In Denmark, Dall Energy has been
selected by local heating utility
Sorø Fjernvarme A/S to supply a
turnkey combined heat and power
(CHP) plant to the town of Sorø.
Full sustainability is reached based on
a circular economy concept, avoiding
dependency on fresh water, arable
land and inorganic fertilizers. The Life
Cycle Assessment (LCA) performed
on the demonstration plant showed
an energy return on investment
(EROI) of 4, changing the paradigm
of effluent treatment from energy
consumer to net energy exporter.
The 12 MWth and 1 MWe plant will
primarily be fired on local woody
green waste and will replace a fossil
gas fired facility as part of the goal
to have 100 percent of the district
heating from renewable sources.
"It will be the first district energy
plant in Denmark that will use local
woody green waste from gardens
and parks as the main fuel", said
Jens Dall Bentzen, CEO of Danish
biomass gasification and combustion
technology providers Dall Energy.
Recycling, materials, nutrient– and energy recovery
Sorø Fjernvarme is local district
heating owned by Affald Plus.
AffaldPlus is a joint municipal waste
management company owned by six
municipalities (Faxe, Sorø, Næstved,
Vordingborg, Slagelse and Ringsted) in
south and west Zealand.
Recycling and recovery of resources
is a key priority for AffaldPlus which
also includes green waste such as
hedge- and roadside trimmings, grass
cuttings, bush and tree “lop and top”
and pruning from private gardens,
public parks and other urban green
areas.
This fuel is currently being supplied to
third-parties, but will in the future be
used for the new CHP plant in Sorø.
Turnkey delivery for Dall Energy
The scope of Dall Energy delivery
comprises of a biomass gasification
furnace and a hot oil boiler, including
all associated auxiliary equipment
such fans, piping, a fuel feeding
system, ash handling system,
electrical and control systems. Dall
Energy is responsible for turnkey
delivery of the equipment, including
design, procurement, installation and
commissioning.
"We've seen from our other energy
plant installations that they can use
such fuel as woody green waste."
"However, this is the first project
contract that we have signed
explicitly with the assurance that it
will be possible to fire the plant with
100 percent woody green waste", said
Jens Dall Bentzen.
The contract was awarded to Dall
Energy in Q4 2019, and the plant is
scheduled to be handed over for
commercial operation during the
summer of 2021.
Significant savings for heat customers
The plant will be designed for
operation on 100 percent green
waste but can also utilise regular
woodchips, providing extensive fuel
flexibility.
"We estimate that on an annual
basis, about 80 percent of the fuel
will be green woody waste with the
balance made up of forest biomass
and woodchips", said Tommy Fer.
The plant efficiency will be up to 110
percent (LCV based) depending on
the fuel quality. Once commissioned,
the plant is also expected to provide
energy cost savings to district
heat customers along with the
environmental and climate benefits.
According to AffaldPlus, an average
household can expect reduced
annual heating costs of almost
25 percent.