Case Studies

Case Studies

These pages contains a wealth of information on ‘whats happening’ with wood fuel in the Surrey Hills. There are a range of cases studies and news items to choose from.

Historic Home Installation

Wood pellet boiler installed in 16th Century Thursley home

This 22 KW Italian Extraflame wood pellet boiler provides heating and hot water for a 500 year old 3 bedroom cottage in Thursley.

Home owner Julian says:

“It’s fantastic – I was on Economy 7 before and it’s reduced my heating bills by £500 a year. The house was originally built to be heated by wood fuel all those centuries ago, and it just feels right to go back to this way of heating – only I don’t have to worry about chopping wood!”

Wood pellets are delivered by local producer Harvest wood Fuels – based just 3 miles away – a tonne at a time in 15kg bags on a pallet.

The bags are stored in the basement where the boiler is located and are poured into the integral hopper on the boiler as necessary. To fill the hopper takes less than 5 minutes and a full hopper lasts for 2-3 days, though extra hopper storage has been incorporated which can extend this period to a week.

Julian will invest in a bulk hopper in the near future, which will allow a bulk blown delivery of two tonnes to be made twice a year, in much the same way as an oil or LNG fired boiler.

Also like these more conventional types of boiler, aside from emptying the ash in the garden once a month, the wood pellet boiler is fully automated, with a thermostatic control and automatic timer.

Large Boiler for Care Home

Local care home installs large scale wood pellet boiler

Manormead Nursing Home in Hindhead, Surrey is owned by The Church of England Pensions Board with the original building dating back to the 1920’s.

In the autumn of 2007 a new purpose built extension was opened. The builders of this extension, in line with a request by the Pensions Board, were eager to deploy some form of renewable energy on site. Many renewable technologies were considered, however biomass heating was seen as offering the most cost effective and practical solution.

Asgard Biomass was asked to provide detailed proposals for a suitable biomass heating system.

A variety of potential fuel types for the biomass boiler were explored, and it was decided that the preferred fuel would be wood pellets.

The builders design objective for the building was that a minimum of 10% of its energy consumption was from a renewable source. It was therefore decided that a 50kW biomass boiler would act as the lead boiler with back up from three 60kW gas condensing boilers.

From calculations made by the M&E engineers involved in the project this approach would mean that a minimum of 75% of all heating in the building would be from the biomass boiler. This would allow the 10% criteria to be easily exceeded.

This unit is designed to operate with an externally located fuel hopper or silo and features a fire damper, filling indicator and flexible screw control.

As installed the boiler is located in the plant room with the other boilers. A pellet store was constructed adjacent to this room and was fitted out, by Asgard Biomass, with full length sloping floors and flexible screw. This screw discharges through the joining wall into an uplift auger which deposits the fuel into the back end of the boiler

Peaslake School switched to Wood Fuel

Peaslake School pioneers Wood Fuel in Guildford

IN OUR MARCH newsletter Mark Lebus told us about the excellent progress the Surrey Hills Wood Fuel Group is making to utilise our local woodlands to generate sustainable supplies of wood fuel for commercial and domestic space heating. Mark’s company LC Energy Ltd is leading the charge with others, such as Longlyf Timber Ltd, and with the Forum playing a supporting role. With wood fuel supplies in place efforts are now being focussed on promoting the benefits of wood fuel, which include the fuel cost advantage, security of supply, improved biodiversity from better woodland management and local jobs. As with other renewables, the UK’s use of biomass for heating is lagging far behind other European countries; we hope that is all about to change.

One inspirational project that was commissioned in Guildford in April this year is at Peaslake School, which sits at the very heart of the Surrey Hills surrounded by the most beautiful woodlands. It is not a state school, but is run by the village community for their community. When the original state school was closed in 1994 Peaslake School Trust, a registered charity, was established by the village residents to keep the school open for 3 to 7 year- olds. They receive no state support, apart from funding for early years (nursery). Peaslake villagers fund, operate and manage the school, which is absolutely brilliant.

When the school oil-fired boiler needed replacing last year the Trustees decided that they would like to use wood fuel, provided they could stay within a capital cost premium over a new oil boiler of no more than £2,000. With Mark’s help this objective has been achieved. A 50 kW Gerkos pellet boiler supplied by Longlyf Timber in Tilford is installed and up and running. Wood pellets are made from sawdust (a waste product) sourced from sawmills and are delivered in bulk. A small pellet plant is being installed at Longlyf Timber and so very shortly the 7 to 9 tonnes a year of fuel that the school needs will be supplied from the Surrey Hills Wood Fuel Group by Harvest Wood Fuel, set up there to make wood pellets –a truly local, renewable and sustainable energy source. The children can now make important connections between our sensitive climate, the trees around them, diminishing oil and gas supplies and being comfortable and warm at school.

John Bannister, Transition Guildford

Shoelands Farm Estate

Wood chip system used for Shoelands Farm estate heating in Seale.

This wood chip district heating system in Seale was commissioned in December 2006. The 100 KW Talbotts boiler provides heating for 7000 sq ft offices, 2500sq ft of storage and heating and hot water for one four bedroom farm house and one five bedroom manor house; there is enough capacity to heat three more cottages.

The boiler uses 61 tonnes of wood chip per year with a moisture range between 14.3% and 19.7%. Timber, mainly chestnut coppice grown on the Estate, is stored outside for a year, with a sheet of silage plastic covering the top only.

Chipping takes place 4 or 5 times a year where the timber is chipped directly into old silage trailers. A day’s chipping produces 10 trailer loads of wood chip which is stored adjacent to the boiler ready to be loaded by tractor front end loader into the hopper. One hopper load of wood chip lasts about four days.