Life cycle costing of a self-sufficient solar-hydrogen system

In a renewable energy-based system, energy storage must match the energy demand with supply. Usually a lead-acid battery is utilised as a short-term energy buffer. A system, which has a combination of an electrolyser and a high-pressure hydrogen tank for long-term energy storage, is considered in this paper. The cost intensive components are sized considering the least cost and by performing a life cycle costing of the system. The optimum battery capacity obtained is 19 kWh, which is equivalent to 2.2 days of autonomy. At present, energy storage cost in the long-term storage is found 2.16 per kWh whereas the cost goes down to 0.92 per kWh when the target cost of the fuel cell and the electrolyser is considered. Around 15–20% of the demand is supplied by the long-term storage.