Clinton Devon Estate
Generating a local market for the estates’ lowest quality product. Clinton Devon Estates’ new woodchip enterprise is helping make sustainable sense of its forestry operations. As you meander up the long drive with landscaped parkland on each side towards the Rolle Estate Office, the HQ of Clinton Devon Estates (CDE), you’d be forgiven for expecting to be signposted to a small manor house or some other aged building that’s been part of this Grade 1 listed landscape for centuries. So for many it’s a jawdropping moment when they actually get to the HQ itself. Instead of a solidly square historic façade you’re faced with the curves, timber cladding and glass of a beautiful and futuristic building.

It’s built mainly from local, sustainably- sourced materials and has just about every eco-friendly feature you can think of, including a ‘green’ roof planted with sedum that reduces rainwater run-off, an energy saving lighting system and a passive cooling design which stores
night air and replaces the need for traditional air conditioning. At the heart of this award-winning building is a woodchip boiler, which heats it using timber from the woodlands in east and north Devon managed by CDE. It was knowing this new building was on its way that inspired the first steps towards the estate’s newest enterprise as a woodchip producer.

According to John Wilding, forest manager for Clinton Devon Estates since 1997, the new building is a statement about land management in the 21st century. When he joined CDE as forest manager 12 years ago John couldn’t have predicted how his job would change to embrace wider environmental areas. Today, as well as running an extensive forestry operation across three estates, John is also involved in river management, renewables, anaerobic digestion, a small bio-diesel operation and a growing woodchip enterprise.

“The management of the estate has changed to become much more integrated,” John continues. “The woodchip enterprise is a great example of that.” Early plans for the new Rolle
Estate office were drawn up in 2004. It was known then that the new eco-friendly building would be heated by a woodchip boiler and so John Wilding set about researching and visiting similar installations around the country and looking at how the estate could fuel it.

Working in partnership
Discussions with local company Forest Fuels of Shebbear, which has seven regional depots and specialises in brokering fuel supply contracts, confirmed that the estate needed a depot approach with its own dry, efficient production. Finding a wood source was no problem at all. CDE has almost 2,000 hectares of woodland in north and east Devon made up of a mixture of commercial conifers and native broadleaved species. Previously, low quality timber was being hauled up to north Devon or Wales to be made into chipboard. Because of haulage costs this was being done at a financial loss – not only making no business sense, but, with the road miles, it wasn’t making environmental sense either.

Now low grade wood, usually less than 7” in diameter, is turned into woodchip. This means that the estates’ woodchip enterprise has increased its woodland productivity too, as 12-15 per cent of the material being brought out now would previously have been left on the forest floor as it was too small for traditional bulk uses. “In Devon we’ve got lots of woodland in steep or awkward locations,” explains John Wilding. “On these sites where winching is required there will always be a role for manual fallers. We use FJ Deimert from Petrockstow who provides a first-class service and understands our requirements well.

Our more accessible sites are worked by harvester with direct production undertaken by D&K Harvesting and standing sales by Euroforest which uses Mike Jones. It’s important to be working with contractors who are flexible and capable of delivering a high finish, especially as we now also want the low grade material brought out to be chipped.” A third of the woodland managed by CDE is in east Devon on the Clinton and Beer Estates and is planted with a mix of Corsican pine, Douglas fir and larch. The remaining two thirds is on the Heanton Estate in north Devon where the soil is wetter and heavier, and so the mix of wood is different with Douglas fir, Sitka spruce and larch.

On all three estates chipwood from regular thinnings is stacked on-site to air dry until moisture levels are around 30% – readily achievable over the course of a summer.

A risk worth taking
Despite a ready supply of wood to convert into fuel, setting up a commercial woodchip operation with a view to supplying their own needs and those of external clients was still a very speculative move for CDE.

Five years ago woodchip boilers were being talked about more than being installed. But for John Wilding it was a ‘no-brainer’. “At the very least we’d have a sustainable way of disposing of low quality timber, an eco-friendly way to heat our new building and, more importantly, long-term fuel security. “But we knew there was a sound commercial opportunity too. In Europe these woodchip boilers have been used for years very successfully and on a mass scale, heating office blocks, residential complexes and whole communities. It was just a
matter of time before they caught on in the UK and I figured that having a readily available local fuel supply would do a lot to encourage installations in the South West.

It could have been a chicken and egg situation, but we decided to lead from the front and help make it happen.” A successful bid in the first round of the Bio-Energy Infrastructure Grant Scheme run by Defra enabled CDE to convert a former beef fattening unit into a woodchip processing depot a few miles away from the estate HQ. Processing began in October 2006, well ahead of the opening of the new HQ a year later, to ensure a strategic reserve of fuel. In the external bays on three sides of the depot there’s room to stack a total of 500m³ of dry timber.

The building is used to store dry woodfuel before dispatch to customers. A Heizohack chipper is contracted in from partner company Forest Fuels. Initially a manually-fed model was being used, but, now that production volumes have increased, a lorry-mounted crane-fed Heizohack has helped quadruple production in the same amount of time. At present the Heizohack is processing around 300m³ in just over a day which keeps the estate and its clients going for a few months. The plan is to increase this to 1-2 days each month.

In 2007-08 woodchip production was only 200m³ as it was being done for estate use only. In 2008-09 this increased to 1000m³ to meet the requirements of the estate’s first external customers, though the top capacity being aimed for in about four years’ time is 8-10,000m³ in a season.

Currently the size of woodchip being produced by CDE is G30, which is aimed at smaller boilers that can’t use larger grades of fuel. However, the depot has the capacity to process and store larger grades of woodchip if the client base develops to include enough larger boilers to warrant it.

Growing client base
A number of substantial clients are now being supplied by CDE’s woodchip enterprise via partner company Forest Fuels who broker and manage the contracts, including Devon County Council which converted to a woodchip boiler to heat County Hall in Exeter in April this year. Their fuel requirement is forecast to be around 850m³ per year.

For most clients, woodchip is delivered in high capacity tipping trailers. But for Paignton Zoo’s alligator swamp, which is heated by a woodchip boiler to maintain 25ºC all year round, it’s delivered in a rigid eight-wheeler 30m³ at a time as the site’s infrastructure isn’t able to deal with a larger vehicle.

At present CDE is supplying customers up to 50 miles away in Dorset, but it’s expected that, as more woodchip boilers are installed, more processors will set up to provide local fuel sources for local customers. CDE’s delivery area will reduce which, according to John Wilding, is as it should be. “In line with the estates’ commitment to promoting a sustainable local economy, the woodchip operation needs to be as eco-friendly as possible, which means minimising our delivery area. What we want is an increase in local boilers, not haulage miles.”
The boiler heating the 5000 square foot Rolle Estate office is a 49kW Binder from Austria, provided by Woodenergy from Oakford, Devon. It uses 75m³ of woodchip to heat the building through the winter but produces just 1½ wheelbarrow loads of ash, demonstrating just how efficient this technology is at converting wood into heat.

“Essentially, what the woodchip enterprise has done for our forestry operation is generate a local market for our lowest quality product,” says John Wilding. “It’s really helped us make sustainable sense of what we do and is going to provide us with significant commercial and environmental advantages as we move into the future.”

Clinton Devon Estates may have 400 years’ experience in forestry, but that heritage is certainly not weighing heavy as it forges ahead with its contemporary, relevant and economically viable forestry operation – thanks in no small part to the
new woodchip enterprise.
Veronica Newport