Page 163 - Sustainable Cities and Communities Design Handbook

140 Sustainable Cities and Communities Design Handbook

Geothermal and Heat Pumps
The town of Frederikshavn is located on potential geothermal resources, which
may be included in the project. The resources can supply hot water at a
temperature of approximately 40 C. However, the temperature can be

increased to district heating level by the use of an absorption heat pump, which
can be supplied with steam from the waste incineration CHP plant. It has been
calculated that an input of steam of 13.3 MW in combination with a
geothermal input of 8.7 MW can produce 22 MW of district heating. The
steam input will decrease the electricity production from the CHP plant by
only 1.3 MW and the heat production by 11.9 MW. Marginally, the absorption
heat pump has a coefficient of performance (COP) of more than 7.

The geothermal plant in Thisted, Denmark, produces 15.4 GWh of heat per year. (Thisted
Varmeforsyning).

Additional compression heat pumps may be applied to utilize the exhaust
gases from the CHP plants and the boilers supplemented by other sources,
such as waste water, as already included in the plans for 2009. A potential of
10 MW th output is included by use of a heat pump with a COP of 3.

Combined Heat and Power Plants and Boilers

The project includes a biogas CHP plant of 15 MW and efficiencies of 40%
electricity and 55% heat. The rest of the heat production will be supplied from
a biomass boiler burning straw with an efficiency of 80%.