130Kw Woodchip Heating System
The owner decided to install a woodchip system to replace an ageing and inefficient oil fired boiler that serviced the main communal buildings at the site.
At the same time, it was decided to extend the system to provide hot water to 12 chalets and heating to the indoor swimming pool. The existing gas-fired boilers have been retained as a backup for the swimming pool heating and a new, but much smaller, oil fired boiler was installed for the remainder. These were used briefly when an experiment with a different fuel type proved unsuccessful but otherwise have not been required.
Fuel Supply and Chip Handling
Dunster designed and implemented the conversion of an existing outbuilding to house the boiler and accumulator tank and sourced the second-hand grain silo and potato handler for the chip store and loading system. These were adapted to allow deliveries using a standard tipping trailer and have been a great success. There is no requirement for any chip handling by St Audrie’s staff or equipment.
System Design and Installation
The system was designed as a baseload boiler to provide 90%+ of heat and hot water with a combination of oil and gas boilers to deal with peak loads. In the event, the 3,000-litre primary thermal store and 2,000-litres satellite thermal store have sufficient reserve that the backup boilers have not yet been required.
Benefits
In addition to the major financial benefit of becoming independent of oil and gas prices, the installation has further enhanced St Audrie’s environmental credentials.
February 2011
Supply of heating and hot water to chalets, restaurant, communal buildings and swimming pool at holiday park (St Audrie’s Bay website)
130kw ETA Hack woodchip boiler installed in an adapted outbuilding with a 3000-litre accumulator tank.
The boiler is expected to use about 100 tonnes of G30 woodchip per annum, producing around 350,000Kwh of heat. Seasoned woodchip fuel is bought in from local suppliers.
A 80m3 fuel store was created by installing a second hand galvanised grain silo adjacent to the boiler. Woodchip is transferred direct from this to the boiler by auger and rotary arm agitator. The store is loaded with woodchip by use of an adapted 8m potato elevator allowing fuel deliveries to be made using a standard tipping trailer. Refilling of the chip store occurs approximately every 2 weeks with standard loads of 25m3 although the store is of sufficient size that larger deliveries could easily be accepted less frequently. An additional benefit of this system is an integral drying floor which allows a fan to blow air through the chips if moisture content exceeds 30%.
The system received a 40% grant under the Bio-Energy Capital Grants Scheme. It is expected to transfer to the upcoming RHI scheme.
Fuel savings are still being determined as the boiler has replaced a range of oil, gas and electric systems, however, the reduced fuel bills have already had a substantial impact on the financial viability of many of the club’s activities.
Estimated at 110 tonnes per annum.
Our 90kw ETA Hack wood chip boiler suffered water damage in late 2014. Dunster Biomass Heating was the only company that could fix the issues without costing me new components. What we have learned is simple. Experience is key! When there is an unusual problem you need more than a guy with a manual – you need a company with the expertise, ability and willingness to solve the problem!
