2019/10/01 by Alejandro Datas, Datas, Alejandro, Alba Ramos +3 · 2 citations
Energy · Engineering · Environmental Science · #Solar Thermal and Photovoltaic Systems #Smart Grid Energy Management #Energy and Environment Impacts
paper · pdf · doi:10.48550/arxiv.1910.07028
This article assesses whether it is profitable to store solar PV electricity\nin the form of heat and convert it back to electricity on demand. The impact of\na number of technical and economic parameters on the profitability of a\nself-consumption residential system located in Madrid is assessed. The proposed\nsolution comprises two kinds of heat stores: a low- or medium-grade heat store\nfor domestic hot water and space heating, and a high-grade heat store for\ncombined heat and power generation. Two cases are considered where the energy\nthat is wasted during the conversion of heat into electricity is employed to\nsatisfy either the heating demand, or both heating and cooling demands by using\na thermally-driven heat pump. We compare these solutions against a reference\ncase that relies on the consumption of grid electricity and natural gas and\nuses an electrically-driven heat pump for cooling. The results show that, under\nrelatively favourable conditions, the proposed solution that uses an\nelectrically-driven heat pump could provide electricity savings in the range of\n70-90% with a payback period of 12-15 years, plus an additional 10-20%\nreduction in the fuel consumption. Shorter payback periods, lower than 10\nyears, could be attained by using a highly efficient thermally driven heat\npump, at the expense of increasing the fuel consumption and the greenhouse gas\nemissions. Hybridising this solution with solar thermal heating could enable\nsignificant savings on the global emissions, whilst keeping a high amount of\nsavings in grid electricity (> 70 %) and a reasonably short payback period (<\n12 years).\n