Question:

Can we put a cost on the advantages of cogeneration compared with conventional thermal, gas or coal-fired power stations?

Answer:

Remember that the principle of cogeneration consists of generating electricity and heat at the same time from a single energy source. The most frequently used fuel is natural gas, but biogas from decomposed household waste in landfills can also be burned. Waste incinerators should, at some point in the future, be connected to a heating network and a turbine. Cogeneration represents primary energy savings for heat and electricity of 15 to 30% (17% on average) in relation to the generation of an equivalent amount of heat in a boiler and electricity in an electric power station. The maximum efficiency of the most efficient electric power stations – presently gas or steam turbine facilities – is 55%, which means that 45% of the fuel’s energy is dissipated in the form of heat. Cogeneration can recover a large proportion of this heat, thus boosting energy efficiency to a maximum of 85%, compared with 30% for a conventional thermal plant that generates electricity or heat, but not both at the same time.