The burning question
Matthew Woodcock explains how – and why – Highfield & Brookham Schools are using a woodfuel system to heat their buildings
Added 28 February 2014 | Highfield, Brookham, biomass, woodfuel, heating, boilers, education
Posted by Dave Higgitt
An opportunity to access huge cost savings, fight climate change and engage students in the drive to live responsibly and protect our world for future generations – with evidence of these benefits on display at Highfield & Brookham Schools in West Sussex, there’s little wonder that independent schools across the UK are increasingly exploring woodfuel as a heating solution.
Wood is our oldest source of heat and when sourced from sustainably managed woods and forests provides a ‘carbon lean’ fuel. Woodfuel is available as logs, chips or pellets which can be burned in sophisticated, modern stoves or boilers suited to particular situations.
What’s the bottom line?
The building types and energy requirements at schools and colleges can be ideal for accessing the considerable financial benefits of a woodfuel system. At Highfield & Brookham Schools, for example, replacing 20 oil boilers with a state-of-the-art woodfuel alternative is saving £100,000 each year in oil purchase alone.
Soon the schools will also begin receiving regular payments (which will continue for 20 years) from the government through the Renewable Heat Incentive scheme as a reward for generating ‘green’ energy. And with a reduced spend on heating system maintenance added to the equation, the economic case for woodfuel is very clear.
A greener school
For Highfield & Brookham Schools, the bottom line benefits are a welcome bonus rather than the main driver for switching to woodfuel. The co-educational boarding schools’ ethos is to minimise environmental impact wherever possible, and to instil in pupils an awareness of their environment and how to care for it. The new woodfuelled heating system has a key role to play.
Forestry Commission research has demonstrated that using locally grown, sustainably produced woodfuel in efficient boilers instead of fossil fuels can reduce overall CO2 emissions by 90%.The Highfield & Brookham Schools system is forecast to reduce the schools’ CO2 emissions by 288 tonnes each year. According to government conversion rates, this is the equivalent in emissions of driving the width of the sun (or more than 864,000 miles) in a medium-sized car.
Sourcing woodfuel
The environmental and cost benefits are greatest when the woodfuel used has been grown and produced locally as this uses only small amounts of fossil fuel and time to harvest and transport the wood. The supply of high-quality wood chips, pellets and briquettes from local suppliers has improved significantly over the past five years. According to recent studies, the UK woodfuel industry is now worth more than £25m to the UK’s green economy – supply is stable and growing.
At Highfield & Brookham Schools, woodfuel is being sourced from the most local supply possible: the schools’ estate. To help ensure a reliable and sustainable supply, the Forestry Commission has helped the schools to bring their woodlands into good and environmentally responsible management. By managing the woodland, the Highfield & Brookham Schools team has not only increased the availability of wood produced for use as woodfuel, but felling some trees selectively is improving the woodland habitat and allowing trees and wildlife to thrive – a real bonus to students.
The circular energy system that this approach creates has been incorporated into Highfield & Brookham Schools’ curriculum. Pupils have been fascinated as they are able to see first-hand the entire cycle from responsible woodland management and harvesting to use in the woodfuel system that heats their schools.
Regardless of whether schools are creating their own woodfuel or sourcing it from local firms, it is essential that it meets quality standards, so that maximum cost and environmental benefits can be achieved. Fuels should conform to a recognised standard, such as the European CEN standards, the HETAS Quality Assured Fuel (QAF) standard and ENplus for pellets. Schools can find advice and details of accredited installers at www.biomassenergycentre.org.uk.
Which woodfuel system to choose?
Highfield & Brookham Schools are using woodchip boilers in their system because it allows them to source fuel from their own woodland, and offers the most cost-effective system for their circumstances. The energy centre includes two discrete boilers supported with thermal stores (large highly insulated hot water tanks) which together allow the boilers to be run at optimal efficiency – just like your car, woodfuelled boilers are most efficient when run at steady loads, regularly changing loads reduce efficiency considerably. The heat is then distributed to the school buildings through highly insulated underground pipes
The Highfield & Brookham Schools system has been tailored to work best for the schools’ demands. It’s a design that has been carefully selected and refined through extensive research and consultation with experts and other woodfuel system users. There are, though, a range of options that independent schools can consider.
Modern wood-burning technology is very efficient, from single-room heating through to much larger-scale community projects. Selecting the right system and fuel types are important considerations when designing a wood heating system to secure the greatest environmental and cost benefits. Wood pellet boilers, for example, can be ideal for structures or sites where space is at a premium (generally the infrastructure will be cheaper but the fuel more expensive), whereas woodchip boilers are better suited to sites with larger heat loads which are less constrained by space (infrastructure is more expensive but the fuel cheaper).
A key point to remember is that while the infrastructure associated with effective woodfuelled systems can be considerable, it has a very long lifespan: the boiler supporting West Dean Estate’s system has only recently been replaced after more than 20 years.
Transferring to wood heat
The process of transferring from oil to woodfuel heating at Highfield & Brookham Schools has been a smooth one, something that their team puts down to comprehensive research and careful planning. Before embarking on the project, they gained plenty of expert advice, not least through a tour to Austria organised by the Forestry Commission.
With a clear understanding of the opportunities and considerations thanks to the research process and a thorough feasibility study, Highfield & Brookham Schools worked with a specialist mechanical and electrical company to design a system that would meet their needs. The payback against capital spend has been calculated as between six to eight years, meaning that cost benefits after that time will be effective savings that can be reinvested.
Installation of the system began in the summer holidays in 2012, and was carefully planned to ensure that any disruptive activities (such as the trenchwork for the district heat network and integration of the new systems into school buildings) were undertaken during holidays. The entire system was fully operational by Easter 2013, when an open day highlighted the interest and support of pupils, parents and staff alike.
The benefits of using a woodfuel heating system in an independent school are clear and the support is in place for schools looking to explore the opportunity further. Please visit www.forestry.gov.uk/forestry/infd-6pggqror email Matthew.Woodcock@forestry.gsi.gov.uk to find out more about how the Forestry Commission can support you. With energy prices rising and environmental impact set to remain high on independent schools’ agendas, now is the time to take action.
Matthew Woodcock is partnership and expertise manager at the Forestry Commission W: www.forestry.gov.uk