SusWoodStoves - Sustainable wood stoves through stove, building integration and value chain optimisation

SusWoodStoves, with its focus on sustainable wood stoves, is a response to the open Research Council of Norway KSP call and the topic Environment-friendly energy and its focus on the long term, sustainable development of the energy system, that enhance the competitiveness of Norwegian trade and industry and accelerate the transition to a low-emission society, including reducing anthropogenic greenhouse gas emissions. It is also directed towards the ENERGIX program plan and its focus on

1. sustainable utilisation and consumption of renewable energy resources - as biomass
2. reduction of Norwegian and global emissions of greenhouse gases - from bioenergy
3. enhancement of Norway’s security of supply - through increased use of domestic biomass resources
4. strengthened innovation in Norwegian trade and industry and the public sector - for the wood stove value chain
5. further development of Norwegian research and educational institutions - to be able to support innovation efforts in the wood stove industry.

Bioenergy is important in Norway and the current national bioenergy strategy is influenced by e.g. Klimakur 2030, Klimameldingen¹, Bioøkonomistrategien², Energi21 and Skog22. Wood log combustion has long traditions in Norway, constituting above 40% of the total use of biomass for stationary energy purposes, and accounting for about 12% of the domestic heating.

Using wood logs is important for security of supply in Norway, where we today rely heavily on the electricity grid to deliver the needed space-heating for our houses, which are typically wooden (with relatively low thermal mass). With a high nominal power, wood stoves can significantly reduce power peaks in the electricity grid, prevent blackouts and act as backup heating system. In a context of increasing electricity use in households, including electric cars, reducing peak electric power is strategic as it enables to prevent or postpone large investments to reinforce the distribution grid. New houses, as well as retrofit/upgrading of old houses, have increasingly focused on improved energy efficiency (e.g. the Norwegian passive house standard³, the TEK17 regulation and nearly-zero energy buildings from 2020, NZEB). The space-heating effect (power) required for these highly-insulated buildings is drastically reduced, which means that wood stoves for these buildings should be able to deliver a close to constant heating effect to the building as low as ~1 kW, which is much lower than for a new stove in an old house.

Combining heat production, storage and distribution in an optimum way, would make it possible to achieve a substantially more stable heat release and distribution, and with lower heating effect. This was a key focus of the knowledge-building projects StableWood (2011-14) and WoodCFD (2015-18), the predecessors to SusWoodStoves. The StableWood studies confirmed that wood stoves have a place in future’s buildings, while WoodCFD progressed the knowledge and especially modelling tools significantly, to enable improving wood stoves with respect to emissions and energy efficiency, as well as combustion stability and optimum room and building integration. Additionally, FME CenBio (2009-17) made a first effort to assess the wood stove value chain, comparing old and new wood stoves, at nominal and part load operation.

However, to ensure a sustainable wood stove future both in the existing building stock and the residential buildings of the future, further knowledge building within emission reduction, energy efficiency increase, proper building integration, and value chain, techno- and socio-economic assessments is needed. This will secure the continued use of wood stoves as an important, comfortable and sustainable heat source in the existing building stock (replacing old/poor stoves) and the residential buildings of the future, providing also substantial socio-economic benefits. Therefore, SusWoodStoves is established.

1. Klimameldingen - St.meld. nr. 21 (2011–2012) & St.meld. nr. 41 (2016–2017);
2. Kjente ressurser - uante muligheter - Regjeringens bioøkonomistrategi (2016);
3. NS 3700 Criteria for passive houses and low energy buildings - Residential buildings, 2013 (In Norwegian)