Sizing and economic analysis of a solar photovoltaic micro power system for Arundel Boarding house with or without net metering.

Abstract

In this research, a hybrid solar photovoltaic micro power system that would improve the power supply reliability to desirable levels at the least possible cost was designed for Arundel Boarding House in Mount Pleasant experiencing drastic load shedding and yet accommodating University of Zimbabwe students. A solar powering system required to improve electricity supply reliability, was sized using a Microsoft Excel simulation model for a hybrid solar power system, designed using solar geometry and radiation relationships and also using dimensionless parameters. All the size variables where expressed as dimensionless parameters in order to generalize the system such that it would be useful to other places with the same economic conditions, solar radiation and load pattern. The program takes into account solar climatological data like solar radiation, ambient temperature and variability of the electrical load and then computes the energy, supply, reliability, LCOE as output. The reliability level was set and the combination that got the least LCOE was noted using the graphing method. Cost advantages of net metering (a billing mechanism that credits individuals who generate off-grid electricity for the electricity they add to the grid) were compared. The Excel model revealed that 5 of A/A0 (dimensionless parameter for array area) required supplying power of 15.46kW, 15.46kW inverter power and 76.81kWh of battery capacity for a daily demand load of 74.212kWh. In the project it was shown that with net metering the least LCOE resulted in 24.0c/kwh whereas without resulted in 29.1c/kWh and showed that the use of net metering can reduce significantly the cost of the power system. The Grid-tied photovoltaic powering system was found to be more cost efficient when utilizing the net metering strategy LCOE as 24c/kWh at a reliability of 99%. Hence the government should implement/legislate the net metering strategy to improve the reliability of supply of grid electricity.