Designing Ecological Habitats - Gaia Education

stirling engine : efficient Heating for tHe ecovillage 143
consisting of individual houses
developed by a local development
company. The heat supply for this
complex social mix is managed by a
heating association with status as a
‘cooperative with limited responsibility’,
and recognised according to
Danish regulatory law as a heatsupplying
entity. For the first groups
to be developed, the heating cooperative
operated on the basis of an
exemption from the obligation to
have heat supplied from the municipal
district, while in the newer developments, the heating cooperative has the
sole right to supply heat according to Danish regulation of energy supply.
The heating cooperative is managed by a board consisting of one
representative from each house group. The Board is responsible for the
financial affairs of the cooperative, and for extension projects, etc. Work
on the Board is voluntary; the cooperative as a whole employs a paid
accountant. Sometimes, however, board members are paid for work
related to new developments. This has been the case for the preparation
and installation of the Stirling engine and for the new development
utilising pulsating heat supply. A consulting engineer has been advising
the Board on new developments using the Stirling engine and pulsating
heat supply.
The heating station operates automatically, while adjustments, general
maintenance, and the solving of smaller problems is done by a group of
volunteers, one or two from each of the house groups. While the work is
voluntary, in some house groups the chores are divided, so that the person(s)
involved with the heating station are not having other obligations in the
group during that period. A ‘chimney sweeper’ has the overall responsibility
for the operation of the heating station. When the station is in operation,
he cleans the boilers and performs safety checks every week or every second
week, depending on the season.
Development and Current Status
Until 2002, the heating was provided solely by a wood pellet boiler; however,
in 2002 it was decided to upgrade the heating station with a wood chip boiler
and a Stirling engine for combined heat and power production. The Stirling
engine was installed in 2007-2008, but due to technical problems was not
fully operational until later. By the end of September 2009, total power
production was just above 1000 kWh. After a number of improvements,
including measures to reduce vibrations and noise, the testing is now
ongoing. We expect automatic operation soon, including automatic
exchange between operation and stand-by modes.
Comfortable solarenhanced
life at
Hortshoj ecovillage,
Denmark.