Exploiting Biogas
Like natural gas, biogas can be used to generate heat and power, as a vehicle fuel, or in homes for heating and cooking. The methane in biogas is well suited to use as vehicle fuel, since the exhaust gases from combustion contain only water vapour and carbon dioxide.The efficiency of biogas-fuelled energy generation varies depending on whether combustion plants produce heat or power, or a combination of heat and power (CHP). In producing heat alone, efficiency levels of 90% are possible, but where only electricity is generated efficiency levels remain much lower, at around 35%. In CHP efficiency levels totaling 85% are typical, consisting of 35% electrical energy and 50% heat energy.
Local use
Most of Finland’s biogas energy facilities are small CHP plants producing heat and power for use on a local scale. Some smaller plants only produce heat. In heating plants biogas is burnt in boilers, but in CHP plants gas motors or micro-turbines may be used.The exploitation of landfill gas is often hindered by the remote locations of landfill sites with regard to energy users, but solutions to improve the viability of exploiting landfill gas are being sought actively.
The biogas produced in wastewater treatment plants is largely used to generate energy to run the plants’ own processes such as the aeration of aeration basins.
The Finnish authorities are currently considering whether feed-in tariffs will in future be paid to encourage the production of electricity from biogas and other renewable energy sources.
