The heat is on: ‘Co-generation’ combined with renewables is a crucial component of low-carbon future

11 May 2011

The supply of heat is largely ignored in the energy and climate change debate, even though heat represents nearly half the world’s final energy consumption, a new report by the International Energy Agency (IEA) states.

According to the latest figures, heat represents 47% of energy consumption, compared with 17% for electricity, 27% transport; and 9% for ‘non-energy use’ (which covers fuels that are used as raw materials in different sectors, such as oil used to make plastics).

Oil, coal and gas account for more than two thirds of the fuels used in meeting this significant demand for heat, which causes significant levels of CO2 emissions into the earth’s atmosphere, while using up these important resources.

Electricity and heat from same fuel

In order to address this energy and climate change challenge, the IEA report demonstrates the benefits of co-generation – the simultaneous generation of both electricity and heat from the same fuel.

The heat which is produced through co-generation can be used to supply both residential buildings and industry. Heat can be distributed through district heating (DH) networks, which are hot water or steam pipes that generally run underground.

While the fuel for co-generation (also known as Combined Heat and Power) varies greatly and can include anything from coal to biomass, natural gas, or nuclear material, the report stresses that using renewable sources of energy is an obvious solution towards meeting a low-carbon energy future at the same time as addressing the supply of electricity and heat.

“While electricity supply is a crucial aspect of the energy debate and will continue to remain as such, decision makers increasingly realise that heat supply is a sizeable part of the energy system,” write Jayen Veerapen and Milou Beerepoot. “If the system is to be decarbonised, changing the heat supply will also need to be considered. Both co-generation and renewables are technologies that are relevant to heat supply.”

The authors cite examples of countries which are already using co-generation with different renewable sources of energy. For instance, Iceland, Italy, Germany and Turkey are using co-generation with geothermal energy (energy available as heat emitted from within the earth’s crust), where heat is delivered to district heating grids.

Action required now

The report, Co-generation and Renewables: Solutions for a Low-Carbon Energy Future, observes that co-generation is attractive to both policy makers and private users and investors because it delivers a range of energy, environmental and economic benefits, including:

  • Dramatically increased energy efficiency. (Something is more energy efficient if it delivers more services for the same energy input, or the same services for less energy input);
  • Reduced CO2 emissions and other pollutants – even more so when the synergies with renewables highlighted by the report are factored in;
  • Increased energy security through reduced dependence on imported fuel;
  • Cost savings for the energy consumer; and
  • Beneficial use of local energy resources (particularly through the use of waste, biomass and geothermal resources in district heating and cooling systems), providing a transition to a low-carbon future.

Download Co-Generation and Renewables: Solutions for a Low-Carbon Energy Future for free.