Opportunities for utilization of stand-alone hybrid (photovoltaic + diesel + battery) power systems in hot climates

There is a growing awareness that combustion fuels are a limited resource and burning of these fuels is the principal cause of air pollution, and possibly environmental warming. This recognition is elevating interest and activity toward the development and application of alternative/renewable sources of energy, such as solar energy to displace some of the use of fossil fuels. In this context, Saudi Arabia being enriched with fairly high degree of solar radiation, is a suitable candidate for deployment of solar photo-voltaic (PV) panels for power generation in crisis. Literature shows that residential buildings in Saudi Arabia consume about 47% of the total electric energy generated/consumed. In the present study, hourly mean solar radiation data for the period 1986-1993 recorded at the solar radiation and meteorological monitoring station, Dhahran (26° 32' N, 50°13' E), Saudi Arabia, have been analyzed to examine/investigate the potential of utilizing hybrid (PV + diesel) power systems to meet the load requirements of a typical residential building (with annual electrical energy demand of 35 200 kWh). The monthly average daily values of solar global irradiation for Dhahran range from 3.61 kwh/m² to 7.96 kwh/m². The hybrid systems considered in the present analysis consist of different combinations of PV panels/modules (different array sizes) supplemented with battery storage unit and diesel back-up. The study shows that with 225 m² PV together with 12 h of battery storage, the diesel back-up system has to provide 9% of the load demand. However, in absence of battery bank, about 58% of the load needs to be provided by the diesel system.