Increase of the Efficiency of the Neubrandenburg Geothermal Heating Plant Through Surplus Heat Storage in Summer

Abstract

The Neubrandenburg Public Utilities run two energy generation plants representing the state-of-the-art, thus improving considerably the ecological balance through economically profitable operation. The Neubrandenburg Geothermal Heating Plant (GHP) supplies heat to a residential area with 15 MW connected load. Since 1997, power and heat are moreover supplied to the high-temperature district supply system from a combined gas and steam turbine process. In both generation plants, there exist problems in summer regarding the exploitation of the potential. ï The power plant would require a very big heat store to shift surplus heat into the winter season. Therefor, the surplus heat will be stored in the aquifer of the GHP. ï Due to low thermal water temperatures, additional heating with gas driven units (absorption heat pump, boiler) is required in the GHP. The surplus heat of the gas and steam turbine plant increases the geothermal deposit temperature up to 80 ?C. Under the conditions in the thermal water system ï thermal water flow max. 100 m?/h ï heat storage temperature 80 ?C 12,000 MWh/a are stored in the 4.2 MW ATES. 8,500 MWh/a can be reproduced in winter.