The Geological Survey of Finland (GTK) has released a map showing the potential for geothermal energy use in various parts of Finland.
Geothermal energy is nothing new – just taking advantage of solar energy stored in the earth, bedrock or bodies of water. The technology for exploiting it is already readily available, and in growing use.
On Thursday the GTK argued that the improvement and active adoption of such cleantech is crucial in limiting climate change. Geothermal is an odourless, invisible, renewable, reliable and limitless source of energy, it argues.
"Geothermal energy could completely replace the use of fossil fuels for buildings," says Asmo Huusko, the head of the GTK's geothermal energy department.
He says the map was released to help the public and decision-makers realise how many opportunities there are.
"There's a kind of hype going on about wind and solar energy. Sweden is more than a decade ahead of us when it comes to the use of geothermal heat, to the tune of a terawatt already," says Huusko.
Southern Finland best positioned
Huusko says there are encouraging signs, for instance Oulu's city utility is hooking up the
Kierikkikeskus museum and two schools to geothermal heating this spring – and Oulu is one of the areas with the lowest potential for such energy according to the GTK map.
It indicates that the energy is easiest and most cost-effective to exploit in southern Finland as well as Kymenlaakso and the Åland Islands. It is possible anywhere in the country, although some areas call for deeper boreholes or longer distribution pipes.
Heat wells now in use in Finland now range from around 90 metres for a summer cottage to as deep as 265 metres.
The difference depends on the depth of topsoil, the type of bedrock and its basic temperature, which varies greatly.
"In Vantaa the temperature at the bottom of a 300 metre well is around 11 degrees Celsius, whereas in Lapland it may only be two or three degrees," notes Huusko. He adds that the GTK is now calculating how much energy is available per metre of well depth in various parts of Finland. This data will be added to the online map as it becomes available.