This paper conducts analyses and proposes solutions for reducing mismatch between renewable energy (RE) production and electrical demand from a 150 m2 single-family house. The RE options are photovoltaic (PV) and micro-wind turbine. This paper mainly focuses on the situation when grid feed-in is not available, but a brief economic analysis with grid feed-in is also conducted at the end of the paper. This paper specially investigates the influence of electrical storage in batteries and thermal storage in a domestic hot water (DHW) tank with suitable RE-DHW recharging strategies. The simulation results show that the recharging strategy of excess renewable electricity to a DHW storage tank with one day's DHW volume is more technically and economically effective than using electrical battery in reducing annual mismatch. Even without battery, the improvement in reducing mismatch can be 12.7-23.3% simply by using the RE-DHW recharging strategy. Furthermore, PV with 2-axis solar tracking strategy is not economically feasible in the Nordic climate, whereas south-facing PV with a 45^0 fixed tilt angle is recommended. Moreover, from both the energy and economic points of view, the increased hub height with multiple turbines is preferable for the application with a 6.64-16.2% improvement in reducing mismatch.
"Sunliang Cao, Ala Hasan, Kai Sir'en"
Credit: opengreendoors.blogspot.com
