Single Biomass System Replaces Three Oil Boilers in Domestic District Heating Scheme

Lustleigh Estate, a large residential estate on Dartmoor, comprises a main residence, two cottages, office complex and swimming pool with a pool house. The client wanted to utilise their own wood fuel supply from the Estate’s eighty acres of woodland, protect themselves against rising fossil fuel costs and reduce CO2 emissions.

They specified a biomass district heating system, which would need to replace three oil boilers. The system would have to heat five separate buildings and a swimming pool from a single boiler and link to a solar thermal array for summer hot water.

The System

Complete Biomass District Heating Package

Treco supplied and installed a single, top-of-the-range 100kW Guntamatic Powerchip biomass boiler in a district heating scheme, which replaced the three existing oil boilers. The boiler and fuel store were installed in an outbuilding located 100 metres from the main properties and all of the buildings were linked using insulated underground pipe.

In the short term, a reliable wood chip fuel supply was established through membership of the Dartmoor Biomass Cooperative. Longer term, all fuel will be sourced for free from the Estate’s eighty acres of woodland, dried, chipped and stored on site.

Treco’s complete installation, commissioning and maintenance service included;

• A top-of-the-range 100kW Guntamatic Powerchip biomass boiler.
• Existing outbuilding converted into a boiler house and wood chip fuel store.
• A 2,000 litre thermal store.
• Requirement to be multi-fuel met – runs on wood pellets, wood chips, cereals and miscanthus.
• Distribution pipework, including internal connections to plate heat exchangers.
• Self-cleaning moving step grate system improves efficiency and allows the boiler to cope with a wide variation in fuel quality. It also means that the boiler can switch between fuel types via a touch screen control panel, without the need for engineering works.
• Automated adjustment to variable heat loads; modulation from 30% to 100% capacity at 96% efficiency, reducing fuel consumption.
• Auto-ignition & de-ashing into a separate container.
• Combustion efficiency measured by lambda probe.
• Links to a solar thermal array for summer hot water.

The Renewable Heat Incentive

The Estate now has the opportunity to apply for inclusion in the Renewable Heat Incentive (RHI). This will enable them to gain payments per kWh of green heat generated by submitting quarterly meter readings to OFGEM.

These payments and the fuel cost saving will mean that the project will be not only environmentally, but financially rewarding.

The Result

Key Facts*

Fuel Consumption; 37 tonnes of wood chips, per annum. (based on 100kW boiler, in a similar application)

Fuel Cost Saving; Wood chips; 60-80% - Estate utilises own wood fuel supply. (Source Biomass Energy Centre)

CO2 Saving; Up to 98% or 44 tonnes vs heating oil. (Source; Biomass Energy Centre)

RHI Payments; A project of this size would gain an average of £10,380 every year for 20 years, index linked to inflation.

Payback Period; 4-5 years (if combining RHI income & fuel cost saving).

(*Financial information not specific to this project - figures are based on an average of several typical projects of this size. Current information on RHI payments for guidance only, not to be considered a guarantee.)

Technical Information

Guntamatic Powerchip 100kW biomass boiler system.

Specifications;

• Heat output from 92 to 100kW.
• Dimensions; 1,875w x 1,845h x 980d (mm).
• Weight; 865kg (not including 75kg stoker unit).
• Fuel; wood chips, wood pellets, cereals and miscanthus.
• Boiler output; perfect modulation at peak 96% efficiency from 30%-100% of output.
• Boiler temperature; 60-80oC (70-80oC with grain).
• Return flow temperature regulated to protect boiler.
• Water capacity; 256 Litres.
• Operating pressure; max 3 bar
• Flue diameter 180mm.
• Power connection; 400V/16Amp.
• Safety heat exchanger.

“The Guntamatic Powerchip 100 has lived up to all expectations. Quite simply it does everything it says on the box”

Darren Lucking, Lustleigh Estate  
 

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