Cogeneration, also known as combined heat and power (CHP), can simultaneously produce heat and electricity from the same facility. Cogeneration is a particularly effective solution since it can make full use of the heat produced as a by-product of power generation.
This heat is captured in a number of ways and is used to:
- feed and boilers;
- supply multi-dwelling units, hospitals and municipal buildings;
- provide utilities for industry.
Electricity can be generated using piston engines that usually run on natural gas. It can also be produced by gas turbines (using technology similar to that employed in jet engines) or steam turbines (using steam from boilers, geothermal energy or waste energy from industrial processes). In each case, the heat is recovered to produce steam or supply hot water to heating networks and buildings.
The benefits of cogeneration
Cogeneration offers a whole array of benefits:
- significantly reducing CO₂ emissions by avoiding the need to produce heat and power separately;
- back-up regarding power supply;
- enabling energy savings of between 10% and 25% compared with systems that generation heat and power separately;
- providing state-of-the-art facilities that offer a continuous supply of electricity, unlike the intermittent supply of energy from wind and solar sources.
Methane management – benefits for mining and local authorities
In Poland almost 900 million cubic meters of mine gas (methane) is released in hard coal mining per year, of which only 24% is used, mainly in the energy sector. The emission of methane into the atmosphere contributes to the greenhouse effect: reducing methane emissions by 1 tone is equivalent to avoiding the emission of 21 tones of CO₂. The use of gas for energy and heat production significantly reduces the emission of harmful substances to the atmosphere.
Dalkia Polska Energia is one of the leaders in the use of methane for heat production. Over 30% of the heat generated at the Dalkia heat and power plant in Katowice is generated from mine methane.