Energy

Designing homes to conserve energy and use it efficiently, from sources that cause least environmental harm.

Micro-combined heat and power (micro-CHP) systems

Micro-combined heat and power (micro-CHP) units are small power generators, similar to a boiler, that generate electricity and produce waste heat that may be used to produce hot water. They are not common in New Zealand.

The hot water produced by micro-CHP units may be used for:

  • domestic hot water supply
  • reticulated hot water heating such as hydronic embedded floor heating or radiator systems.

Micro-CHP units typically use gas as their fuel, and have a far higher level of efficiency than gas-fired power stations. Models produced for houses are about the size of a dishwasher. They can produce 7.5–14 kW of water heating energy and 1 kW of electricity.

The best location for the unit is in a garage or basement against an outside wall and as close to the hot water cylinder as possible.

Schematic fuel efficiency diagram for a micro-CHP unit 
Schematic fuel efficiency diagram for a micro-CHP unit

 

 

Schematic of wiring for micro-CHP unit 
Schematic of wiring for micro-CHP unit

 

 

Schematic of a hot water supply and hot water heating system using a micro-CHP unit 
Schematic of a hot water supply and hot water heating system using a micro-CHP unit

 

 

 

Updated: 22 February 2022