The Regional State Administrative Agency for Southern Finland has granted an environmental permit for the expansion of operations at Mäntsälän Biovoima Oy’s biogas plant. The expansion will double the company’s biogas upgrading capacity and improve its ability to receive sludge.
The expansion will increase the plant’s capacity to receive and process biodegradable waste from 20,000 to 43,000 tonnes a year. This will raise biogas production to around 33 gigawatt-hours, covering the annual heat and energy needs of thousands of households. Following the expansion, the plant will also produce around 65,000 tonnes of recycled fertiliser a year.
The project includes the construction of a new biogas reactor, associated sanitisation and hydrolysis processes, and a fertiliser storage facility. The company will also increase its recycled fertiliser storage capacity and install a second odour scrubber alongside the existing one. The expansion will not increase the plant’s environmental impact.
“The decision confirms that this important investment can move forward. We will be able to produce more domestic renewable energy without increasing the environmental burden,” Auris Energy’s Chief Growth Officer Ville Karttunen says.
Mäntsälän Biovoima Oy is majority-owned by Auris Energy. The minority owners are Nivos Oy and Watrec Oy.
The expansion project has received funding from the Ministry of the Environment.
Read the Regional State Administrative Agency’s full press release: Environmental permit granted for changes to operations at Mäntsälän Biovoima Oy’s biogas plant, press release 27 August 2025 – Regional State Administrative Agency