Development of power system designs for a net zero energy house

This study compares various power design options and their optimized schemes for a net-zero house considered in a location in Lebanon, to cover its all electrical needs while maximizing renewable energy usage and minimizing the greenhouse gases emissions. The study starts by outlining the necessary measures needed to reduce the total electrical load connected to the house through efficiency gains, after which comprehensive simulations are carried out to establish the best possible power design options with the least total net present cost and maximum renewable energy fraction, as they achieve a sustainable net-zero energy house. The simulation results show that the optimum renewable energy system for a total connected load to the house of 90 kWh/day requires a combination of PV, wind turbine, batteries, convertor and diesel generator at a total net present cost of $56,558.00 and a renewable energy fraction of 0.998. Moreover, simulations for the same connected load are carried out with different configuration of renewable energy resources and the optimum results are obtained. On the other hand, a set of simulations is performed for different areas of the house, and a sensitivity analysis is then conducted for these obtained results. An exergetic assessment is carried out to compare the efficiencies of a PV system to that of a PV/T, where water is heated by the thermal part supplied. The energy efficiency of the PV/T system is then improved by about 23% while the exergy efficiency increases by 10% with an additional cost of $8442.00. (C) 2014 Elsevier B.V. All rights reserved.