Designing Ecological Habitats - Gaia Education

stirling engine : efficient Heating for tHe ecovillage 145
Euro), subsidies/support for the
heating station of 2,570,000 DKK
(343,000 Euro), subsidies for the
pulsating heating of 97,000 DKK
(13,000 Euro), and membership
payments of 645,000 DKK (86,000
Euro). The running costs are mainly
fuel (139,000 DKK, 19,000 Euro),
while miscellaneous costs (operation,
maintenance, and administration)
are in total per annum 83,000 DKK
(11,000 Euro).
Technical Description
The heating station includes a 185 kW wood pellet boiler, a 160 kW woodchip
boiler handling up to 40% humidity in wood chips, a Stirling engine
of 35 kW electric and 115 kW heat, a 70 cubic meter woodchip storage
made to accommodate the tipping of lorry with chips, a 10 cubic meter
wood pellet storage made to blow wood pellets into, and an 8 cubic meter
heat storage tank (hot water). The distributed heat network is made of preinsulated
double plastic pipes (see right), 2 x 50 mm for main lines and 2 x 16-
25 mm for connections to individual houses. The energy demand in 2007-08
(one year) was 617 MWh including network losses inside each group of
houses. Total network loss was 52 MWh (8%) in the network of the heating
cooperative (between house groups).
Links with National and Eu Policies
The Stirling engine is connected to the grid as an independent power
producer. We paid only additional connection costs at installation. The
Stirling engine will receive a feed-in tariff of 0.75 DKK (0.10 €) per kWh.
This is according to Danish legislation that implements the EU Renewable
Electricity Directive.
Description from INFORSE-Europe database, see: http://www.inforse.
org/europe/success/SU_About.htm
Gunnar is Mechanical Engineer (MSc) and the European Coordinator of the International
Network for Sustainable Energy (INFORSE) and energy political coordinator at the Danish
Organisation for Sustainable Energy (OVE). Gunnar has lived in Hortshøj eco-community
with his family with two children since 1994. He is also Chairman of the Cooperative Energy
Association at Hortshøj.
The energetic centre
of the ecovillage: The
power station housing
the Stirling engine.