During the summer of 2014 Linka installed a large, mobile heating plant for the Swedish municipality Aneby. The new plant has already resulted in significant savings on heating prices.

Background

Aneby Municipality is located in the southern part of Sweden, 45 km from Jönköping. Aneby AMAQ (Miljø & Vatten AB) delivers heating for around 250 houses and a large industrial area. Before the new plant was installed, Aneby was Sweden’s most expensive area regarding heat prices. In only two years Aneby has advanced 85 spots on this list.

Heating was previously delivered from a plant owned by a private company. Due to the agreement with the owner, AMAQ faced financial loss which affected the high heating costs. After a visit at Mullsjö District Heating where Linka had previously installed a biomass plant, and with a plan to become self-sufficient, Aneby chose to invest in a new mobile heating plant.

Linka was chosen as the supplier due to our experience from delivering similar plants. We were also able to offer a reliable, flexible system for a competitive price.

Considerations

The contract between Aneby AMAQ and Linka was finalised in February 2014. Due to the expiration of their current supply agreement the new system needed to be operational in June, only six months later. A challenge, that Linka could meet.

The new plant was replacing a 6.3 MW boiler from the early 1980’s, and another 2.2 MW boiler along with an oil backup. An important factor for Aneby was flexibility in the construction of the plant. Linka was able to meet this demand.

By installing four 3,000 kW boilers instead of a large 12,000 KW, the supply is adjustable for the area’s changing weather. The installation of several smaller boilers ensures that the output can be regulated from only 300 kW up to 12,000 kW, when all boilers are operating on full loads.

While one of the boilers can supply the area with heat during warm months, it takes three boilers to keep the residents warm during the winter. This means that the fourth boiler is used as a backup for extraordinary cold weather.

The solution

Linka was a turnkey contractor on the mobile system which consists of four plant containers, two with wood pellet boilers and two with wood chips boilers. A service container with a small office, pumps and pressure system was also installed.

The wood chips boilers are fed from a large silo. The chips are transported from a scraper unit through a distribution bin which distributes the fuel between both boilers. The pellets are stored in two large silos which feed the other boilers. The control system on the fully automated plant ensures a constant, optimal fuel feed to achieve the highest efficiency.

Ash from the boilers is automatically transported from the main containers to ash containers placed at the back. The plant only needs minimal supervision.

The combination of wood chips and pellets as fuel ensures a high flexibility. Aneby can change the primary fuel depending on pricing and supply, and achieve as low costs as possible along with a high supply security.

Specifications

Customer: Aneby AMAQ (SE)
Location: Aneby, Sweden
Fuel type: Wood chips and pellets
Plant size: 12,000 kW (4 x 3,000 kW)
Plant type: Mobile plant
Energy type: District heating
Year: 2014