A Feasibility Study of Investment on Self Electricity Generation by Solar Rooftop System in Thailand

Abstract

The objectives of a feasibility study of investment on self electricity generation by solar rooftop system in Thailand were to 1) consider areas which are suitable for installing solar systems on the roofs' surfaces, 2) study technical aspects of installing solar systems 3) evaluate the worthiness of investing the solar system used in a household, and 4) estimate the ability in investment when the cost is changing. This study used the primary data obtained from in-depth interviews which interviewee is an engineer or a managing director supervising in the solar panel company. Financial tools were used in this study to analyze Net Present Value (NPV), Internal Rate of Return (IRR), Modified internal rate of return (MIRR), Profitable Index (PI), Switching Value Test (SVT), and Sensitivity Analysis. The result of the study showed Thailand has a good opportunity to get sunlight almost all of the year from 09.00 A.M. to 03.00 P.M. Consequently, solar roof housing system would be suited to Thailand. Furthermore, the investment in solar roof housing system could be divided into 2 cases. To begin with the first one, on-grid inverter system that supplies the generated power to the grid and power to the load. The other one is grid interactive power system which has a backup battery to support the load even during a power failure. The solar panel which is the most suitable for home using was Poly Crystalline solar panel which its sizes of installation were 2,000 watt, 2,500 watt, 3,000 watt, and 3,500 watt. Furthermore, the result from using the financial analysis tools found that the direct electricity consumption method or On-grid inverter system was worth for investment in all production capacity. Similarly, Grid interactive power system was worth for investment in all production capacity except production capacity which is 3,500 watt.