"When faced with steamrolling technology, you either become part of the technology or part of the road"

- Lowell Bryan

​A Consultancy to Small Scale
​Cogeneration Markets

Applications for Microcogeneration Products

As one would imagine, the best applications for small scale cogen are directly related to the amount of heat and electricity they produce. A rule of thumb regarding the relationship between heat and electricity is as follows: Internal combustion engine units produce three times the electrical output. Therefore a 5kw(electric) unit will generate about 15kW (1kW=3412Btu) of heat. A Stirling engine unit can produce up to six times the amount of heat to electricity. Fuel cells vary, but a good estimate would be 1.5-2.0 times the heat out to the electrical output. Microturbines are in the range of four times the heat/electric ratio.

Given this information, one can determine that engine based systems would be best for generating heat, whereas fuel cells would be best for generating electricity - they also have the highest electrical efficiencies - 30% to 50% vs engine systems in the 15% to 25% range.

Typical applications for small scale cogeneration are:

  •  Residences (for smaller systems in the 1.5 to 3.0kW range) Larger homes especially with swimming pools (summer heat needs) can support a 5.0kW system.
  •  Restaurants
  •  Hotels
  •  Nursing homes (high heat demand with therapy pools, laundries, and domestic hot water needs).
  •  Greenhouses and Hyponic farms.
  •  Aquatic Centers and Health Clubs
  •  School District Swimming pools that must be heated.

Considering the state of small scale cogeneration technology today, the primary use would be for heat generation. Because of that, the list above reflects applications that need heat - and when the heat is utilized, the electricity comes along as a by-product for very little cost - typically < $0.04/kWh.