As micro CHP the EU (2004/8/EC) 1 has defined small scale systems (less than 50 kW). These usually are applied for space and water heating to individual dwellings and small commercial buildings replacing the conventional boilers. CHP provide furthermore fuel savings, reducing as a result emitted gases and the operational cost. The systems can function in parallel to the grid exporting energy or backing it up in case of a break down. Micro CHP seems like a promising new solution with substantial growth and prospects being appreciated worldwide. Governments consider these systems as reliable solutions. Industry is developing new technologies, introducing alternative fuels and making the systems simpler and more accessible to all.
Types of engines and fuels: Micro CHP are simple systems easily installed. They require roughly the same space with a boiler and are sound insulated. The most commercial systems are the ICE (internal combustion engines) while the external combustion engines such as Stirling engines, micro gas turbines and ORC (Organic rankin cycle) systems are aiming for the biggest market share. Fuel cells are still not commercially available. Micro CHP are usually gas or petroleum fueled. However alternatives like biomass have become available maintaining high efficiencies and reducing carbon emissions to minimum levels.
How micro CHP operate: Micro CHP systems are installed more or less as conventional boilers. They have similar volume and noise regulations. External combustion engines: Most of the micro CHP systems are external combustion engines such as Stirling and rankin |