Szentlörinc Heat Plant, Hungary

The project was a 3,1 MW geothermal heat plant in the town of Szentlörinc in southwest Hungary. Geothermal Development in Szentlőrinc started in 2008 with the aim of replacing the existing fossil fuel-based system with renewable energy for space heating and hot potable water. The drilling of a successful production well was completed in September 2009. The target was a fault in crystalline basement rock that was encountered at a depth of about 1800 m. The second well drilled was a successful reinjection well, used to return the geothermal fluid back to the reservoir. Upon completion of each well extensive well tests were carried out, to test both the characteristics of the wells and the geothermal reservoir itself. Mannvit commenced on an EPCM project for PannErgy to deliver a fully functioning geothermal heat plant in late 2009. On-site construction was commenced in July, 2010 and completed with a successful commissioning and start-up of the geothermal system in December, 2010.

The new geothermal loop replaces an earlier natural gas based boiler system that produces 3,1 MW of thermal energy to ensure the heating and hot water demand for most of the homes in Szentlorinc, and has excess capacity for further expansion.


  • Project Management
  • HSE
  • Well siting
  • Well design
  • Well site geology
  • Drilling supervision
  • Well testing
  • Geothermal reservoir modelling
  • Environmental modelling
  • Mechanical, electrical and civil engineering
  • Licensing
  • Tendering of contractors
  • Evaluation of tenders
  • Project / Procurement / Construction management
  • Construction supervision
  • System commissioning
  • EPCM project management
Production well
86 °C 
Fluid temp
55,000 GJ 
Production capacity

The developer of the program is the privately owned PannErgy of Hungary, with Mannvit supplying technology, engineering and geosciences consulting, procurement, site supervision and project management (EPCM). Since project initiation in 2006, Mannvit completed geological and geophysical testing of potential geothermal areas all across Hungary, as well as evaluation of potential geothermal areas in Hungary (database contains 7,000 wells), followed by detailed measurements and research at specific locations to determine actual well locations. These included audio magnetotelluric surveys, magnetotelluric soundings, and gravity surveys of 460 km of MT lines and 1900 gravity stations. Mannvit then performed an integrated interpretation of all geological and geophysical data in southwest Hungary, resulting in detailed well siting reports on the 27 most favorable areas. Site-specific work included well design and drilling supervision as well as EPCM delivery of complete systems for operation.