United for green innovation

Used EV batteries may soon take on a new role in stores: as energy storage, backup power and flexibility for an energy system in transition. That is the ambition behind the innovation project ReStoreBESS.

The project is led by Gridturn in collaboration with Salling Group, Andel Energi, Converdan and AAU Energy, and facilitated by Energy Cluster Denmark. The project is supported by EUDP.

The solution will be tested in a Salling Group store, where it will combine intelligent control, backup power and grid support in one integrated platform.

Unlocking the remaining value in used EV batteries

For Gridturn, the key point is that the batteries should not only be reused. They should be used intelligently.

“We develop battery systems made from used EV batteries that can both optimise daily operations and provide backup power if the electricity goes out. This is exactly the kind of solution we need right now: something resilient, green and more intelligent,” says Louise Witt Sengeløv, CEO of Gridturn.

In the project, used EV batteries that are no longer attractive for driving are given a new purpose, as they still hold significant value as stationary energy storage. The batteries are installed in cabinets and connected to solar panels and intelligent control systems, enabling them to charge and discharge at the right times. This will create value in daily operations and make stores less vulnerable if the power supply fails.

“If we think of critical infrastructure as places where power cannot be gone for very long, this solution makes a lot of sense. The system can optimise daily operations and switch to backup when needed,” says Louise Witt Sengeløv.

Cooling and freezing as critical store functions

Stores are an obvious place to demonstrate the technology. They have high energy consumption, local solar production in many cases, and critical functions such as cooling and freezing, which cannot tolerate longer power outages.

“Security of supply is on everyone’s agenda, and that is why it makes perfect sense for Salling Group to take part in ReStoreBESS. We see this as a project where we can learn from the technology in operation and test the potential for scaling, safety and robustness,” says Martin Brix Kortegaard, Senior Energy & Sustainability Manager at Salling Group.

For Salling Group, the perspective goes beyond the test store itself. If the solution works in practice, it could become relevant on a much larger scale in the future.

“For us, this is not only about a traditional business case. It is also about supporting green technology and ensuring that our stores become less vulnerable to short-term power outages, which we must expect to see more of,” says Martin Brix Kortegaard from Salling Group.

Energy should not only be green - it should also be secure

At the same time, the ambition is that the batteries should not only support the store, but also the wider energy system. By charging and discharging intelligently, the batteries can make better use of local solar power, relieve pressure on the electricity grid and, in the long term, contribute flexibility when the energy system needs it.

“The ideal situation is that the customer experiences a battery that supports everyday operations, while also making it possible to contribute when the energy system needs support,” says Jack Kristensen, Head of Flexibility at Andel Energi. He points out that the energy debate has changed significantly.

“Energy is no longer only about being green. It also has to be secure, and it has to remain affordable over time. This is exactly the intersection that the project addresses,” says Jack Kristensen. He adds that the project also builds on an existing collaboration between Andel Energi and Gridturn.

“We see a strong commitment to developing new solutions that are both innovative and make sense in a circular economy. At the same time, as an established company, we can help bring new solutions to the market,” says Jack Kristensen.

In the bigger picture, the project may point to a new direction for stores and other commercial sites: reduced vulnerability, better use of green electricity and a more flexible electricity grid. All with used EV batteries as part of the solution.

The award was presented at Energy Cluster Denmark’s Annual Meeting on 13 May 2026 in Aalborg to Peter Lindholst, Strategic Business Developer, Stiesdal, representing SkyClean Scale-up. The award followed a live vote in which 300 participants in the audience could vote for their favorite among the three nominated innovation projects: FOD4Wind, PACMAN, and SkyClean Scale-up.

“It is a great honor to receive the Innovation Project of the Year 2026 award from Energy Cluster Denmark on behalf of the project. Through SkyClean Scale-up, we have succeeded in creating a pyrolysis plant of commercially relevant scale and utilizing biogenic resources that otherwise would not have been used today to generate energy and carbon storage. All of this has happened through close collaboration among a broad group of partners from companies and knowledge institutions across the energy and agricultural sectors,” says Peter Lindholst, Strategic Business Developer, Stiesdal.

United for green innovation

Glenda Napier, CEO of Energy Cluster Denmark, had the honor of presenting the award to this year’s winner. The Innovation Project of the Year 2026 award is given to a project within Energy Cluster Denmark that, over the past year, has demonstrated unique collaboration on energy technology innovation benefiting industry and the green transition.

“We need innovative partnerships across the energy sector to strengthen the sector’s competitiveness and create real green impact. The collaboration in the SkyClean Scale-up innovation project is a strong example of this. Therefore, I am pleased to present the partnership with the Innovation Project of the Year 2026 award at our Annual Meeting in Aalborg together with 300 members of the Danish energy cluster,” says Glenda Napier, CEO, Energy Cluster Denmark.

Pyrolysis on an industrial scale

Stiesdal inaugurated the world’s largest 20 MW pyrolysis plant in October 2024 in Vrå as part of the SkyClean Scale-up innovation project. The plant uses biogas residue fibers from the biogas facility Agri Energy Vrå and produces biochar for carbon storage as well as green energy to replace fossil fuels. Each year, the plant can store up to 28,000 tonnes of CO2 through biochar production and displace natural gas emissions equivalent to 9,500 tonnes of CO2.

Researchers from five Danish knowledge institutions have investigated everything from the stability and quality of biochar to the effects of biochar on agriculture, soil ecosystems, and the climate. The research confirms that biochar produced through pyrolysis provides stable long-term carbon storage in agricultural soils, and that biochar has soil-improving properties and can serve as an effective alternative fertilizer.

Facts about SkyClean Scale-up

SkyClean Scale-up ran from 2022 to 2025 with a total budget of DKK 200,582,061. The innovation project received funding from the Danish Energy Agency’s Pyrolysis Fund, financed by the European Union under the NextGenerationEU initiative. The partners included Stiesdal, Agri Energy Vrå, KK Wind Solutions, Topsoe, Technical University of Denmark, University of Copenhagen, Aarhus University, Roskilde University, SEGES Innovation, Food & Bio Cluster Denmark, and Energy Cluster Denmark.

The partnership spans turbine manufacturers and project developers to vessel operators, logistics and port players, as well as specialists in lifting, rigging and engineering.

Most recently, Ørsted has joined the collaboration to help strengthen industrialization and make projects more predictable, reducing unnecessary customization, iterations and “one-offs” in the installation phase.