Member state HUNGARY-2
Case study Bóly
Description Bóly is a small agricultural town with 4000 inhabitants. In 2006, a district heating project is born : 1500 m deep production well was drilled. The wellhead temperature is 84°C in this well. A 2.5 km long pipeline transports hot water. At the end of the pipeline, the thermal water is 76°C, which is reinjected under the ground. With the help of this system, the town gas consumption has been reduced by 800 000m3 per year.
Region>City>location Southern Hungarian Transdanubian Region
Owner municipality
Operator municipality
Installed capacity
( MWth)
Installed geothermal capacity 2,5 MWth
DH length
Inhabitants connected Municipal and entrepereurial buildings are connected in a village of 4000 inhabitants
Design of the DH Three stages cascade system
subsurface and surface
technical schemes
Attached in the doc file
significant pictures if any Attached photo in the doc file
 Operating Temperature of the DH 80-34oC
Temperature of the geothermal ressource
(production – injection)
84oC reservoir temperature, 28-34oC injection temperature
Heat Pump
if any
(power in Mwe and COP)
Production of heating and/or cooling 20500 GJ/y
Dates of begining and end of construction 2007-2008
Planing of the operation
(from pre-studies to full completion)
3 years
Investement for
geothermal well
0,8 mio€/2 wells
Investement for
geothermal heating station
0,33 mio€/15 stations
Investement for
DH network and substation
0,3 mio€/7 km pipeline
(banks, funds, PPP…)
EU based subsidy 60%, municipality 40%
Amount of Subsidies
if any
0,85 mio €
Difficulties faced cascade system
Administrative permits water management operating permit
Cost of the produced MWh ~9.3€/MWh (incl. investment cost, support and 25 years operation)
Cost of the MWh sold  
Comparison with fossil energies  ~80% of gas price
Final energy cost structure  
Taxes no
Pay back 11.8 years
Innovation if any Three stages cascade system
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