Prospects of a solar-diesel-grid energy system for Silliman University, Dumaguete City, Philippines

Abstract

Many campuses have adopted the microgrid concept for decades now with backup systems that consist mostly of diesel generators. To help achieve energy sustainability and mitigate climate change, these microgrids are in the forefront in promoting renewables. This paper investigates the possibilities when integrating solar energy into the existing energy system of Silliman University in Dumaguete City, Philippines. The Philippines has abundant solar radiation most times of the year. This study looks at the components of an optimal solar-diesel-grid system along with anticipated costs and other details. The study can provide insights into the planning and implementation of similar projects as it not only highlights the most cost-effective system configuration but goes deeper into choosing a system beyond the cost of energy. The software used in the optimization is HOMER, a popular tool used in microgrid design optimization. With the minimum renewable fraction between 5% to 10%, the most cost-effective system is composed of 400 kW solar PV, three diesel generators, 200 kW converter, no batteries, and with a connection to the grid. At a minimum renewable energy fraction of 15%, the most cost-effective system is composed of 500 kW solar PV, three diesel generators, 300 kW converter, no batteries, also with a connection to the grid. Sensitivity analysis has been done to see the effect of diesel prices and the minimum renewable fraction.