| Energy
John Rennie & Sons combines AD with Wolf Power
Systems CHP plant for more efficiency
By Jacob de Mol, Sales International, Wolf Power Systems.
new combined
heat and power
(CHP) plant will
help John Rennie
& Sons (Farmers)
Ltd generate
renewable electricity. Running off
biogas from an existing anaerobic
digestion (AD) plant, the expected
output is 550kW, of which 500kW
will be exported to the national
grid. The rest is used to run the
facility.
A
“We have managed to reduce
our fertiliser bill by 90% and
have gone carbon neutral”
The CHP plant was built by
Dreyer & Bosse, part of Wolf
Power Systems, a pioneer in
combining heat and power
generation, at Gask Farm in Turriff,
Aberdeenshire, an arable and pig
farm run by John Rennie & Sons.
Gask Farm has already been
operating an AD plant for 10 years,
using about 15,000 tons of
www.farmingmonthly.co.uk
feedstock, consisting mostly of
food waste and abattoir material,
with some of the farm’s own pig
slurry used as well. The AD
process produces 67% methane
and 32% carbon dioxide. The
methane has so far powered two
230kW engines and one 110kW
CHP plant (also Dreyer & Bosse
technology). The new CHP plant
will be more efficient and have
lower running costs. Having
already worked with Dreyer &
Bosse technology for over ten
years, John Rennie & Sons liked
the reliability of the company’s
engine and didn’t consider
anything else.
Anaerobic digesti