Biomass District Heating

After an installation period which started in 1998 on the 27 March 1999 the first of now 7 buildings was switched over from LPG gas to the first wood chip (biomass) district heating system on the island of Ireland and one of the first in the whole of the UK.

Having a hot bath that night felt very different. Somehow knowing that your heat source is a renewable one, running on waste wood material instead of fossil fuel, is a great satisfaction.

How did it come about?

For years we have improved our estate, fields, hedges and so forth planting thousands of trees and thinning existing wood lands as well as coppicing overgrown hedges creating piles of waste wood material.

Having experienced wood-chip-heating systems in various locations across Europe it was a wish for a long time to use at least our own waste wood as an energy crop.

With the planning of a multi-purpose farm building, it became clear that this was the time to incorporate such a system.

Grant assistance through the DED's energy demonstration scheme secured the project for us.

Our choice of wood biomass boiler

After visiting some of the main boiler manufacturers on the continent in 1997-1998 to study best value for money techologies

A Fröling Lambdamat Industrial 320 kW boiler was chosen.

District heating pipe

Pre-insulated steel pipework from Logstor ror in Denmark was used for the district heating supply to the houses.

We carried out the installation ourselves after disappointing service by a consultant.

Wood chipper

The UK and Irish market has an abundant choice of wood - chippers and shredders unfortunately the vast majority has not been designed for the renewables heating sector, causing major problems when used for wood-chip boiler fuel often resulting in expensive screening of the chip.

These chippers are designed to reduce wood for mulching or composting.

There are few manufacturers in Europe who produce chippers specially designed for the biomass sector which produce high quality wood-chip.

Drummed and screened chippers are generally the best design to produce good chip.

To test a chipper for its suitability! Birch and willow twigs are the most difficult to chip often resulting in long twigs (in excess of 100mm) getting through the chipper.

Round clean logs are easiest to achieve good chip quality also in some not so good chippers.

At Clanabogan we use a Starchl chipper since 1998

The Starchl chipper produces excellent chip with all wood materials and has very low maintenance requirements.

The right chipper is highly important for smooth operation of auger fed G30-50 wood chip boilers.

During its years of operation and having expanded the system to the maximum of the boiler's capacity it has proven its reliability and helped reduce heating costs substantially.

The co-operation of the boiler manufacturer Fröling Austria who were always helpful and swift in sorting out some of the minor problems we encountered, leads us to highly recommend them.

Some Data

During the first 1.5 years of operation all wood-chip was produced by us using waste material in our locality.

With the expansion of the system in year 2 (2000-2001) it became necessary to purchase a proportion of the material.

A large sawmill in Enniskillen produces between 100-300 tons per week of wood-chip or sawdust.
We have been purchasing material at the cost of £ 16 / ton delivered, for the first years adding up to approximate running costs of £ 4,000-£5,000 per annum.
Possible savings against oil and gas are between £ 15,000-£25,000 per annum depending on prices.

Wood biomass heating possibilities for camphill communities

Wood biomass is a sustainable carbon neutral material which is readily available in most parts of the British Isles.

For heat energy purposes the lowest value wood finds a good use by replacing oil or gas.

In the British Isles we have a smaller percentage of forested area compared to many other European countries but the timber is faster growing therefore often of a lower quality leaving more low grade residues which are very suitable for energy purposes.

By using these by products or lower value wood, forest owners, sawmills etc. can increase their profitability, this encourages woodland management and forest planting and can lead to sustainable wood-land management.

The British Government is in the process of finalising a sustainable zero carbon heat incentive which would mean ongoing financial support per kw of heat produced in wood-chip boilers from April 2011 (NI to be confirmed).

Most Camphill Communities have estates and farms with a substantial potential for wood biomass production on site. Farm and woodland management could be geared to produce quantities of sustainable wood biomass on site simply by managing what is there and by introducing more coppice undergrowth.

Existing hedgerows can be managed in a way that they can produce wood biomass whilst at the same time increasing bio diversity and rejuvenating their growth.

Proper management of woods, forests, trees hedgerows, shrubs coppice etc, is very important on bio-dynamic holdings since it helps to stimulate and regulate the biodiversity within an Agricultural Organism.

"In districts which are pre-destined to be wooded, the regulation of woods and forests is an essential part of agriculture, and should indeed be thought of from the spiritual side. It is of a far-reaching significance."

Rudolf Steiner.

(Agricultural Course lecture 7 / 15^th June 1924)

Although most communities will initially not be able to grow all their wood biomass themselves and large quantities would have to be purchased locally anything that is utilised on site would be a financial saving and environmental benefit.

Biomass Boiler

A good wood burning biomass boiler is a controlled wood fire, where a computer controls and optimises the combustion process through sensors in the flue gas (Lambda sensor) underpressure in the combustion chamber and temperature sensors at different stages throughout the boiler. Combustion is optimised to such a high degree through injecting air at different levels (primary, secondary and tertary combustion)  in to the combustion process that most of the gases (volitiles) are burned, the energy stored in wood is released and transferred in to usable hot water.

The feeding system in the case of wood-chip or pellet boilers is fully automated the labour intensive disadvantages of solid fuel firing have been largely overcome.

Where making a fire outside is regarded as damaging to the environment because 70-80% of the gases stored in wood are released in to the atmosphere un burned a wood biomass boiler utilises 90-99% of these gases turning 1 ton of wood in to 3000-5000 kw of energy which is the equivalent of 300-500 litres of heating oil and leaving a small amount of ash with a high pot ash content.

For further information contact
martin@camphillclanabogan.com