System Design and Performance Analysis of a Grid-Tied Solar PV Power System in Bhutan

This paper presents system design and performance analysis of a grid-tied solar photovoltaic power system with battery backup. The system was designed to supply 10.5 kW lighting load of a library building at the College of Science and Technology in Bhutan. The performance was simulated using HOMER model. From the simulation, it was found that the PV system is able to supply more than 31% of the load in a year. The cost of PV energy generation over 25 years project life term was found to be 0.13 US/kWh which is six times higher than the current average cost of hydropower generation. The proposed system is financially not viable at the current subsidized electricity tariff in Bhutan as the payback period is more than the project life term and the net cash flow is negative.