An EU-funded project is building a 22 megawatt (MW) geothermal-biomass heating plant at Sieradz, in the Łódzkie region of Central Poland. The project includes drilling a hole down which hot water extracted from the earth can be reinjected into the ground after being used to provide heating. Local residents will thus have a reliable heat source, which will reduce the use of coal-fired boilers and cut annual CO2 emissions by some 40 000 tonnes, thereby bringing public health and environmental benefits. In addition, the plant will lower energy production costs.
Combined geothermal-biomass heating plant under construction in Sieradz, Poland
- 14 June 2022
“The example of Sieradz shows how ecologically important and economically promising a source of geothermal energy is. It will eliminate, to a large extent, the emission of harmful substances into the atmosphere, while providing the city with a stable heat supply.”
Hot water will be extracted through a production hole more than 1 500 m in depth that was drilled prior to the launch of the current project. Creation of the injection hole entails drilling to a depth of almost 1 900 m.
In a separate project, a high-efficiency co-generation module is being built to support the operation of the heating plant, particularly in winter. It will use biomass, in the form of woodchips, as an energy source and will have electricity and heat production capacities of 0.9 MW and 1.1 MW respectively.
Positive findings
Almost half of Poland’s territory has underground water deposits that could potentially provide geothermal energy. Local authorities are interested in investigating this potential, and financial support is on offer from both EU and national funding programmes. Investment in geothermal resources is increasing with a view to exploiting these resources wherever they are found.
Drilling of the Sieradz production hole was part of the city’s efforts to better understand the geological structure of the area and improve management of minerals and groundwater. The drilling made it possible to explore and document the local thermal water resources. The findings were promising – the water yield from the resources is 249 m³ per hour and the water temperature is 51.8 °C.
Two uses
The geothermal water will be used in two ways. Firstly, it will pass through gasketed plate heat exchangers to transfer heat to water in the pipes of a district heating network. These heat exchangers contain plates separating warm and cold fluids. As the fluids flow through the plates, heat is transferred between them.
The water in the pipes will be heated to a maximum temperature of 52 °C, while the geothermal water will be cooled to about 49-50 °C. Secondly, the geothermal water will supply heat to two lithium bromide absorption heat pumps, each with a capacity of approximately 10 MW.
Total investment and EU funding
Total investment for the project “Construction of a geothermal-biomass heating plant in Sieradz with injection hole Sieradz GT-2” is EUR 13 411 359, with the EU’s Cohesion Fund contributing EUR 7 028 325 through the “Infrastructure and Environment” Operational Programme for the 2014-2020 programming period. The investment falls under the priority “Low-carbon economy”.