Micro-Cogeneration

Micro-cogeneration, also called micro combined heat and power (microCHP), is an extension of the well established idea of cogeneration to the scale of the home or small building and is used to heat water or spaces and produce electricity. Cogeneration is the principle of capturing and using the waste heat emitted by heat engines powering other energy applications (http://en.wikipedia.org/wiki/Micro_combined_heat_and_power). For example, diesel generators may use biodiesel as the fuel for the engine which would not only power a generator for electricity, but which also could use an exhaust gas heat exchanger and heat recovery system to heat internal spaces (http://www.electricitygeneration.co.uk/biodieselelectricity.html). In cogeneration systems, the efficiency of energy conversion can be increased to over 80 percent as compared to an average of 30 to 35 percent for conventional fossil fuel fired electricity generation systems (Onovwiona and Ugursal 2004). This increase in energy efficiency can result in lower costs and reduction in GHG emissions when compared to the conventional methods of generating heat and electricity separately. Micro-cogeneration systems use conventional (natural gas) or alternative (biomass or fuel cells) fuels to power engines and turbines so a system’s operation is only as “green” as its power supply. In Humboldt County, a food waste digester runs a cogeneration facility, a good example of symbiosis of technologies. See “Energy Efficiency Programs.”

Citations:

Onovwiona, H.I. and V.I. Ugursal. 2004. Renewable and Sustainable Energy Reviews 10(5): 389-431.