Pre-feasibility study of stand-alone hybrid energy systems for applications in eco-houses

In light of rising cost of fossil fuels and fears of its depletion, coupled with the increase in energy demand and the rise in pollution levels, governments worldwide have had to look at alternative energy resources. Combining renewable energy generation like solar power with superior storage and conversion technology such as hydrogen storage, fuel cells and batteries offers a potential solution for a stand-alone power system. The aim of this paper was to assess the techno-economic feasibility of using a hybrid energy system with hydrogen fuel cell for application in an eco-house that will be built in Sultan Qaboos University, Muscat, Oman. Actual load data for a typical Omani house of a similar size as the eco-house was considered as the stand-alone load with an average energy consumption of 40 kW/day and 5 kW peak power demand. The National Renewable Energy Laboratory's Hybrid Optimisation Model for Electric Renewable software was used as a sizing and optimisation tool for the system. It was found that the total annual electrical energy production is 42,255 kW and the cost of energy for this hybrid system is 0.582 $/kW. During daylight time, when the solar radiation is high, the photovoltaics (PV) panels supplied most of the load requirements. Moreover, during the evening time the fuel cell mainly serves the house with the help of the batteries. The proposed system is capable of providing the required energy to the eco-house during the whole year using only the solar irradiance as the primary source.