Wood for energy

Overview

BioRegional and wood for energy

In Britain, with increasing concern about climate change, wood is now an increasingly attractive energy source along with other forms of biomass. Modern biomass boilers are efficient and clean and wood energy is renewable, as once trees or other biomass such as elephant grass (miscanthus) are harvested they are replanted and grow again, reabsorbing the CO2 emitted when the wood is used.

BioRegional has promoted wood for energy since 2001. Our aims are to:
• develop a commercially viable model for woodchip fuel supply at local scale;
• promote wood as a fuel and develop a supply chain for wood fuel across London and elsewhere; and
• work with others in the emerging industry to make using woodchip “as easy as paying the gas bill”.

We have been developing our work through:

TreeStations – collection areas for woody waste that would normally go to land fill. The waste is turned into woodchip for energy or logs for heating.

BioRegional Forestry – an independent company providing a sustainable forestry service in south East England, including logs for domestic heating.

Background

Wood for energy in the UK

Using wood for fuel will help bring under-managed woods back into management. This in turn will open up the woodland canopy allowing more light to reach the ground. Conditions will be greatly improved for wild plants, butterflies and animals which have been declining in recent years such as the dormouse and the nightingale.

In the UK there is a lot of timber potentially available for fuel. For example, in south-east England the National Inventory of Woodlands and Trees completed in 2000, indicated that over 1 million tonnes of fuel wood could be harvested each year. The Forestry Commission has a target of an additional 2 million tones of wood fuel produced from Britain’s woodlands annually.

Other sources of wood fuel
Woodlands are not the only source of wood fuel. In urban areas the trees on the streets and in parks and gardens all produce timber. A 2005 survey by BioRegional working with the London Tree Officers’ Association estimated that 127,000m3 of tree waste is produced each year. Much of this poses a disposal problem for tree surgeons.

Untreated reclaimed timber from demolition sites and clean waste pallets can also be used as fuel. Waste from timber using industries is increasingly used for pellet production. Finally, trees such as willow and poplar can be planted as short rotation coppice and cut every 2 or 3 years for fuel. An assessment was made by BioRegional of the wood fuel potentially available in London in 2005, identifying a minimum of 500,000 tonnes a year after allowing for existing uses. The report, Biomass fuel assessment for the Z-squared combined heat and power plant, is available for download from our publications page.

Wood and other biomass has an advantage over other renewables such as wind and wave since it can be easily stored until it is needed. This flexibility in use comes at a cost as it has to be harvested, processed and physically transported from where it grows to where it is used, slightly offsetting the CO2 emission reduction from using wood fuel.

Wood is now recognised as good value, at least as cost effective as other renewables. Following price rises for fossil fuels in 2005 woodchip is cheaper than natural gas. Its potential was recognised by the government when they set up the Biomass Task Force. Their report identified potential for wood fuels to save 3.6 million tonnes of carbon emissions nationally from existing resources. Planting biomass is an attractive way for farmers to diversify their businesses. The government’s response to the task force report, published in April 2006, supported its conclusions and contained commitments to foster the development of wood and other biomass as modern energy sources.

Types of wood fuel
There are 3 main types of wood fuel used in modern systems in the UK, Europe and elsewhere: logs, woodchip and wood pellets.

Logs
The traditional form of wood fuel which can be easily stored, air dried and burnt in a wide range of appliances from open fires to modern automated boilers.
The advantages of logs are:
• they are readily available, although there are no guarantees of quality so the buyer has to make sure they are suitable for the proposed use.
• bought in bulk, they are the cheapest form of wood fuel;
• they are almost always locally produced, so buying logs benefits local woodlands and the local economy.
The disadvantages of using logs are:
• there is no agreed quality standard, so logs may be the wrong size or too wet
• using logs requires more involvement than other forms of wood fuel, stoves have to be loaded and cleaned, and even highly efficient modern boilers have to be loaded on a daily basis.

Woodchip
Woodchip is widely use in other European countries as a fuel for heating and in combined heat and power systems, particularly in countries with a strong forestry tradition such as Scandinavia and Austria. Woodchip boilers are available for all scales of operation though CHP plants are normally larger serving a town via a district heating scheme.
The advantages of woodchip are:
• it is cheap, often as cheap as logs and now (June 2006) cheaper than mains gas;
• it is a standardised product with Europe wide quality standards in place;
• fully automated, highly efficient boiler systems are available;
• it can be made from a wide range of raw materials, often sourced locally.
Its drawbacks are:
• fuel quality is often variable, since suppliers are still inexperienced;
• it can be difficult to find supplies without assistance;
• it is a bulky fuel, leading to storage problems in some sites, particularly at the domestic scale.

Wood Pellets
Wood pellets are a highly compressed standardised product made from sawdust, normally without other additives.
Their advantages are:
• they are a consistent fuel with low moisture content which can be easily handled in automated systems;
• a wide range of appliances are available to burn pellets, from single room stoves to large district heating systems. Fully automated boilers are the norm;
• bulk density is around 4 times that of woodchip, requiring less storage room making them more convenient at a domestic scale. In other countries bags of pellets are commonly sold on filling station forecourts.
Their disadvantages are:
• supplies of locally made wood pellets are hard to find in the UK, most are imported at present;
• they take energy to make and are often transported long distances, reducing the environmental benefits of using a wood fuel;
• they are expensive, around twice the price of woodchip.

Developing local woodchip supplies
Woodchip fuel is increasingly seen as an important element in reducing our CO2 emissions. Wood provides the greatest amount of renewable energy across Europe, though this is over looked as most is used in small heating projects. The UK has very low levels of wood fuel use by European standards but is beginning to increase this as the economic and environmental benefits become clearer. There are clear commitments to support the sector from government and cost savings for users.

London is in the vanguard of biomass uptake thanks to policy initiatives by the GLA. There is a city wide requirement for larger new developments to include 10% on-site renewable energy generation, with some boroughs having more demanding policies. Heating with wood is often the most cost effective way of achieving this and the use of woodchip and pellets is set to increase. Wood waste from tree management and commercial sources is generated all over London creating a substantial local fuel source.

TreeStations

TreeStations - turning wood waste into renewable energy

Many woodlands are poorly managed, in large part due to the falling price for timber which makes it uneconomic to thin woodlands. Small logs coming from young woodlands are the least valuable of all and are particularly hard to sell. Providing a market for this large amount of low value produce helps woodland owners and managers, people working and living in the countryside, and benefits wildlife conservation and biodiversity. There are many trees in urban areas too, along roads, in parks and gardens and in woodlands within towns.

TreeStations can help make best use of the timber that results from managing trees and woodlands in rural and urban areas.

What is a TreeStation?
A TreeStation is a site where local woodland and tree managers and owners can bring their woody waste to, rather than sending it to landfill. The station will then convert the wood into useful projects. TreeStations will have environmental, social and economic benefits, in particular they are:
• based around commercially viable use of local timber
• are a focal point, acting as a hub for users of forest products
• centres of local excellence in sustainable forest management
• committed to maximising environmental benefits from woodland, for example by concentrating their attention on restoring management to ancient and semi-natural woods
• designed for a regional or local scale of operation to minimise the environmental impact of transporting timber and wood products, and to increase benefits to people working and living locally.

TreeStations offer a holistic approach encompassing both management of trees and woodlands and the use made of their products. Each TreeStation has one or two core activities providing stable outlets for woodland products. Other wood-using activities can grow around this, making best use of the available wood resources, generating employment and adding as much value as possible.

Rural TreeStations
TreeStations are not just for urban areas. Similar benefits can be had by aggregating timber from small woodlands in rural areas. South East England is especially suitable for a TreeStation with its wealth of small woodlands with a multiplicity of owners. Marketing produce from individual small woods is hard but together they can are a significant resource.

For example, it is difficult to plan and carry out woodland maintenance work such as thinning of young tree crops, and it is hard to sell small loads of low value timber. Even the Forestry Commission who give grants for woodland management find it difficult having contact with owners of just 30% of privately owned woodland, implying that many are receiving little if any attention. A TreeStation will stimulate increased management of neglected woodland by developing a market for produce from them and providing a base for wood-using businesses. The result is a more attractive landscape with higher environmental and biodiversity values.

BioRegional plan to establish at least one rural TreeStation. This will show how bringing together woodland management, processing and the use of woodland products on a local and regional scale can create a viable business where there was none before.

Each TreeStation will be based around a central activity such as a sawmill, charcoal production, or woodchip for renewable energy. By drawing in material from many, mainly small woods the TreeStations will be able to select material suitable for sawn timber or other high value uses. It is envisaged that a cluster of wood-using businesses and providers of services such as woodland planning will develop around the TreeStation, much as it has at Croydon.

Croydon

Croydon - the UK's first TreeStation

So far BioRegional has set up one TreeStation as part of a partnership with the London Borough of Croydon and City Suburban Tree Surgeons. Since 1996 we have worked with Croydon Council to:
• improve the management of the borough’s trees and woodlands
• reduce the amount of wood entering the waste stream
• establish a fully operational TreeStation in Croydon.

City Suburban joined the TreeStation project in 2004 as we moved towards woodchip fuel production.

A TreeStation is especially valuable where many owners each have responsibility for a large number of small woods and trees. TreeStations act as a catalyst for sustainable forest management through the development of new wood-using industries which match the available woodland products.

Our work at the Croydon TreeStation is setting an example by:
•improving the value of the environment for local people by bringing woodland into management
• demonstrating good management of trees in Croydon through certification under the Forest Stewardship Council (FSC) scheme
• involving local people in woodland management and ecological monitoring
• diverting up to 10,000 tonnes a year of waste wood from landfill
• developing new markets for timber in products such as charcoal, woodchip for fuel and sawn timber craftsmen and furniture makers.

Development of woodland management at the Croydon TreeStation.
Despite its urban setting Croydon has several woodland areas which are highly valued as a place for quiet enjoyment by local people. Until the partnership between BioRegional and Croydon Council the area’s woodlands only had limited practical management. Many areas that previously managed as coppice were overgrown and the variety of light and shade, young growth and older trees was lost.

Active management has been restarted in four woods. Rides have been restored, coppicing reintroduced and unwanted invasive species, such as sycamore, are being progressively removed. Work started by BioRegional with project funding has resulted in a new forestry management business employing 3 people. The cost of the work has been surprisingly modest, as full advantage has been taken of grants available from the Forestry Commission, some timber has been sold for pulpwood or firewood, or made into charcoal. Other coppice products have been marketed locally.

The result has been a rapid return of spring flowers such as primroses and bluebells in the coppiced woodland and the return of other, less obvious plants and animals. The biodiversity benefits of bringing woodlands back into management are clear and the young shoots of the regenerating coppice have increased variety and interest for people walking in the woods.

Trees don’t just grow in woodlands. In an urban setting like Croydon trees along streets and in parks and gardens are vitally important. The council was the first local authority worldwide to gain FSC certification for the management of all the woodlands and trees for which it is responsible. This was independent endorsement of the high standard of systematic management through regular inspection and maintenance of Croydon’s ‘urban forest’.

The TreeStation in Croydon has been established primarily to use the wood produced by arboriculture within the borough. Wood is diverted away from the waste stream and used to make a variety of products. Charcoal was made for 4 years up until 2000 and the small proportion of high quality logs were sawn for timber using the TreeStation’s mobile sawmill. When BedZED was built charcoal making ceased and we developed the woodchip production unit. City Suburban Tree Surgeons have been running the site as a commercial venture since March 2006. Arboricultural waste arising from management of the Council’s own trees and from tree surgeons working elsewhere are accepted at the site.

The first market for woodchip was for 1000t/yr at BedZED for the combined heat and power plant (CHP). This coincided with growth in interest in woodchip as a heating fuel so we have increased the capacity at the Croydon TreeStation to 8000t/yr. Availability of fuel nearby has led to strong local interest in woodchip heating so despite the failure of the BedZED CHP so far future prospects for the TreeStation are good. Five local building developments have opted for biomass now that they are confident of a secure supply - a residential development, two care homes, a school and a district heating scheme. Interest is also growing among other London authorities. Discussions have started with Haringey, Hounslow and Sutton about setting up similar TreeStations.

Now the project faces the challenge of finding an effective and cheap technique for drying the woodchip because, although the Slough Heat and Power station can handle undried waste, smaller boilers need the woodchip to be drier. So BioRegional and City Suburban are exploring the use of fabric covers which would keep rain out of the chip pile while still letting water vapour produced by the heat generated in the chip pile escape.

Certification

Why forestry certification is important

Forest and woodland certification provide a guarantee to buyers of forest products of good management of the forest where the tree was grown. This is done by an independent inspection and assessment of the forest and the way it is managed against a clearly defined set of standards. These standards, which should be applicable to all forests and woodland in an area, cover environmental, social, and economic aspects of management.

Forest certification is relatively new. It was developed in the 1990s to address concern over destruction of forests in the tropics and elsewhere, such as northern Russia, where logging was seen as an important cause of forest loss. From small beginnings development has been rapid with tens of millions of hectares of forests now certified and increasing support from retailers in countries such as the UK.

By far the largest certification system in the UK is the scheme run by the Forest Stewardship Council (FSC). Over 1 million hectares in the UK, including all Forestry Commission woodlands are certified under the FSC scheme.

The FSC was founded by a group of environmental organisations, including WWF and Greenpeace in 1993 but is structured to achieve a consensus about how certification develops by giving similar weight to the views of environmental organisations, forestry professionals and industry, and forest dwelling peoples and traditional forest owners. Governments are excluded from FSC membership.

The FSC has a set of 10 principals and criteria (P&C)which are the agreed basis for forest management world wide. National or regional working groups which include representatives from all with interests in forests and woodlands interpret these P&C for local conditions. In this country the UK Woodland Assurance Standard is the basis for FSC certification. For more information about the FSC system see the FSC UK website and FSC International website.

An alternative system operating in UK is the Pan European Forest Certification (PEFC). Just 9,000 hectares were certified under the PEFC system in UK in January 2004. While the PEFC system has many superficial similarities with FSC it is not generally regarded as equivalent to the FSC system.

Compared to FSC PEFC:
• is not a world wide system, only applying in Europe; and
• does not require independent third party inspection of each forest certified under its regional certificates
• does not have a set of performance standards with clear minimum environmental and social thresholds. Instead each participating country sets its own standards which are approved by the PEFC general assembly.

BioRegional has supported FSC certification since our foundation as the only credible global forest certification system. All the charcoal, firewood and kindling sold through the BioRegional Charcoal Company is FSC certified. When BedZED was built specifying FSC timber was important in minimising its environmental impact. The FSC system has a good balance between different interest groups and maximises environment protection. It has proven rigorous, practical and cost effective to use.
 
Both FSC and PEFC support their forest management certificates with “chain of custody” certification which allows certified timber to be traced from the forest all the way through production processes to the final product on sale. . Many major retailers have supported the FSC by committing themselves to sell only FSC certified wood products. Over 30% of people in a recent survey recognised the FSC label. Next time you go shopping look for the FSC label on wood products. When you have a barbeque in the summer, buy FSC certified charcoal.