Kastrup startup aims to balance the grid with retired EV batteries

Gridturn in Kastrup aims to reuse end-of-life EV batteries as decentralized energy storage.

Last year, 1.4 million new electric vehicles were registered in the EU. Cars that symbolize CO₂-neutral driving and a contribution to the green transition – but also cars with an expiration date. According to McKinsey’s “Battery recycling takes the driver’s seat”, the number of used batteries is expected to grow by 25% annually towards 2040.

“We’re solving a climate challenge, but we’re also creating a waste problem. That’s not very circular – and that’s what we want to change,” says Louise Witt Sengeløv, chemical engineer from DTU and founder of the start-up company Gridturn, which is working to give EV batteries a new green afterlife.

Gridturn, which has been part of the Beyond Beta accelerator program in Energy Cluster Denmark, develops hardware and control software that make it possible to reuse EV batteries as decentralized storage units connected directly to the electricity meter.

“Decentralized battery units have countless use cases. They can balance the power grid, serve as backup, and enable peak shaving when connected to an EV or solar production – the potential is huge,” Louise Witt Sengeløv explains.

Low-hanging fruit

Reuse and recycling are among the best ways to address some of the toughest challenges in securing materials for the green transition. Trade barriers, supply security, and scarce raw materials don’t matter when the battery is already here.

Put simply, Gridturn integrates used EV batteries into a cabinet, adds hardware components and software – and suddenly you have energy storage.

“We see this as very low-hanging fruit. It’s genuine reuse, where the battery continues to function as a battery – just in a new context,” says Louise Witt Sengeløv. She hopes that more parts of the green value chain will begin to think circular, because the potential is significant.

“It requires collaboration across value chains and across a product’s lifetime. For example, solar panel manufacturers in China design their products with durability in mind – which makes sense, but it also makes them difficult to dismantle. As a result, many end up as roadfill instead of being recycled. If those who handle reuse could have a dialogue with those who produce, the entire value chain and resource use would benefit.

That’s why at Gridturn we work closely across the value chain to the benefit of all parties, and not least the green transition,” Louise Witt Sengeløv concludes.

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Participants will range from startups and established energy companies to municipalities, utilities, researchers and suppliers across the energy value chain.

The programme combines innovation site visits to selected energy projects in North Jutland, a networking dinner and the Annual Meeting conference at Aalborg Congress & Culture Center (AKKC) with keynotes, debates and workshops focusing on the technologies shaping the next phase of the energy system. The event will also feature the announcement of the Energy Cluster Denmark Innovation Award.

“Energy Cluster Denmark’s Annual Meeting brings the energy sector together to discuss and shape the future of green innovation. We provide both a professional overview of emerging innovation trends and a strong platform for building partnerships. Through our innovation tours, participants also get the opportunity to visit some of the technological solutions that are currently taking shape in practice,” says Glenda Napier, CEO of Energy Cluster Denmark.

On 12 May, participants can choose between two innovation tours. One takes place on the water and offers a unique perspective on Aalborg’s energy infrastructure and industrial landscape from the fjord, with insights from organisations including Aalborg Portland, Aalborg Forsyning and Port of Aalborg. The other tour heads north by bus to selected innovation environments and technologies already in operation, including SkyClean and Green Therma. The day concludes with a networking dinner where conversations and collaborations continue.

On 13 May, the Annual Meeting conference takes place at AKKC with presentations and debates focusing on the innovative solutions shaping tomorrow’s energy system. Participants will also have access to parallel sessions covering key innovation areas in the energy cluster, including wind standardisation, digitalisation of the energy system, CCUS, and batteries and energy storage. Participants will gain both strategic insights and concrete opportunities to engage in innovation projects and collaborations.

Speakers at the Annual Meeting include:

Henrik Stiesdal, founder of Stiesdall
Astrid Haug, author and speaker, presenting on citizen engagement in energy projects
Lasse Frimand, Mayor of Aalborg Municipality
Ann-Louise Andersen from Aalborg University
Tommy Bysted, CEO of Force Technology
Søren Møller, CEO of Dansk Salt
Kasper Roed Jensen, Vice President, New Concepts at Vestas
Caroline Bundgaard, Development Editor at Det Nordjyske Mediehus.

The Annual Meeting is open to stakeholders across the entire energy value chain, from startups and suppliers to industrial companies, utilities, municipalities and research institutions seeking to stay close to the latest knowledge and the partnerships that determine what gets scaled, standardised and implemented.

For members of Energy Cluster Denmark, participation in the Annual Meeting is free of charge.

03.06.26Registration open: Energy Cluster Denmark Annual Meeting brings the sector to Aalborg

Aegir Insights is taking a significant step in its development with the expansion of its Aegir Quant™ software. The tool now goes beyond offshore wind to include onshore wind, solar PV, energy storage, and hybrid energy systems.

With this move, the company shifts from being an offshore wind specialist to offering a full-spectrum decision-support tool across renewable technologies.

According to CEO Scott Urquhart, this expansion provides the market with a unified and standardized way to evaluate projects across technologies; a solution increasingly in demand as energy systems grow more complex and hybrid projects emerge as a key part of future energy infrastructure.

“The next phase of Aegir is about empowering the decision-makers shaping the energy transition,” Scott Urquhart says:

“By broadening Aegir Quant’s capabilities across all major renewable technologies, we’re helping investors and policymakers capture new value and build resilience in the clean-energy system.”

Building on collaboration

Over the past several years, Aegir Insights has established a global position as a provider of investment intelligence to developers, suppliers, investors, and public authorities.

The new version of Aegir Quant™ combines detailed techno-economic modelling with financial analysis, enabling stakeholders to benchmark, optimize, and finance next-generation projects with greater confidence.

The expansion builds on REALISE; a two-year research and development effort carried out in close collaboration with Vattenfall, the Technical University of Denmark (DTU), and Energy Cluster Denmark funded by EUDP, a program under Denmark’s national energy agency.

The partnership helped mature and validate the technology and is a fine example of how collaboration can accelerate progress in the green transition:

The REALISE project provided a solid foundation, with the combined work from industry and academia. We are now collaborating with forward-thinking partners across Europe, North America, and Asia-Pacific to apply the expanded Aegir Quant™ capabilities to real-world portfolios - focusing on bankability, portfolio optimization, and system resilience,” says Rikke Winther Nørgaard, CCO at Aegir Insights.

With the updated software, Aegir Insights aims to become the natural reference point for investment decisions in a sector where integration, flexibility, and system understanding are essential - and where hybrid solutions combining wind, solar, and storage may hold the key to higher returns and a more resilient energy system.

“Hybridization is redefining the economics of renewables and strengthening global energy resilience. From the point of starting the REALISE innovation project two years ago, we have seen ever increasing interest and adoption of hybrid renewable and storage projects. As this is just the beginning of the trend, we are excited to continue cooperating closely with developers and investors to improve bankability and returns on hybrid projects,” says Scott Urquhart, CEO at Aegir.

02.18.26From offshore wind to full renewable energy systems

The Danish startup Gridturn, which extends the life of used electric car batteries by converting them into certified battery energy storage systems (BESS), has been awarded EUR 75,000 in support from the Women TechEU program.

The support is given to female-led European technology companies with the potential to deliver significant innovation and sustainable transformation – and it is precisely this combination that makes Gridturn CEO Louise Witt Sengeløv happy:

"There is definitely no queue for the ladies' room when you go to energy-related conferences! There are few women in tech, but it is just a barrier that is extra motivating to break through. The support is a nice recognition and very inspiring for further work," she says.

Challenging the status quo

Gridturn's solution reduces waste and the need for new materials. This is what is needed:

"40 percent of the world's conflicts since the 1960s are related to the fight for raw materials. 90 percent of our biodiversity loss is related to raw material extraction, and we recycle far too little. In Europe we are at 12 percent circularity, in Denmark we are down to 4%. We must succeed in changing that," she says:

"At the same time, it is important that we make it economically sustainable. And yes, it may be difficult, but we have to do better and challenge the status quo," she says.

Gridturn's solution is to extend the life of electric car batteries so that they also have value when they are no longer suitable for electric cars:

"The range is crucial for a car battery, and therefore a reduction to 80 or 85 percent capacity effectively helps to retire the battery. But even with 80 percent capacity, the battery can still function and bring value if you place it in a different context. The batteries will do very well in our system. The ideal senior life," she says.

From waste to infrastructure

Gridturn recycles the batteries into battery energy storage systems (BESS), which integrate with existing energy solutions and help optimize consumption and balance the electricity grid.

This results in significant CO₂ savings, and the circularity is optimal: waste is turned into energy infrastructure.

Gridturn is now entering the market with a certified and scalable product line. A significant development for a startup that has been part of the Beyond Beta accelerator course in Energy Cluster Denmark.

“We hold the key to Europe’s future energy independence. By recycling batteries, we create a solution that is both greener, integrable and economically sustainable. I also hope that our journey can inspire more women to start deep tech companies – my two daughters are a big part of the motivation to lead this development,” says Louise Witt Sengeløv.

In addition to the funding, Gridturn will have access to a European mentoring and acceleration program that will strengthen business, technology and scaling.

02.12.26Gridturn receives European tech grant for groundbreaking solution for recycling electric car batteries

In order to examine the condition of wind turbine blades, inspections of blade damages are usually carried out when the turbine has been stopped. In the AQUADA-GO project, the partners have developed a drone technology for automated, contact-free, real-time blade damage detection, while the turbine is spinning. Inspections that are done without stopping the turbine’s normal operation can help save turbine downtime. Now, for the first time ever, the operational concept has been successfully demonstrated offshore.

“We have proven that it is possible to autonomously inspect offshore wind turbines with a drone of a certain size equipped with a visual camera, while the turbine is in operation. This is a major accomplishment for us. We have worked on everything from developing drone software and hardware to mission planning and online data infrastructure. Now, we have a commercially ready solution that can be tailored to wind farm operators’ needs and make inspections easier, faster and more cost-effective,” says Jesper Smit, CEO, Quali Drone.

Drone-based blade inspection delivers significant savings

The core idea of the project is to combine drone technology with thermography and computer vision, enabling detection of surface damage and potential subsurface fractures on operational offshore wind turbine blades. This saves wind farm operators considerable costs due to increased efficiency, while also reducing CO₂ emissions and improving inspection safety.

The new technology has been successfully demonstrated several times onshore by the project partners, which, in addition to Quali Drone and RWE, include Statkraft, TotalEnergies, DTU and Energy Cluster Denmark. Most recently, the solution has been demonstrated offshore with visual drone footage of blade damage on the surface at Rødsand 2 Offshore Wind Farm, operated by RWE since 2010 and located south off the coast of Lolland, Denmark.

“For the first time, we have successfully carried out a drone inspection of offshore wind turbines in operation. This is good news for the entire wind industry. Through the technology developed in AQUADA-GO, we can see the potential of monitoring blade conditions without stopping the offshore turbine. This could help to increase efficiency in our production of green electricity and to further improve safety for our employees. By using drones for autonomous inspections, we expect that downtimes and costs can be significantly reduced in the long run,” says Marcus Mejborn, General Manager of Rødsand 2 Offshore Wind Farm, RWE.

AQUADA-GO technology and AI model show great potential

The project is based on the AQUADA technology developed in DTU Wind Energy’s laboratory. DTU has developed an AI model that helps the drone automatically identify wind turbine blade abnormalities to indicate critical damage using AI algorithms and infrared imaging. The AI model, which is trained and improved with new inspection data each time the drone is deployed at wind farms, shows great potential.

“We have developed an AI model that uses deep learning algorithms and computer-vision technology based on thermomechanical models to assist the drone in detecting blade defects – both on the blade surface and below it. We have tested the technology multiple times at onshore wind farms operated by DTU, RWE and Statkraft, and each campaign has fed the AI model with new data that has made it better. We are very pleased with the results and see great potential for future implementation within the wind industry,” says Xiao CHEN, Associate Professor and Head of Section, DTU Wind and Energy Systems, and Project Technical Lead in AQUADA-GO.

Facts about the project

The AQUADA-GO innovation project runs from 2022 to March 2026 with a total budget of DKK 17,796,010 and is supported by EUDP – the Energy Technology Development and Demonstration Program. The project partners include Quali Drone, the Technical University of Denmark, RWE, Statkraft, TotalEnergies and Energy Cluster Denmark.