How SMRs could help decarbonise district heating
Small footprint, big heat
Warm, short summers, contrasted with long, dark, and cold winters. That is the climate of the Northern hemisphere in a nutshell, and one that those in the Nordic countries are very familiar with. That is why the Nordic countries have needed to come up with various solutions to the massively increased energy use, particularly for heating in the winter.
Written by Ingeborg Grötterud
District heating is a well-established solution, covering roughly 50% of the heating need in Sweden and Finland, as urbanisation has enabled its efficiency. These heat networks act as a system for distributing heat generated in a centralised location to entire cities. Heat is typically produced by a central plant using various energy sources such as fossil fuels, peat, biomass, municipal waste, or even waste heat from industrial processes.
As the energy system around us evolves, and we need to decarbonise, district heating solutions running on fossil fuels are no longer attractive options, nor are they likely to get funding, meaning new alternatives need to be implemented.
One such is perhaps a surprising solution: nuclear.
Small modular reactors – what are they?
SMRs are reactors with advanced engineered features that produce electricity of up to 300 MW(e) per module. They represent a new generation of nuclear technology, designed to offer scalable, flexible power and heat generation.
SMRs are deployable either as a single or multi-module plant and are designed to be built in factories and shipped to utilities for installation as demand arises. Unlike large nuclear plants, SMRs are intended for mass production with standardised components, allowing for faster construction and potentially standardised regulation. SMR technology has been in development for some time, and at the moment, we are seeing many SMRs at various stages of design, planning, or construction worldwide.
In Europe and the Nordic countries, a few key SMR initiatives are advancing rapidly from site selections and feasibility studies to initial environmental reviews – the first stage in the permitting process. For the early movers, anticipated operational dates are already in the mid-to-late 2030s. This is promising for district heating, where demand for clean heat sources aligns with SMR’s capacity to produce stable, carbon-free heat close to demand.
Real-world SMR initiatives in district heating
SMRs are particularly suited to district heating networks because of their ability to provide a continuous and stable heat supply. This is crucial for maintaining reliable heating in cold climates, where interruptions are costly and disruptive. Compared to fossil fuels, SMRs emit minimal greenhouse gases, supporting climate goals while reducing dependency on imported fuels a significant advantage for energy security in the Nordics and other regions.
The introduction of SMRs allows building nuclear plants closer to cities and this enables using SMRs for district heating. Several initiatives illustrate SMRs potential for district heating. In Finland, Steady Energy is pioneering an SMR concept specifically for district heating and low-temperature industrial applications. Several cities have already indicated their interest in this concept. The LDR-50 concept was conceived at the VTT Technical Research Centre of Finland. The researchers found out that almost 10% of all CO₂ emissions originated from heating up water or steam to 150° C.
While developing the concept, we realised that the LDR-50 had enormous commercial and environmental potential, and so Steady Energy was born in May 2023. We are now focused on commercialising the technology with the aim of decarbonising district heating, desalination, and certain industrial activities.
– Tommi Nyman, CEO of Steady Energy.
Steady Energy, along with the Swedish firm Kärnfull Next, plans to bring the LDR-50 to the Swedish district heating market, working with municipalities and industry leaders to phase out biomass and fossil fuels. Kärnfull Next has already signed MoU to start pre-feasibility studies and anticipates significant environmental and economic benefits from decarbonising heat supply.
As a leading scale tech project developer, we develop the initial idea into a fully licensed, financed, and ready-to-build project and we recognise the vast opportunities within Swedish municipalities. LDR-50 is a key enabler to decarbonise the district heating systems in an efficient way giving consumers value for their money. As the drive to reduce dependence on biomass intensifies, we are already commencing our initial pre-feasibility studies, leveraging the straightforwardness of the LDR-50 to pave the way for a more sustainable and predictable business.
– John Eliasson, Business Development Manager at Kärnfull Next.
In addition to Steady Energy, there are numerous global initiatives exploring various SMR solutions. For instance, GE Hitachi's BWRX-300 is promoted as a cost-competitive option for electricity generation and industrial applications, including hydrogen production, desalination, and district heating. For large cities around the world, combined heat and power produced by larger SMR plants could be a viable option.
Addressing the challenges: costs and public acceptance
Despite these promising developments, the transition to SMR-based district heating involves hurdles. High initial investment costs, including reactor construction, installation, and integration with existing heating networks, can make SMRs financially challenging. To alleviate this, extensive feasibility studies and innovative financing models will be essential to ensure that projects are thoroughly evaluated and economically viable.
SMRs rely and standard, modular design and project-specific changes on the design should be minimised. This requires a harmonised licensing approach, which would allow building a similar plant in several locations or countries. Adapting the current regulation to better enable SMR projects is a challenge to overcome.
In Finland and Sweden, the public acceptance for nuclear and SMRs is nowadays high. However, like with most energy production technologies, sometimes those who are in general in favour of the solutions might end up taking a “not in my backyard” stance if they are not engaged enough in the decision-making process. That is why open and transparent communication will be essential to build community trust.
Path forward for SMRs in decarbonising district heating
The potential for SMRs to contribute to district heating is significant, offering a clean, reliable alternative to combustion-based technologies. As SMR projects pro-gress and regulatory frameworks adapt, these reactors could become a main-stream solution for heat generation in Nordics and Europe by the next decade.By addressing key challenges and continuing to develop SMR initiatives, the Nordics – and other regions – could achieve an innovative leap toward sustainable, de-carbonised heating, providing lasting environmental and economic benefits.
