good day all.Please can anyone tell me how to obtain an estimate of the annual potential solar energy of an area, given the area (in km2) and the average solar radiation (in kWh/m2/day)? The same question also applies to wind energy for a given wind speed and area.please any print,book,journal,links etc with simple solved problems on this questions are highly appreciated.I'm quite new to the world of integrated renewable energy system (IRES) many thanks!