Micro-CHP

What is it?  Combined heat and power (CHP), or cogeneration, is the process of generating both electrical power and useful heat from a single source. Large scale CHP, suitable for commercial applications, has been around for some time.  MicroCHP, suitable for use in the home, is a relatively new development.

MicroCHP is a microgeneration unit that generates 1kW of electricity per hour that can be used in the home, while it is providing space heating and hot water.  It has been developed to operate virtually noise and vibration free, in a casing that is no bigger than a standard domestic boiler.

• For the environment: electricity generated close to where it is to be used has fewer carbon emissions and is much more efficient.
• For the householder: saving money on electricity bills.  In addition, it may be possible to sell unused electricity back to the local grid .
• Improved security of supply by not having to rely on centralised power production

Different technologies employed

There a number of technologies that are being developed for use in microCHP.

Internal combustion engines - Baxi has a miniCHP unit for commercial use that generates 5.5kW of electricity and 12.5kW of heat.  

Free Piston Stirling Engines - Baxi's current microCHP production units for domestic use have a Free Piston Stirling Engine. 

Proton Exchange Membrane Fuel Cells - Baxi is developing micro-CHP units based on PEMFC technology which offer 1.5kW electrical output (3kW thermal output) and are currently under going extensive field trials with partners in the EU. The units will be for domestic applications and will offer high electrical efficiencies and very low carbon emissions.

Fuel options available - The miniCHP unit can use natural gas, LPG, fuel oil, biodiesel and rape seed oil.  At the moment, microCHP units operate using natural gas, but are being developed to work on other fuels including biomass and Hydrogen.