Optimization Comparison of Stand-Alone and Grid-Tied Solar PV Systems in Rwanda

Abstract

Solar power has gained great usage in electricity generation world-wide, and stand-alone is common in Rwanda. Site visits and energy audit estimates for a typical residential house in Rwamagana district, were used to cost effectively compare stand-alone and grid-tied PV systems able to supply 7.2 kWh/day, load. Algorithms design of lifetime costs and benefits were developed, to analyse total daily energy requirements using Frequentist approaches to obtain the Kullback-Liebler solution for convexity. The Frequentist inference approaches adopted for study led to optimal solution of the design problem. Results show that stand-alone PV system needs 17 modules with US$ 15,932 initial investment and 18.1 years payback period while grid-tied PV system requires 8 modules, with US$4449 investment, and 5.7 years payback. Once government adopts smart grid technology with mature [1] feed-in-tariff, grid-tied solar power systems [2] can be used to increase electricity supply in Rwanda through domestic energy producers, because of lower initial investment costs and shorter payback periods.