Designing a hybrid wind and solar energy supply system for a rural residential building

The aim of this project was to design a hybrid wind and solar energy supply system for a rural residential building in order to satisfy its energy requirements. The system under consideration included the hot water service, the space heating system, and all the power requirements involving both electricity supply and a storage system. The optimum design was obtained by performing a costbenefit analysis for each of the individual systems. The monthly average daily energy consumption for the dwelling was found to vary between 19 and 36 kWh. The hot water system was designed to be based on flat plate collectors with a back up LPG (liquefied petroleum gas) tank. The optimum hot water hardware included 3 flat plate collectors, a 315 L storage tank and a 135 L auxiliary LPG tank. The large dimensions of the house were the limiting factor when investigating the feasibility of a solar powered space heating system. Use of very large windows made space heating a very difficult and expensive task. The high capital cost of a totally solar power system far outweighed the benefits of such a supply. Hence, it was decided to use LPG or wood for space heating. The electricity supply design was based on the building's demand schedule which during summer was 13 kWh per day and in winter it was 9 kWh per day. The power supply system was designed to be comprised of five 80-W photovoltaic (PV) modules and a 2.5 kW output wind turbine. However, the total cost of the final design was found to be much higher than connecting to the grid if the intangible benefits to the environment (eg, reduced green house gas emissions) are not quantified and are not taken into consideration. Copyright , Manchester University Press.