Optimal sizing of grid-connected hybrid wind-PV systems with battery bank storage

Conventionally a battery bank is used as the backup system in standalone Hybrid Renewable Energy Systems (HRES) while in grid-connected systems the grid performs as the backup during power shortage periods. For the latter, different prices of electricity during peak and off-peak hours raises a question about the cost effectiveness of using the grid as a backup. Adding a small storage system to maintain the shortage of electricity produced by renewable resources at peak hours may prove to be more cost effective backup. This paper focuses on the design of an optimised grid connected small-scale HRES, incorporating a battery bank to store electricity during off-peak periods and uses this storage to support the HRES during peak demands. This system is intended to be cost effective (taking into consideration the Feed-In-Tariff) and make building self sufficient with regard to energy use. The performance of the proposed design method is evaluated based on a case study for a typical household in UK.