I-001-FI-019-EN
mml
● ● ● Particularity : small-scale private district heating network that sells the heat it produces.
The wood energy Trail
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Saint George : a small wood chip-fired district heating Valorisation of forestry by-products
Information on the community
In 1993, Henri Berseth, a forester, decided to put the wood unsuitable for commerce resulting from pruning, coppicing and felling in local
• Altitude : 945 m, • Population : 730 inhabitants, • Forest : c. 760 hectares.
Photo AJENA
The storage hangar
Exterior view of the boiler house
Programme of the Jura Department
community-owned or private woodlands to good use. Before it can be burned, firewood takes a lot of handling, and a minimum of two years to dry out. For this reason, if forestry by-products can be ground on site, the burden of handling the wood is reduced and the drying time is reduced to only two to four months. This means the work carried out can be transformed into profits more efficiently. In keeping with this activity, Mr. Berseth decided to install a wood chip-fired boiler in his home and to commercialise the heat thus produced. A small-scale district heating network heats five buildings equipped with substations : the school, two private homes, the Berseth family home and the company premises. Other local people are taking a great interest in the undertaking and are waiting to be joined to the network, which is technically possible because the boiler was deliberately built oversized in order to accommodate further connections.
Mr. Berseth’s company provides the fuel to its customers. A hangar with a capacity of 500 m3 situated near the boiler room provides storage for fuel throughout the period during which heating is needed. The fuel is a mixture of broadleaf and resinous wood with a moisture content of between 30 and 40 % of the gross weight. After drying out for at least two months in the hangar, the fuel is delivered by means of a hopper of 6 m 3. This is the only solution possible given the situation of the two silo doors, underneath the roof, which prevent delivery by a tipper lorry (see photo below left, where the silo is visible to the left of the house). The wood chips are unloaded into a 50 m3 silo equipped with hydraulic scrapers to transfer the fuel to the boiler. In addition, to prevent the hydraulic rams from using too much electricity, a small intermediary silo of 1 m3 was installed. This means the scrapers only function for half an hour per day. The annual consumption in wood chips is estimated at 500 – 600 m 3 per year. The company also sells nearly 400 m3 of wood chips per year to other farmers with similar boilers. In this case, the fuel is delivered in a lorry with a capacity of 35 m3.
A self-operating boiler plant The HATA boiler has an output of 130 kW and its combustion system is an underfeeder screw. The system burns wood chips with a moisture content of up to 40 % of the gross weight. The boiler is equipped with an automatic ash-clearing system, which stores the ashes in a small container, which must be emptied once a week. The flues carrying smoke from the exchanger
© ITEBE- july 1999
Photo AJENA
Fuel supply