ABSTRACT
The UK government’s target is to make all new homes zero carbon by 2016. Is this a credible objective? In the case of photovoltaic cells (PVs) an average household would need about 10m2 of cells mounted on a south-facing roof to be able to meet a reasonable fraction of its electricity needs.This is high grade energy. But a substantial part of a household’s energy needs are met in the form of low grade energy for space heating and domestic hot water. Economically, the installed cost of solar thermal panels is only one quarter that of PVs.The average house does not have the roof area to provide for both solar electric and solar thermal energy. At the present state of technology, it would be difficult for the average home to be zero carbon. Even the most energy efficient house will still need an additional source of energy either in the form of offsite electricity or from a combined heat and power (CHP) unit from a local grid or power from the national grid.
