Wood Fuel Supply Chain Options
Sources of wood fuel include short round wood logs, wood chips and wood pellets. To decide which wood fuel would be best to utilise in Barony College a quick price comparison of fuels was made.
Below is a comparison of prices of conventional fuels and wood chips and pellets. Short round wood was not included in this comparison, since it cannot be utilised in automated systems, but they are cheaper than wood chips to buy.
Graph 1: Comparative Heating Cost of Fuel 4
This graph shows that wood chips and wood pellets are able to economically compete with conventional fuel. Although wood pellets are economical when compared to conventional fuel, in a large scale biomass system, such as the one to be used in Barony College (350kWh), wood chips work out much cheaper to use. In addition there are currently no suppliers of wood pellets operating in Scotland on the scale required by Barony College. Although Balcas Ltd. (a Northern Irish Supplier) is proposing an Invergordon Based depot, this will introduce prohibitive environmental and financial transport costs.
When considering a fuel supply for Barony College, supply in Scotland and in particular, Dumfries and Galloway was considered. Below is a table of woodland coverage in Scotland, measured in thousands of hectares.
Table 1: Woodland Coverage in Scotland 2.
Around 17% 3 of Scotland’s land is covered in forestry and from the table it can be seen that about 35% of this forestry cover is owned by the Forestry Commission and around 65% is privately owned. Presently, there is a lot of work being carried out by the Forestry Commission and the Scottish Executive to encourage the growth of biomass in Scotland, which looks set to become a very popular fuel source for the production of heat and power. Therefore, these figures are encouraging when considering sourcing wood fuel in Scotland.
Currently there is limited supply of wood fuel in the Dumfries and Galloway area. However, this looks set to change within the next few years with one of the driving factors behind biomass, in the Dumfries and Galloway area, being E-ON, an energy company that generates and distributes electricity. E-ON are building a 44MWe power station dedicated to biomass (wood fuel in particular) in Lockerbie, they therefore need a supply chain up and running by the time the plant hopes to enter commercial operation in October 2007.
Although E-ON will have its own dedicated supply chain there should not be a problem with any excess fuel generated being sold to the public. This initial supply chain for E-ON will stimulate the market in the Dumfries and Galloway area and wood fuel will become more widely accepted, this in turn will also enable the skills base to grow and stimulate employment in the industry.
This has already started to happen in the area and there have been applications for grants offered by the Scottish Biomass Support Scheme (SBSS), by potential suppliers (who can not be named at present, due to confidentiality acts). Therefore, there should be a supply chain developing in Dumfries and Galloway shortly (within the next two years1).
There are three supply options available to Barony College for obtaining
wood fuel. These are:
This option would require Barony College to purchase their wood fuel from local suppliers, such as forestry owners and contractors, saw mills, fuel merchants or fuel supply co-operatives.
The Forestry Commission is a good place for Barony College to source their wood fuel. However, there are also opportunities for Barony College to obtain this from private forestry owners, of which they have links with presently, and also from specific wood chip suppliers. The Logpile Website and Renewable Energy Association give a comprehensive list of wood fuel suppliers in all areas of the UK and Table 2 shows those located in the Dumfries and Galloway area.
Table 2: List of Wood Fuel Suppliers near Barony College.
The Dumfries and Galloway area is also an ideal place to promote wood fuel as there are many sawmills in the area, which could be potential suppliers of wood chips. Table 3 shows sawmills and their contact details.
Table 3: List and map of sawmills in Dumfries and Galloway area.
The Scottish Forest Industries Cluster also plays a large role in Dumfries and Galloway supporting Scottish Biomass and the Confederation of Forest Industries (UK), CONFOR, are also strong advocates for wood biomass in the area, holding many workshops and providing information for potential suppliers and end users.
Our calculations show that at 30% moisture content 244 tonnes of woodchips would need to be sourced to satisfy the demand of a sixth month heating season. This calculates to 1.34 tonnes per day from October to March. Taking the assumption that a 7.5 tonne lorry, with 30m3 storage volume, is utilised to make deliveries this equates to one delivery every ten days. Therefore with a safety margin of 10 days fuel set aside for supply disruption 60m3 of fuel storage is required.
The table below highlights potential annual costs of this supply option:-
Scenario 1: Woodchips Purchased:
The basis for cost and quantity calculations is shown in the financial analysis section.
Another option, popular in Europe but still growing in the UK, would
be to obtain wood fuel from an Energy Service Company. In this case the
customer is billed, at an agreed price, for heat supplied rather than
fuel supplied. The Energy Service Company usually operates and maintains
the boiler and can either own the boiler or lease it from another company.
It is therefore the ESCo’s responsibility for ensuring heat is supplied
on demand and it is the ESCo is able to choose the fuel source it feels
most suitable for the boiler. The advantage of buying heat and other services
from an ESCo is the little input that the final user needs to have with
the installed biomass system, thus negating any worry about maintenance
and fuel supply that a biomass boiler may pose. The time period of a contract
can be seen as a disadvantage when buying services through an ESCo as
the tarrif may not stay competitive. Also there is a restricted choice
of ESCo’s currently in Scotland.
Table 4: List of Energy Service Companies in the UK.
The third option available to Barony College would be to buy in green small round wood from local forestry sources. This small round wood can then be stored on the premises to air dry, and would give Barony College the chance to teach students the processes involved in producing wood chips, such as drying techniques and chipping techniques, which is possible as the college does own its own chipping machine, as well as contribute to a definitive guide of drying methods within the UK.
This option does have the disadvantage of needing two fuel stores, one for the round wood and one for the chips once ready for combustion. In addition the drying period can range from a year to a year and a half which alongside the time required to gain the necessary fuel processing skills could mean this is more of a long term supply option. However, it does offer a cheaper alternative to buying in chips as well as having educational advantages, and can be a possibility in the future after the initial system has been installed.
It has already been stated that at 30% moisture content 244 tonnes of woodchips will be required. For this supply option this equates to purchasing 325 green tonnes. These can be obtained at approximately £18.50/tonne (including transport, Forestry Commission).
Scenario 3: Green Roundwood:
The basis for these cost calculations are found in the financial analysis section..
Both wood fuel and anaerobic digestion are potential biomass fuel sources for Barony Collage. At this stage woodchips seem the most promising fuel source. The strong support for wood as a biomass fuel type in the Dumfries and Galloway area makes the supply look promising for the future, thus reducing the risks of fuel shortages.
Forestry Facts and Figures 2006. A Summery of Statistics about Woodland and Forestry. Economics and Statistics Forestry Commission. Crown 2006, ISBN 0 85538 706 8
Forestry Commission Scotland and Scottish Executive 2007, RR Donnelley. Biomass Action Plan for Scotland. Crown 2007.ISBN 978 0 7559 6506 9.
Forestry facts and figures for the UK can be found at the Forestry Commission website.