Finland | Joensuu advances towards non-burning district heat

The participants of the regional stakeholder group of Regional Council of North Karelia met on May 22 to discuss the latest achievements of the EXPRESS project and the energy sector in North Karelia. In the meeting, the results of the latest studies, current projects, and the lessons learned from the EXPRESS project's study visit to Paris were presented.

Regional Council of North Karelia commissioned a techno-economic study to evaluate the wind potential of 30 areas by examining wind conditions, road coverage, proximity to substations and power grids, and soil conditions. Preliminary findings suggest that up to 1,184 wind turbines could be theoretically installed in these areas, which is notable given the absence of wind farms in North Karelia. Detailed site cards will be prepared for each area to assess the impact on residents, landscapes, natural values, recreational use, and the regional economy.

Introduction to hydrogen economy in Joensuu Circular Park

The highlight of the meeting was the visit to Savon Voima Oy Iiksenvaara heating plant in Joensuu Circular Park. The CHP plant produces annually about 800 GWh of energy: district heat to City of Joensuu’s over 230 km long district heat network and electricity to national grid. Currently wood biomass makes ¾ of the plant’s fuel consumption while the rest is mainly domestic energy peat. Fossil oil is used only during startups and peak consumption during coldest periods.

The company's strategy aims to reduce direct biomass burning and eliminate peat usage by 2026, transitioning towards carbon-neutral energy production. Achieving these objectives relies on effectively harnessing waste heat sources and embracing opportunities within the hydrogen economy. A key initiative underway is the construction of a large 15,000 m3 heat storage facility, complemented by an extensive district heat network. This infrastructure serves as a buffer during peak heat demand, facilitating the utilization of diverse waste energy sources. Savon Voima is actively pursuing projects to recover local waste heat along the Joensuu district heat network. Moreover, the large heat accumulator serves as a strategic asset in the power capacity market, leveraging surplus renewable electricity to potentially drive electricity prices in the Nordpool market negative, rendering electric boiler heating the most economical option.

Savon Voima's power plant in Iiksenvaara is part of Joensuu Circular Park. Circular Park will bring together interesting activities in the near future, such as a hydrogen and biocoal production plants. Joensuu Biocoal torrefied biomass production plant is under construction and deeply integrated into Savon Voima CHP plant. It will be the Europe’s largest industrial-scale torrefied biomass production plant.

Torrefied biomass is a clean alternative to fossil raw materials, capable of directly replacing coal in existing industrial processes and power production. Once completed at the end of 2024, the plant reaches ca. 60,000 tons annual production of biocoal. Torrefaction process can refine various plant-based surplus / side streams and surplus materials, such as low-value fractions of the forest industry, into energy-dense products. This densification process produces excess heat, which will be used for district heating replacing burning of biomass.

The second big industrial waste heat source will be an industrial hydrogen production plant, of which plans are proceeding in permitting process. Water molecules will be decomposed/cracked in electrolysers to hydrogen and oxygen, and pure hydrogen is then further refined to carbohydrates like green methane or methanol. Source of carbon is CO2 captured from the plant’s chimney which makes the process carbon negative. Waste heat from electrolysers will be utilized in district heat network to further reduce biomass burning.

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Fresh Wood Chips as a Solution to the Energy Wood Shortage

The Natural Resources Institute Finland presented the Fresh Wood Chip project, aiming to enhance the climate efficiency and economic viability of using forest chips for energy. The project is crucial due to increased forest chip use following the Ukraine war and reduced peat use. The Fresh Wood Chip concept shifts from long storage and biomass loss to a resource-efficient chain using flue gas scrubbers, heat recovery, and boilers designed for higher moisture fuel. This approach accelerates inventory rotation, alleviates energy wood shortages, and maximizes energy yield from harvested wood by recovering waste heat and minimizing dry matter loss.

One good practice identified from North Karelia during the EXPRESS project is the renovation of the Arppe boiler house. The new Arppe heating plant utilizes the Fresh Wood concept in district heating production. Learn more: Arppe boiler house renovation cuts emissions and improves energy efficiency of biomass heat | interregeurope.eu