The biogas plant of Pielisen Bio Oy, completed in Lieksa, is a concrete example of the green transition in regional industry. However, the journey to a successful outcome was not entirely smooth, as the project had previously been halted by unexpected challenges: the bankruptcy of the previous contractor stopped construction, financing had to be rearranged, and changes occurred among the gas off-takers. Persistent effort and close cooperation were ultimately rewarded when the plant was commissioned in August 2025. The significance of the new facility for local industry and agriculture is already considerable.
A significant step toward a true circular economy
Lieksa took a major step toward sustainable energy production when Pielisen Bio Oy’s Wetferm biogas plant was completed in August 2025. The project was implemented during the period 11/2024–08/2025. The project had an exceptionally challenging starting point: the bankruptcy of the previous contractor in autumn 2023 had left the site unfinished, and reorganizing the financing proved difficult.
Doranova Oy’s CEO, Antti Myllärinen, describes the project as follows:
“The Pielisen Bio project could be described as a journey from adversity to success. Due to the bankruptcy of the previous contractor, the project had been left unfinished in autumn 2023. Doranova began reviving the project together with Pielisen Bio and the main financier, One1 Oy, in May 2025.”
The financing challenges were further compounded when one of the major gas users announced in summer 2024 that it would discontinue its production operations in Lieksa.
“Despite these setbacks, the number of gas off-takers and the possibility to distribute gas locally via a pipeline increased confidence in the project’s profitability. After intensive efforts, construction work was launched just before freezing conditions began, and progress thereafter was rapid.”
Biogas for local industry
The completed biogas plant processes liquid manure, grass biomass, and by-products from the local food industry, totaling approximately 20,000 tonnes per year. The digestion process is carried out in two Wetferm reactors (4,250 m³ and 2,500 m³), with the German company Sauter Biogas GmbH acting as the technology partner. Thanks to post-hygienisation, the resulting fertilizer fractions meet safety requirements and are suitable for use in local agriculture.
The plant produces approximately 8–10 GWh of biogas annually. The gas is dried and purified using activated carbon filtration before being fed into a nearly three-kilometer-long low-pressure gas network built as part of the project. Customers connected to the network include food industry operators, a laundry, and other industrial actors in Lieksa.
Part of the gas is utilized for heat production within the biogas process itself as well as for heating an industrial property owned by the City of Lieksa. These heating plants are operated by Pielisen Bio Oy. Doranova supplied two heating plants to the site: one with a capacity of 500 kW and another of 1,500 kW.
Jarmo Yletyinen, Project Manager and Board Member of Pielisen Bio Oy, describes the project as follows:
“The biogas project has received broad support in Lieksa among the local population and businesses. The project also strongly supports the city’s climate strategy by reducing greenhouse gas emissions and replacing the use of fossil fuels with renewable local energy. Official commercial gas sales received final confirmation on November 25, when a classification body accredited by Tukes officially approved the commissioning of the gas pipeline.”
From a challenging start to a successful outcome
The biogas plant was formally handed over to the client in August 2025. Following the handover, the biological process ramp-up has continued, and gas customers’ consumption points have been converted to operate on biogas. According to Myllärinen, the completion of the plant quickly generated positive signals:
“During the winter of 2025, additional gas users came on board, and at present the plant is assessing additional feedstocks, as the original gas demand projections are already being exceeded,” Myllärinen says with a smile.
The quality of the work and the successful outcome of the project, despite its challenging starting conditions, received well-deserved praise:
“Our thanks to the Doranova team for the good and professional cooperation that brought the project through challenges to a successful finish. This is a great foundation to build on,” Yletyinen commends.
Watch the presentation video of this plant that puts true circular economy into practice below.
