Micro-power generation, playing a role in meeting our energy needs


matthew wilson horticulturistHorticulturist Matthew Wilson, managing director of Clifton Nurseries in London (see its environmental policy) opened a recent FT article: As countries seek sustainable replacements to fossil fuels, the debate over alternatives rages. Global electricity production at present is 68.1 % derived from fossil fuels, 10.1 % from nuclear fission and 21% from renewable energy sources, primarily hydro power, according to a 2013 report by the Fondation Energies pour le Monde”.

RE heat pump pipesAfter a critique of wind power, he turned to another renewable energy source: ground-source heat-pump technology.

Five years Simon Howard initiated a programme of measures to cut the costs of running Castle Howard. In 2009, he installed ground-source heat-pump technology. Pipes for ground-source heat pumps were installed below a lawn. Wilson explains:

“Ground-source heating works in the same way as the elements on the back of a refrigerator, but in reverse – drawing in ambient warmth from the surrounding earth or water which can then be pumped and amplified to heat the home”. He notes:

  • insulation was improved
  • incandescent lightbulbs were replaced with LEDs
  • and every room is monitored for heat and humidity, checking the performance of the system.

Dave Mann and Mo MacLeod stumbled on the remains of Howsham Mill, an abandoned 18th century watermill a few miles away from Castle Howard. Wilson continues: “A fire had brought down the roof, silt from flooding covered the floors and trees were sprouting inside. The location of the building and its propensity to flooding meant that planning permission as a dwelling would not be granted, but the couple bought the mill regardless with a view to restoring it as a small-scale, hydro-electrical plant”.

They formed the Renewable Heritage Trust to which the mill was given, and sought funding to turn the building into an education centre with the hydro-electrical plant making it self-sufficient and generating income to secure its long term future:

“Teams of volunteers helped to dig out tonnes of mud from the water wheel, wheel pit and mill pond. Original features, including the flagstone floor, were uncovered, and in 2006 a replacement water wheel was put in place. Installation of the main Archimedes screw proved more challenging, as access to the site is by a narrow, winding footpath. The team opted to use the river instead, strapping the screw to a pontoon and guiding it upstream, and then used pulleys, blocks and chains to manoeuvre it into position. In 2012, work began to restore the mill building back to its former glory, using traditional materials – reclaimed brick and slate, English oak roof beams and lime mortar – brought to the site using horse power, carts and barrows.

re howsham millHowsham Mill. Photo: Paul Miles/Greentraveller

“Externally the building looks much as it would have done when the last miller closed the door in 1947, but the “new” Howsham has thermally efficient glazing, insulation and, of course, electricity. Power generated by the mill is used to run the building, while the balance is sold to the grid, generating £35,000 per year, which helps to fund an on-site education officer. On average, the electricity generated by the mill is sufficient to power 50 homes, at a theoretical 65% maximum output.”

Wilson adds that Mann and MacLeod have gone on to install micro-systems throughout the UK and Ireland and stresses that micro-power generation, be it hydro, wind or solar, combined with ultra-efficient insulation and improved building standards, has a serious role to play in securing our energy needs.


Comments are closed.