclined at around 15° were found to be effective. When the PV-potential value was compared with the PV output value, a 0.19% difference between the values was observed. After we adjusted the PV-potential value in the PVpotential areas, the solar energy potential was determined to be 1,540,389.14 kWh per year. This potential could result in a 42.73% reduction in the total electricity cost at the university. Furthermore, the system's financial and environmental analyses revealed that the discounted PB would be 9 years and 6 months, with a reduction of 791.44 tCO2eq/year. These findings could be used to guide the university in developing a policy about the installation of a rooftop PV system, reduce fossil fuel consumption, and increase self-generated clean energy. These indicators are critical milestones for the university toward becoming a green university and achieving the Sustainable Development Goals