Reasons for Changing to Woodfuel

A desire to reduce heating bills and a commitment to reducing carbon emissions were the key drivers for changing from fossil fuel to woodfuel.

Although the heating system did not need to be replaced, a dramatic rise in the cost of gas provided the financial impetus to make the change. Even when prices dropped the economic advantage still remained. An additional benefit is that wood fuel prices are more stable and predictable.

System Features and Benefits

The Eco Park is the first example of a wood fuel district heating scheme in Angus.

Heat is distributed via an underground pipe network from a single centralised boiler to each of the business units. As hot water travels round the network, it is drawn off to heat each unit as its heating is switched on. District heating schemes have a number of advantages:

Cost effective – a single boiler, boiler house and fuel store can supply many properties
Highly energy efficient due to heat recovery system
No accumulator tank is required as the pipe network acts as a mini accumulator
Delivered heat to each user is measurable and accurate, and allows individual billing

Wood Fuel Supply

Heat is provided through an energy services company (ESCo) – Angus Biofuels – under a 10-year contract.

Wood chip is delivered from a chipping plant less than three miles away, once a week in winter. every 3 weeks in summer.

Lessons Learned

Underground heating mains costs can be significant and should be costed accurately
Three-phase electricity connection cost can be a large proportion of expenditure
Containerised systems can ease design approval under local planning regulations
Early communication and support from the local authority and other regulatory bodies could reduce project delays

Facts and figures

Note: figures are approximate

Building
Heated area	650 m2
Heated volume	1,560 m3
Fabric	Lime floors, slate roof and timer frame, larch cladding with sheep wool installation
Heating System
Boiler manufacturer	Veto
Maximum boiler output	150 kW
Fuel type	Wood chips
Fuel specification	Moisture content: <30% (M30) Particle size: 80% of particles <16 mm (P16)
Store capacity	5 tonnes (15 m3)
Back-up/top-up system	Original gas system retained
Fuel Consumption, Costs and Savings
Annual wood fuel use	75 tonnes
Annual energy consumption	300,000 kWh
Annual CO2 savings	70 tonnes
Wood fuel cost	5p per kWh through ESCo contract
Fuel cost saving at 2008/09 prices	£8,000
Payback period	10 years
Installation Cost and Funding
Boiler system	£147,800
Funding source	Scottish Biomass Heat Scheme
Funding support rate	40% of additional costs of woodfuel system

Please note:

When this woodfuel system was installed, the UK Government Renewable Heat Incentive (RHI) scheme did not exist. The RHI was then opened for application and commercial woodfuel heating installations could apply to receive payments based on metered heat produced for 20 years.

If this project were eligible for the RHI, it could generate up to £19,214 of income per year, based on 300,000kWh 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.

Key benefits

Lower heating bills
Delivers on carbon reduction commitment
Close proximity to fuel supplier, helping to minimise cost
Fuel price security through 10-year ESCo contract