Tullynessle & Forbes Community Hall wood fuel case study

Reasons for changing to woodfuel

The previous heating system used radiant and electric panel heaters that were operated on demand. These were expensive to run and so were only turned on when needed, this often left the hall temperature very low, which was uncomfortable for hall users.

Research and investigation found woodfuel to be the best option over ground source heat pumps, due to the favourable costs of installation.

System features and benefits

The new woodfuel system provides constant background heating which serves to keep the hall at a more reasonable temperature for users, as well as protecting the fabric of the building against damp.

Originally pellets were delivered in bulk and manhandled into the fuel store. For ease of use, the store has now been adapted to accept blown pellet deliveries.

Wood fuel supply

Wood pellets are bought direct from a producer 30 miles away, and delivered directly into the hopper via a pneumatic blower attached to the delivery vehicle.

Blown truck loads often have a minimum delivery of about 5 tonnes. One tonne load bags delivered on a pallet are a cheaper way to receive pellets, but require onsite handling machinery. Buying in bags can cost up to twice the price of buying in bulk.

Dust socks or filters on the exhaust pipe or a layer of rubber fixed to the back of wall of the pellet store will reduce dust build-up through pellet break up.

Installation issues

The building was completely renovated in 2008. Wall and under floor insulation were improved to ensure increased heat retention, further helping to reduce heating costs and energy consumption.

The boiler and fuel store are located within the existing storage area of the hall, this meant that no additional boiler house construction was required.

Two universal fitting delivery pipes into the fuel store are required to accept blown deliveries (the second pipe allows excess air to escape).

Lessons learned

• It is important that the user fully understands the cleaning requirements of the boiler to maintain output and reliability
• Delivery methods need to ensure dust creation is kept to a minimum
• Secure a local fuel source as soon as the development is conceived
• An internal fireproof hopper can add extra costs to a project - make sure all costs are identified and included in the budget
• Carefully consider long-term delivery options for pellets. Blown supplies are most like current fossil fuel deliveries, with minimal input from the user
• Make sure your building is as energy efficient as possible, thatproper due diligence is done and that you have a comprehensiveunderstanding of woodfuel before planning a woodfuel installation
• The availability of contractors locally to service the system is key to minimising maintenance costs
• If your fuel hopper is not big enough to take a full load of pellets and you wish to avoid buying individual bags, you are dependent for re-supply on whoever happens to be delivering pellets in your area and when
• It is difficult to predict when pellets will run out without actually checking the fuel hopper

Facts and figures

Note: figures are approximate

Please note:

Whent his woodfuel system was installed, the UK Government Renewable Heat Incentive (RHI) scheme did not exist. The RHI is now available and commercial woodfuel heating installations can receive payments based on metered heat produced for 20 years.

If this project were eligible for the RHI, it could generate up to £2,236 of income per year, based on the maximum biomass tariff of £0.086 per kWh, assuming 26,000 kWh of heat delivered per annum, this income could be combined with any savings made over displacing fossil fuels to give a very potentially attractive payback period.

Projects installed pre July 2009, or that have received public grants for their boilers from other sources (unless they have paid them back) are not eligible for the RHI.