Micro Combined Heat and Power (micro-CHP) generators
combine the benefits of the high-efficiency cogeneration
technology and microgeneration and is being promoted as a
means of lowering greenhouse gas emissions by decentralizing
the power network. Life Cycle Assessment of energy systems
is becoming a part of decision making in the energy industry,
helping manufacturers promote their low carbon devices, and
consumers choose the most environmentally friendly options.
This report summarizes a preliminary life-cycle energy and
carbon analysis of a wall-hung gas-powered domestic micro-CHP
device that is commercially available across Europe. Combining
a very efficient condensing boiler with a Stirling engine, the
device can deliver enough heat to cover the needs of a typical
household (up to 24kW) while generating power (up to 1kW)
that can be used locally or sold to the grid. Assuming an
annual heat production of 20 MWh, the study has calculated
the total embodied energy and carbon emissions over a 15 years
operational lifetime at 1606 GJ and 90 tonnes of CO2 respectively.
Assuming that such a micro CHP device replaces the most
efficient gas-powered condensing boiler for domestic heat production,
and the power generated substitutes electricity from
the grid, the potential energy and carbon savings are around
5000 MJ/year and 530 kg CO2/year respectively. This implies a
payback period of the embodied energy and carbon at 1.32 - 2.32
and 0.75 - 1.35 years respectively.
Apart from the embodied energy and carbon and the respective
savings, additional key outcomes of the study are the evaluation
of the energy intensive phases of the device’s life cycle and the
exploration of potential improvements.