Micro Combined Heat and Power (micro-CHP) Systems for Household Applications: Techno-economic and Risk Assessment of The Main Prime Movers

To limit global warming and meet international environmental targets, more environmentally benign technologies must be used in the residential market. Combined Heat and Power (CHP) at the micro-scale (<50 kWe) is seen as one of the best solutions that offers simultaneous generation of both electricity and heat with high overall efficiencies using environmentally friendly fuels (e.g., biofuel, hydrogen, syngas). In this study, four major micro-CHP prime movers (i.e. Micro-gas turbine, Gas engine, Stirling engine, and Fuel cell) have been evaluated in terms of their performance and the currently available technologies and products. The most suitable options for household applications were identified using Political, Economic, Social, Technological, Legal, and Environmental (PESTLE) risk analysis and a Multi-Criteria Decision Analysis (MCDA). Fuel cells display the best environmentally friendly properties despite their price and high start-up time. Gas engines (Reciprocating engines) have the most developed technology with the fastest start-up time and high efficiencies but have vibration and noise issues. Micro-gas turbine micro-CHPs are emerging into the market with relatively cheaper prices, lower maintenance, and good start-up time. Stirling engines are fuel flexible with reasonable prices and available products. Micro-CHP systems, particularly when running on biofuels and hydrogen, provide excellent energy solutions for the future net zero buildings.