Municipalities cooperate on energy production
Local waste management companies joined forces to build a waste incineration plant in Mustasaari. The concrete work on the project was highly demanding.
Westenergy’s energy production plant in Mustasaari, close to Vaasa, burns the waste produced by residents of about 50 municipalities. We did the concrete work on the plant in 2012.
Petri Laitila, a frame and concrete foreman on the project, says it was the toughest project of his career. The concrete work consisted of constructing a waste bunker building, ash handling facilities, boiler house foundations, the turbine foundations, the foundations for the flue gas treatment apparatus, and auxiliary areas.
The numbers involved give a sense of the colossal scale of the project. For example, the underground slabs are as much as 1.6 metres thick.
“The whole job took about 18,000 cubic metres of concrete and over two million kilogrammes of steel for reinforcement", Laitila explains.
The walls were cast onsite, starting from 10 metres below ground level and up to a height of 45 metres above ground. The walls varied between 30 and 40 centimetres in thickness. To prevent the timber moulds from rupturing under the pressure of the wet concrete, the walls could be cast only at a rate of 50 centimetres a day. This was done also to ensure the correct drying rate for each previous layer.
“We had two concrete stations supplying concrete day and night. Although we were held back by the unusually cold winter of 2011, the project was completed on schedule,” Laitila says.
Earth construction work on the waste incineration plant began in 2009. The concrete work began in 2010, and took a bit over a year. The plant has produced electricity and district heating August 2012.
The plant uses burnable waste from the municipalities involved to generate energy. The plant is owned by the municipal waste management companies Botniarosk Oy Ab, Lakeuden Etappi Oy, Millespakka Oy, Stormossen Oy Ab, and Vestia Oy. Together these serve a total of about 50 municipalities and more than 400,000 residents. The plant produces more than one third of the district heating used in the Vaasa area.