Estonian Geological Survey reported last Tuesday (17 October) that the energy company Steiger began drilling works in Roosna-Alliku in the Järva county in northern Estonia, aiming to drill a borehole to a depth of around 500 metres.
A test station is being established as part of the Estonian Geological Survey’s project to investigate the possibilities of utilising geothermal energy. Instead of the current shale oil-burning boiler, this station is expected to provide environmentally friendly heat to buildings connected to the district heating network, including the local kindergarten, elementary school and municipal service centre.
“The proposed test station is expected to reduce heat production cost by up to 50 per cent according to our estimations, as geothermal energy is one of the most efficient and also environmentally friendly forms of heat energy when compared to other alternatives. It is a renewable energy source and using geothermal energy heat pumps has a small carbon footprint,” said Aivar Auväärt, Head of the Department of Geothermal Energy of Estonia’s Geological Survey.
The location of the Roosna-Alliku test station was selected primarily considering the geological conditions, but having a district heating network of suitable size was also important, the Geological Survey said in a press release.
“When the borehole is completed, extra long U-tubes with distributed temperature sensors are installed in the boreholes. The system includes a measuring device equipped with a laser and a fibre optic cable that can measure temperature once in a minute at least after each metre. Such a system allows optimising the system parameters according to the changes in consumption and over time it will also provide information on the energy potential of Estonia’s earth’s crust,” said Mr Auväärt.
According to the schedule, the Roosna-Alliku test station is scheduled to be completed by next summer.
Construction of the Roosna-Alliku test station is a part of the “GEOENEST” project of the Geological Survey, financed by Estonia’s Ministry of Climate. The project’s goal is to help reach Estonia’s energy and climate policy objectives by analysing and testing the options for implementing geothermal energy. The project’s primary goal is to establish test stations based on geothermal boreholes in Roosna-Alliku and Tiskre, and to assess the implementation potential of Estonian geothermal energy based on these stations.
For high-level execution of surveys related to geothermal energy, the Geological Survey is currently also carrying out a 3-year twinning project EGT-TWINN, financed by the EU.
The project’s primary aim is to “significantly expand” cooperation and knowledge exchange with the geological surveys of the leading geothermal energy users in Northern European countries such as Finland, Denmark and the UK, the Geological Survey said in the press release.