2.2.15 Installation of micro-cogeneration boilers

2.2.15 Installation of micro-cogeneration boilers


Combined heat and power (CHP), or cogeneration, is the simultaneous production of useful heat and electricity from a single source, close to the point of use. Large scale CHP, suitable for industrial and commercial applications, has been available in the market for some time. Micro-CHP refers to the small-scale production of heat and power for individual commercial buildings, apartments and individual homes. These units meet the demand for space heating and hot water whilst providing electricity to supplement or replace the grid supply.


  • Carbon emissions are reduced by generating electricity at the point of use, avoiding the system losses associated with central power production

  • Heat, hot water and electricity can be produced all from the same source

  • By generating electricity on-site carbon dioxide emissions could be saved compared with using grid electricity and a standard heating boiler

  • There is little difference for an installer in replacing a standard boiler with a micro-CHP system

  • Any excess energy can be sold back to the national grid

  • Increase efficiency. CHP systems act as energy multiplier which saves energy, money and reduces carbon emissions by up to 30 percent

  • Increase reliability.  The system is independent of the grid and therefore immune to grid-level blackouts


  • It is not an actual energy source, only a means of extending energy

  • It could end up obstructing more sustainable options

  • It is only suitable where there is a need for both electricity and hot water on site

  • Heating and electricity demand must remain fairly consistent

  • Capital intensive

  • It is not long term sustainable when based on fossil fuel technology

  • Heating demand must be continuous

  • Efficiency claims are sometimes overstated since heat energy and electricity are not equivalent

Economic assessment

Unit cost for 2 to 6 kW systems is on the order of 9000 to 18000€. Payback: between 2 and 5 years. Cost savings between 20-25%.
Economic savings are generated for the user, by reducing imported electricity and by selling surplus electricity back to the grid.

References and best practices

Image gallery


Environment or playable world:

  • Residential

  • Academic

  • Offices

  • All

Carried out by:

  • Public building users

  • Owners

  • Operators

  • All

Reduce consumption of:

  • Heating

  • Cooling

  • DHW

  • Lighting

  • Electric devices

Type of driver:

  • Physical environmental

  • Contextual

  • Psychological

  • Physiological

  • Social

Time framework:

  • Short term
  • Long term

Type of measure:

  • Envelope
  • HVAC
  • DHW
  • Lighting
  • Electrical devices
  • Other
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