Cogeneration Definition

Cogeneration is a highly efficient and ecologically beneficial method of power generation consisting of the effective utilisation of waste heat while producing power. During this heat and power generation process, fuel energy utilisation is up to 90% with minimal losses.

In conventional (coal fired) electricity generation, for every kWh of electricity generated over 1kg of carbon dioxide is produced, and over 1.5kWh of thermal waste heat is rejected to the atmosphere.

Cogeneration Efficiencies

Cogeneration Efficiencies

This means only approximately 40%-45% of the energy in the coal is converted into electricity. In addition to this, extra losses of around 10%-25% are associated with the transmission and distribution of electricity from relatively remote power stations to end consumers via the electricity grid. These transmission losses are greatest when electricity is delivered to the smallest consumers.

By generating electricity from natural gas, one kWh of electricity only produces around 0.5kg of carbon dioxide, that’s 50% compared to coal fired electricity. There is still the 1.5kWh of thermal waste heat generated, however by utilising this waste heat, the efficiency of a cogeneration plant can reach over 90%. Further to this, because the electricity produced by a cogeneration plant is normally used locally, transmission and distribution losses are negligible.

Encompassing a range of technologies, cogeneration will always include an electricity generator and a heat recovery system. Cogeneration installations are usually sited as near as possible to the place where the heat is consumed and ideally are sized to meet the base electrical demand of the site.

How does a Cogeneration Plant Work?

What is Cogeneration?

What is Cogeneration?

Natural Gas (1) is used to power the reciprocating engine. This Natural gas source is burnt in the cyclinders to produce the power from the engine (2). The Exhaust gas heat exchanger (3) captures the heat released from the engine. Using both the heat from the Engine jacket and the exhaust gas means that Cogeneration can produce high efficiency heat. (4) The heated water goes through a heat exchanger to release the heat to a secondary circuit. This circuit (7) can then be used to heat your swimming pool, showers, domestic taps, air conditioning or any where else that heat is needed. The altenator (5) turns the power produced from the Engine into electrical power. Reciprocating engines have excellent electrical efficiency. This then gets sent to the building reducing the load on the grid (6)


  • Increased Efficiency
  • Reduced Heat Loss and Energy Wastage leading to Lower Heating Bills
  • Reduced Distribution Losses
  • Reduced CO2 Emissions and Carbon Footprint
  • Reduced Running Costs
  • Reduced Heating Bills

Cogeneration Applications

  • Hotels, boarding houses, hostels
  • Municipal heating plants
  • Industrial establishments
  • Aged Care Facilities
  • Office buildings
  • Laundries
  • Social welfare institutions
  • Water parks
  • Supermarkets
  • Urban heating plants
  • Hospitals and clinics
  • Health resorts
  • Trade centres
  • Large residential properties
  • Fitness centres
  • Agricultural establishments

Go to our Projects page to understand more areas where Goldman Energy Cogeneration systems have been used

Cogeneration Feasibility Studies

Cogeneration can be used anywhere that has a consistently high electrical load and a high thermal load. Cogeneration become feasible when the heat can be used. For more information on feasibility studies and to get a free consultation contact us at