Assessing the benefits of implementing micro-CHP systems in the UK

Abstract

The feasibility of applying combined heat and power rationale to individual homes is discussed, with particular reference to the transient variations that occur in domestic requirements for heat and power. Predicted energy-cost savings, based on simulations employing 1 min demand profiles, are presented for several prospective micro-CHP systems. The effects upon energy-cost savings of prime mover capacity and efficiency, heat-recovery efficiency, central-heating boiler efficiency, and the unit price for exporting electricity are assessed. For various configurations of a nominally 1 kW_e micro-CHP system, reductions of 16-39 per cent in annual energy expenditure are identified. Carbon savings per average home of around one tonne of CO₂ per annum are predicted, but actual savings will depend strongly upon transient heat-and-power demand variations, the operating mode, capacity and efficiency of the micro-CHP system, and upon the import/export interaction that the household has with the electricity distribution network. If the carbon-reduction potential of this single technical fix is to be maximized, further research attention needs to be given to define preferred implementation strategies for micro-CHP systems in the UK domestic sector.