ABSTRACT
High-performance houses need very little heat, but a considerable amount of electricity, which is all the more significant when considered in primary energy terms. In this chapter, we assume that 1 kWh of heat from natural gas requires 1.14 kWh of primary energy, while 1 kWh of electricity requires 2.35 kWh of primary energy to produce. For this reason, it is highly attractive to consider ways of producing electricity from a renewable source, onsite. A photovoltaic (PV) system is an expensive investment, but promises trouble-free electricity production over a long life time.
