Energy saving is a hot topic. People are getting more and more aware of their energy usage because of continuously rising energy prices and awareness of the greenhouse problem. One of the most important causes of the greenhouse effect is the massive emission of carbon dioxide (CO2). CO2 is produced when (fossil) fuel is burned, for example by cars, industry and (natural gas fueled) boilers for domestic heating. Rising energy prices and the need for CO2 emission reduction stimulate the research for new, more energy-efficient technologies.
One of the innovative, energy-saving domestic appliances is the micro Combined Heat and Power (µCHP) [1] >. µCHP appliances produce, besides heat, electricity with a total overall efficiency comparable to conventional high-efficiency boilers [1,2], which is around 90%. Energy is saved because the heat (a rest product of electricity production) is used. Heat produced in central power plants is mostly wasted, resulting in a maximum efficiency of 55% [2]. > Replacing a high-efficiency boiler with a µCHP appliance causes a slight increase in natural gas usage, but the electricity import decreases. The benefit for an average Dutch family is a CO2 emission reduction of 1000kg and Є200 saving on the energy bill annually [2]. An average family currently causes an CO2 emission of 5000kg due to electricity and gas usage and 7700kg in total [2,3]. Households together are responsible for 20-25% of the total CO2 emission in the Netherlands[3]. The figures in this article are based on a Stirling based µCHP appliance, currently the only market-ready technology. The same principles are applicable for µCHP appliances based on other technologies (e.g. fuel cells) and other heat/electricity production rates.