Mull Woodchip
Group
To assist those looking at our
woodfuel ideas, I have constructed this page to view our current
position and resources.
Background
Over the last three years,
various members of the Mull Community have been looking at the
possibility of constructing a woodfuel group. The project is
expensive to develop and requires help from funding agencies to
initiate. I, for my part (Alan Parker) have applied for, and
received, funding through the A.B.D.s scheme
to construct a self catering unit. This has given me the
chance to use this funding to proceed with woodchip
for water and central heating.
Robin sedgewick
of Crannich Farm
has brought forward a plan and constructed a
combined domestic and commercial heating plant for his own
development and also to be the woodchip producer. Both parties have combined resources to drive
the woodchip group forward. Behind these individuals is a
group of about 8 others who have committed to seriously
considering woodchip if a supply chain can be firmly established.
Why timber fuel is important
The rationale for woodchip on Mull
is unquestioned because of our huge biomass supply in the forests.
The economics of taking the timber 'off island' are very 'shaky'
as it involves an expensive ferry crossing, fuel costs and large distances
on single track roads. If the cost of road repair and a
true cost of forestation was considered, the result would be a
massive loss!
However, forestry is vital to the eco
system of the world and Mull. Trees filter out and use CO2,
not to mention create habitat and stop erosion. How can we
economically use this resource to reduce Carbon emissions and manage
the forest?
Low value timber products may easily
be converted into the valuable heating product of
wood chip fuel. This requires the low tech.
processes of air drying (leaving the timber stacked
for a number of months in the open air) to a
suitable moisture content and there-after chipping
to a suitable particle size.
Carbon Neutral Woodfuel
Woodfuel is said to be 'Carbon
Neutral' as even though burning wood produces CO2, creating the
forest and managing the forest, soaks it back up again.
However, in burning wood fuel, you are only using minimal
electricity for control systems and diesel in transport.
How does it work on Mull?
(Click all images to enlarge) (mouse over them for a
description)
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- When seasoned (dried out a bit) it is
taken to the chipping and storage area
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- Chipping is done on and industrial
scale to keep costs low. The chipper is owned and
operated by a local forestry operator. Site
location Crannich Farm
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- The woodchip is blown by the chipper
into the storage and quality control shed, where it is
inspected for consistent size and moisture content
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- For efficiency, the woodchip needs to
be between 25 and 30% moisture content
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- The fuel is then delivered o the
customer either in bulk, or, by 1 cubic metre bags on a
vehicle with a crane unit.
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- Once inside the storage hopper or
silo, the chip is gathered together by 'collectors' and
fed automatically into the auger and carried into
the boiler where it is
very efficiently burned. The boiler responds
automatically to the returning water temperature.
In my case, the boiler services three properties
separated by about 50metres.
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- Delivery of hot water is by highly
insulated twin pipe tubing. This tubing is one of
the more expensive elements of the whole operation when
a delivery network is constructed.
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- Security of supply is one of the
issues that is brought up when woodfuel is discussed.
We have had meetings with both Forestry Scotland and the
contractors, Iggersons about the subject and clear
arrangements have been made to address the issue.
It has to be said that woodfuel is a major potential
outlet for timber products, and could, turn Mulls'
fragile forest economy around. Not to mention keep
down the timber miles on our roads.
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- 'Continuous improvement' is one of
our aims. The image to the right shows delivery to
my hopper in bulk using a scissor trailer drawn by a
tractor. 8 cubic metres can delivered
cheeply by this method.
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Costs
The cost of installing any of the
'alternative energy' heating options such as heat pumps, ground
absorbsion or solar panels is not cheap. Woodchip is no
exception. The burden of costs of installation is normally
cushioned by grants. In our case, we have received a 50% grant
towards the total cost. Without the grant, 'payback time' is
probably beyond most people's expectations, however, in Scotland the
signs are that support is liable to get better, and the Scottish
Executive have 'ring fenced' several million pounds towards bio
fuel. THE TIME IS RIGHT TO INVEST. calculations are that
in larger units, woodchip is about half the cost of oil. These
calculations are now two years old. I am keeping records of my
own fuel consumption and will give my costings public viewing after
one year. Even if the cost was
the same as oil I firmly believe that woodchip is worth doing on the
grounds of global warming and positive effects on the local economy.
Also, living on an island, I am a little more in control of my own
energy consumption and not dependent on expensive delivery systems.
Appropriate installation
Woodchip boilers are not suited to small buildings with limited
access to delivery vehicles. Also, the basic rule is:
The bigger the usage of hot water for heating and domestic use, the
bigger the saving. Ideal installations to get the most benefit
are: Swimming pools, facilities with public showers etc like
campsites, distilleries, large houses, particularly those that are
older and difficult to heat, housing schemes served by a common
boiler, etc etc. Bigger the better!
For smaller buildings like modern homes, wood pellet
would be more appropriate. This should only be contemplated
when a good deliver service is available. Wood pellets are
often produced from by-products of saw mills. (compressed
sawdust)
Examples
Local examples to look at are :
Mid Argyll Swimming Pool
click to link
ALIenergy owns and
operates a 200kW VITO woodchip boiler at Mid Sargyll Swimming Pool,
Lochgilphead. Visits can be arranged
ALIenergy
can also arrange visits to the 50 home district heating scheme at
Whitegates, Lochgilphead. ALIenergy also has expertise in woodfuel
supply chain development
New
schemes at Aqualibrium in Campbeltown and Glenshellach, Oban will
see biomass plant assisted by ALIenergy exceed two megawatts of
installed capacity
Help.
In my own county, Argyll, expert and
independent help can be gained from :Alienergy
A fact sheet in PDF about small scale biomass can be
gained by
clicking here
Other useful links:
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