Coppice Resources - Experience Growth
Coppice Resources
  Coppice Resources  

Case Studies

Enlarge Image 1 - 2
District heating from biomass at Hexgreave Hall, Nottinghamshire

Hexgreave Estate in Nottinghamshire is now nearing completion of a £3m programme to restore and convert the Hall, buildings and estate with backing from the European Regional Development Fund and Nottinghamshire County Council. The Hall and adjoining coach house have been fully refurbished to provide exclusive office suites whilst refurbished cottages and newly built properties provide live/work homes in the vicinity of the Hall.

In 2005 an Austrian manufactured 300kWth Binder biomass boiler was installed and commissioned as the central feature of the district heating scheme for the estate. Fuel for the boiler, in the form of wood chip, comes from 16ha of SRC planted in 2000, 8ha having been harvested in 2005 and 8ha in 2006 plus wood from the 400ha estate’s woodland management programme. A further 30ha of SRC is due to be planted in 2007. The 46ha of SRC plus small amounts of woodland residue will provide sufficient fuel for the boiler. Not only does the SRC provide home-grown fuel for Hexgreave Hall, it also adds to the visual diversity of the estate landscape and will add significantly to the biodiversity of the local area. The SRC is planted, managed and harvested on behalf of Hexgreave Estate by CRL.


Enlarge Image 1 - 2
CRL header for SUNY/Case New Holland

In 2005 CRL were asked by the State University of New York (SUNY) and Case New Holland (CNH) to develop an SRC header to fit a CNH FX series forage harvester. The original CRL header was designed to fit the Claas Jaguar forage harvester and therefore used a mechanical drive system. For the CNH harvester a hydraulic drive system had to be developed whilst all the other header features remained unchanged.

The development of the new header was supported by SUNY and CNH and, after trials in the UK, it was ready for export to the United States in April 2006. Development of the export market was supported by (TESF) funding from the Sheffield Chamber of Commerce



Enlarge Image 1 - 2
Development of CRL SRC harvester

During the late 90s, when the first commercial SRC sites were due for harvest, trials of a number of different harvesters proved there was no suitable machine available for use in UK conditions. In 1998 development began on the first tractor-mounted CRL direct-chip header. It was required to cut two rows in one pass, provide a clean cut to all stools and cut no higher than 10cm above the ground surface. By 2001, following three years R&D and with support from ETSU and Claas, the self-propelled CRL header was in use mounted on a Claas Jaguar 860 forage harvester. The Jaguar was a standard model with a few modifications including strengthened feed rollers, under machine protection and wide tyres for minimum ground disturbance

The header has cut stems up to 15cm diameter at the base and 12m in height although the ideal stem specification for efficient harvesting is up to 8cm diameter and 8m height. The output of the harvester depends on the size and nature of the SRC crop being cut but the target is 125odt per day. The chip produced can range from 4mm to 34mm in length, the standard being 30mm The CRL harvester has recently been sold to an SRC grower in Northern Ireland and will be shipped in March 2007. A new header is being built to fit CRL’s recently bought Claas Jaguar 900 forage harvester and this SRC harvester will also be in use in March 2007. Interest in the CRL SRC harvester is now coming in from across the UK and from around the world, wherever SRC is grown or being considered as an energy crop.


Enlarge Image 1 - 2
SRC harvesting using Swedish Bundler

One of the harvesting methods trialled by Arbre Energy during the harvest of their first commercial SRC sites in December 1998 was the Swedish Salix Maskiner Bundler. The willow stems were cut at the base with a chain saw, fed up an elevator and onto a table where they were then fed transversely into the bundling mechanism. Each bundle was wrapped, cut to length by a saw blade and dropped at the side of the machine. Harvesting was slow as the machine had to stop each time a bundle needed to be cut and off-loaded. The bundles were 2m long by 0.6m diameter, wrapped in polypropylene mesh and had an average weight of 136kg. During the trial it soon became apparent that the Bundler was having difficulty in dealing with UK SRC. Swedish SRC is generally planted as a pure monoculture i.e. large blocks of one variety and, due to the shorter growing season, it does not achieve the level of growth SRC grown under UK climatic conditions does.

Because of these difficulties, Chris Mell and Fred Walter of CRL, with the approval of Salix Maskiner, took the Bundler to carry out major strengthening of the metalwork and some of the harvester’s mechanisms. Due to the predicted high costs of whole stem bundle or bale harvesting, Arbre decided to trial direct chip harvesting during the winter of 1999/2000 and the machine chosen for the work was the CRL chipper harvester as Arbre had had input into the header design in the form of the following requirements:

The height of cut must be below 10cm; the stools must be cut cleanly and with no damage; all stems must be cut and there should be no ground damage in the form of rutting or compaction within the plantation.

This led to the development of the CRL harvester in use today.

Copyright Coppice Resources Ltd. All rights reserved 2009.