3 OverviewAIM: Inspire investment in wood-based heat generation from under managed woodlands in England, Croatia and Slovenia drawing on the experience gained in Finland and Austria.TIMEFRAME: 1 October 2008 to 31st March 2011Project Partners:Croation Forest Extension ServiceSlovenian Forestry InstituteTechnical Research Centre of FinlandStyrian Chamber of Agriculture and Forestry
4 Adding value by selling heat: Group of local farmers got together to invest in a village scale district heating system thereby adding value to the wood from their own woods by selling the ‘final’ product = heat.NOTE:Use of landform to allow delivery of woodchips by tractor and tipping trailer – i.e. existing farm equipmentSystem supplied the major village properties such as the hotel and ‘pub’ but allowed any domestic customer to join the neat network by paying a ‘connection fee’ to cover the costs of the pipework which links the property to the village heat main.Domestic property owners have option to retain their existing heating system (oil boiler?) to provide ‘back-up’ and a degree of confidence against being ‘held to ransom’ by the heat supplier. However, suspect the later circumstance is unlikely as it is to both supplier and buyers advantage to maintain a long term win-win relationship for both.Inclusion of solar thermal panels to provide the summer heat requirements of the network.
5 Keep it localSimilar to the above situation a small group of local farmers rent basement rooms in local school, install woodchip boilers and chip bunker and sell heat to the schools (junior school shown and adjacent secondary school opposite.NOTE:1. Two different sized boilers installed to allow flexibility in coping with varied heat load throughout the year – need to assess on a site by site basis whether two boilers is a cost effective option – could one boiler with an accumulator tank be flexible enough, especially if linked to existing gas or oil boilers in the heat network.2. When we asked farmers if they were looking for further situations to sell heat they explained that this system was sufficient to use all the spare wood they produced from their woods. If they looked for a further site they would need to buy wood from the open market and the economics and risk would be much greater. This situation provided a good long term local market which they were happy with
6 Use the whole resourceIn Finland medium scale woodheat systems receive their woodchips from subsidised ‘first thinnings’ (selective removal of poor form trees from woods at years old to leave better quality trees with more space to grow). Main species are birch, Norway spruce and Scots pine – relatively lightly branched compared to England and southern European woods.In many cases the whole trees are extracted and stacked to dry.However, removal of all woody biomass from a wood will result in reduced nutrients being cycled in the forest soils and a significant reduction in growth (yield class) of about 25% - as advised following Austrian research.Same applied to stump harvesting – which is carried out in some upland sites in the Scottish Borders where there is a major woodfuelled power station at Lockerbie BUT which is inappropriate for the majority of woods in SE England. This is because most woods are broadleaved and will regenerate as coppice and > half the woods in SEE are ancient, meaning they appear to have been woodland since records began and hence retain many of our native plants and animals. Stump harvesting would cause irreparable damage to the ancient woodland.
7 Use existing equipment Many woodland owners: farmers and estate owners in particular have farm machinery including tractors and corn trailers which could be used to transport woodchips. They also often have farm buildings and corn shovels which are well suited to storage and handling of woodchips.
8 Consider the latest technology This slide set illustrates an Austrian chipper produced by KomptechNOTE:Cost approx 500,000 Euro’s but v flexible piece of kit which would seem most suitable to a chipping contractor who visited a range of sites each year;Use of ‘shoot’ or ‘elevator’ delivery of woodchips – later uses less energy and is less damaging to woodchips;Elevator installation could be added to a ‘walking floor’ woodchip delivery lorry/trailer to deliver to above ground woodchip bunkers;System includes a very capable splitter (about 40 tonnes of pressure) to split larger low quality wood to a size where it can be chipped.
9 Consider the latest technology Tractor based harvester owned by Woodwise forestry contractors based in Sussex in SE England:Finnish Valtra tractor , Finnish Keto harvesting head and Botex long reach hydraulic armNOTE:Valtra tractor chosen because drivers seat and controls can be fully swivelled to allow clear view of harvesting operation;Keto Harvesting head uses tracks rather than traditional wheels to drive the tree stem through the delimbing knives – tracks provide greater grip and flexibility to cope with twisty and slippery broadleaved trees;Botex hydraulic arm provides approx 7 m reach and allows the harvester to work broad swathe of woodland – tractor size is greater than needed to supply power to harvester BUT provides the weight to counterbalance the long reaching harvester head;In this case the tractor was second hand and was mated to the Botex arm and Keto head by Jaz P Wilson - , overall cost was approx £100,000 and system received about £42,000 grant aid from the Rural Development Programme for England administered by SEEDASystem particularly well suited to small and scattered woods in the English lowlands because of:(a) it’s manoeuvrability within a wood;(b) it’s long reach allowing it to work a wide swathe of woodland without travelling over more of it than necessary;(c) it’s ability to cope with coppice trees;(d) It can be driven between woods while larger forest scale harvesters need to be transported by costly low loader lorries (> £300 per move);(e) On board computers which measure the produce harvested in detail;(f) The harvester head usually breaks the bark of broadleaved trees helping the seasoning process.
10 ‘Turn key’ installations Hirvaskangas Heating plant just outside Jyrviskyla: Another woodheat plant in Finland built by a consortium of local woodland owners/farmers who supply woodchips from their own woods to the plant and sell heat to a growing service station come out of town shopping centre.Key message is that when a company is contracted to build a heating plant they provide a ‘turn key’ service – i.e. they ensure the system is fully operational before they ‘walk away’. Regrettably it seems common in some parts of Europe that companies will install just one part of the system – such as the boiler, and have no commitment to the overall system. This often leads to problems when the fuel bunkerage and or specification is not linked properly to the boiler or visa versa. Hence major advantage in asking for a ‘turn key’ contractorNOTE:Investors have installed the foundations for a further boiler room to allow them to add a second boiler as the heat demand grows with the growth of the site.System uses a walking floor system to deliver the chips to the auger, this allows delivery lorries to drive on.Typically Finnish installations have large augers (30cm plus) which are v robust and capable of handling lower quality woodchips which would jam smaller diameter augers.Delivery vehicles seen had walking floors in their own right and hence didn’t need to tip – good idea for systems with low height.System designed to use pellets as well as woodchips and allows blending of woodpellets with lower quality woodchips to create a ‘reasonable’ fuel.Investors are clearly looking at the long term, common to talk about payback in years but system and infrastructure will last 40 – 50 years and oil prices are not likley to decrease.
11 Engage the local community In many central European countries woodland management is embedded in the local culture with many individuals using wood themselves in the form of logs. However, they also introduce children at an early age to how wood is used for heat etc. In this case Finnish ‘toddlers’ in Toivakka are being shown the woodheat plant which provides heat for the main buildings in the centre of the village including the school.In other countries such as England the embedded culture of woodland management has been lost and many people perceive tree felling to be bad. Hence it is critical to engage your local community at an early stage and explain the many benefits of woodland management: environmental, economic and social. The ‘Wood for Energy’ poster is available free to anyone who can find a good home for it e.g. school, village hall etc. It has been designed to provide lots of information which people can pick up over time by looking at it again and again and picking up something newSee:to see an electronic copy or contact Jeanette Hawkins at the Forestry Commission for a copy on or 0044 (0)
12 Don’t burn water! Sounds obvious but water doesn’t burn very well! Wet wood will:Have a lower calorific value - effectively you are throwing away money;Produce more emissions which is bad for the environment and your pocket as it will damage your flue!Rot in the woodstore/bunkerNOTE:The simple moisture meter in the form of the domestic oven and domestic scales. In essence this offers a reasonably robust method of identifying the moisture content of woodchips – see guidance note from BEC (Biomass Energy Centre) written for WhS outlining how to assess moisture content using this method.Ideally sell and/buy woodchips and other forms of woodfuel based on calorific value NOT volume or weight. The former is based on wood density and moisture content.
13 Reminder:Supply what the customer wants – warmth i.e. sell heat and add valueKeep it localUse the whole resourceUse the equipment you’ve gotConsider the latest technology‘Turn key’ installationsEngage the local communityDon’t burn water