TALLINN – Last year, the Geological Survey of Estonia started a pilot project on the use of geothermal energy, which will explore the potential of geothermal energy in different parts of Estonia and as part of which two geothermal pilot plants will be built and cooperation with Finland started.
Aivar Auvaart, project manager for geothermal energy at the Geological Survey of Estonia, noted that normally, low-temperature geothermal energy is derived in Estonia from a depth of about one meter by means of ground source heat pumps.
"The potential of medium and high temperature energy, which lies deeper than 500 meters from the Earth's surface, has not been studied more thoroughly in Estonia, but in Finland it is widely used for the production of thermal energy," Auvaart said in a press release.
For example, in Kolho near the city of Jyvaskyla, and in Koskelo near Espoo, underground energy systems employing wells with a depth of almost 1.4 kilometers have an output of about 1.5 gigawatt-hours of heat per year.
"In Vantaa, at Ruskeasuo, a 2.5-kilometer borewell is currently being drilled, with the help of which the heating needs of 180 apartment buildings in the surrounding area are intended to be covered. In addition to heat, that station will also be used for district cooling," Auvaart said.
In addition to these existing solutions, a well three kilometers deep is being drilled in Tampere, which will be extended to nearly eight kilometers if the novel drilling technology performs well.
Exploration and deployment of geothermal energy is important because it is a renewable energy source that helps to reduce greenhouse gas emissions. As a result of the project, it will become clear whether geothermal energy is a technically suitable and economically viable energy solution for heating, cooling and energy storage in Estonia.
According to Auvaart, the project will explore the usability of geothermal energy applications in Northern Estonia, as well as the potential for the use of mine water and seawater thermal energy applications.
"We will study the feasibility of setting up pilot plants, prepare the technical design and commission two pilot plants. We will also analyze the legislation and the necessary authorization procedures, and set up a database of borewells," the project manager said.
"We hope that the efficiency of the test plants will encourage Estonian construction and real estate companies to use geothermal energy more widely," he noted.
Increasing the energy efficiency of buildings is an important topic across Europe. Buildings account for almost 40 percent of the European Union's energy consumption, so it is important to increase the number of nearly zero-energy buildings and to set up support schemes to finance the energy efficiency of buildings. Geothermal energy has been highlighted in the European Union as one of the renewable energy sources that can be used to increase energy efficiency.
The research project of the Geological Survey of Estonia will run until the end of 2024, the budget of the project is 3.8 million euros and it will be financed using funds received from the sale of greenhouse gas emission credits.
Geothermal energy is derived from the natural heat of the earth, which results either from the accumulation of solar energy in the ground or from the radiation of heat from the depths of the Earth's crust. Geothermal energy is efficient and environmentally friendly, more than twice as efficient as conventional air source heat pumps. A heat pump using geothermal energy takes advantage of a constant ground temperature of between 10 and 15 degrees Celsius for both heating and cooling.
The life span of geothermal energy equipment is 20-25 years with normal maintenance. The life span of the contour placed inside the borewell is 40-60 years. According to different estimates, a heat pump using the Earth's energy can save 30 to 60 percent of heating and 20 to 50 percent of cooling costs compared to conventional heating and cooling systems.