MicroCHP power station with Stirling Engine

In this award-winning LIFE project, results from a long-term test (30,000 hours) of a microCHP unit with Stirling Engine are reported in layman terms. A 3 kWe/15 kWth system is evaluated, serving a 42,000 kWh heat / 8,800 kWh electricity demand in a semi-detached house:

• Compared to a gas condensing boiler, the CHP unit costs 7500 euro more.
• The system runs in heat-driven mode, feeding its electricity into the grid. Annually, 9882 kWh is generated, i.e. more than the home's demand.
• The house continutes to take its electricty demand of 8800 kWh from the grid. I.e. in winter, the house will be a net generator, and in summer, a net consumer.
• The payback on investment is 8 years, mainly through electricity feed-in, tax incentives and a 'CHP Act Bonus'.
• No CO₂ measurement is reported, although the 'potential reductions are 33% to almost 50%'.

Comments MicroCHP with Stirling engines is an emerging but not yet mature technology. It the a potential for mass application, but not in the setup described in the report. Making the electricity from microCHP units dispatchable increases its potential, but requires the units to run in electricity-driven mode. A heat of 44,000 kWh is significant. This is either an old, poorly insulated home, or a very large, modern house (at 100 kWh/m2.a, it would be a 440 m² dwelling, four times the average European size).