What if electricity isn't always a given? DENS has the solution
Battery manufacturer DENS is growing rapidly. Its high-quality batteries provide power in places where it is not readily available.
Published on May 26, 2025

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The Dutch electricity grid is completely congested. According to figures from Netbeheer Nederland, at the end of 2024, nearly 12,000 large-scale consumers were waiting for a connection to the power grid. In addition, there were more than 8,000 requests to feed electricity back into the grid. Consumers also have to wait longer and longer for a connection, currently 40 weeks on average. At the same time, electricity demand is only increasing, partly due to sustainability efforts. Scaleup DENS is developing various battery solutions to tackle these problems. “People need to start looking at electricity as a raw material that is not always available,” says Tijn Swinkels, co-founder and CEO of DENS.
“We have to take into account that electricity will not always be available. We may have to bridge a few hours or even a day without power,” Swinkels continues. In addition to grid congestion, he also refers to the recent massive power outage in Spain and Portugal. "It's bizarre what happens when a country has no power for a day. Our product can help to supply critical facilities—not just hospitals and fire stations, but also production sites in the food industry, for example—with power during such blackouts. We are currently investigating exactly how this should be done."
Growing demand
At present, DENS products are mainly used on construction sites. Companies also use DENS battery systems to store peak outputs from renewable energy for later use, thereby offering a solution for grid congestion.
The company located at the Helmond Automotive Campus noticed a surge in interest in battery storage solutions in recent years. In 2024, turnover grew by 130% compared to the previous year. To meet the increasing demand, the company has increased production speed in the factory fivefold over the past year. "We use the space in our factory very efficiently, but we are now reaching the limits of the building. That is why we are busy expanding our production space," says Swinkels.
Reliable
The company is now active in three market segments. The first is mobile battery systems, which are often equipped with integrated fast chargers for electric trucks or equipment on construction sites or for electric dredging on ships. The second is stationary battery systems, which are used to solve problems related to grid congestion. The third segment concerns integrated solutions, which are customized battery packs for machine manufacturers who use the systems to electrify their machines.
What sets DENS apart from other battery companies? “The reliability and quality of our products are critical to our customers,” says Manon Perez, CFO at DENS. Swinks continues: “In two and a half years, we have secured contracts with the top eight construction companies in the Netherlands. This industry is a small world, and stories about new products spread quickly. This means you can build up a good reputation relatively quickly, but trust is also quickly lost if you don't deliver a good product.”
Another essential factor for their customers is that DENS battery systems are manufactured in Helmond. Perez: “We see that companies are less inclined to choose systems from China, for example. We stand out regarding complex or critical projects and locations.”
Hydrozine
Several components in DENS batteries result from the development of an entirely new innovation by the company: the Hydrozine generator. Hydrozine – also known as formic acid – is a liquid, organic hydrogen carrier. The Hydrozine generator can be used when ordinary batteries are no longer sufficient. “If you can drive back and forth every day to recharge a battery, that's the best and cheapest solution. If that's not possible, Hydrozine can be the right option,” summarizes Swinkels. Consider, for example, a ship that is at sea for days on end. “You can't take batteries with you for such a long time; they're far too heavy. Hydrozine is a good solution in that case,” he says.
From student team to startup
The DENS team has been working on the development of Hydrozine for years. It started with Team FAST, an Eindhoven University of Technology student team. "Between 2015 and 2018, we tried to build a bus powered by Hydrozine together with VDL. Initially, we had no idea what we were doing; we had no money or people, but we did have sky-high ambitions. We got pretty far with that. The system with Hydrozine as an energy source worked, but we couldn't get it to run. That was the next step," Swinkels recalls. The decision was to discontinue the automotive application and focus on a stationary system. “Alongside construction company BAM, we built a Hydrozine generator that was used in the construction of the N211-a road in the province of South Holland, ed. Max Aerts and I found this so valuable that we further commercialized it.”
That's how the startup DENS was born. Money was needed to develop the products further. At the time, in 2018, Rabobank was the first to decide to invest in Aerts and Swinkels' company. “That got the ball rolling, because after Rabobank's investment, other parties followed suit. An investment from a bank also inspires confidence,” says the CEO.
Knowledge and network
It was an important step for the startup, but also for the bank. DENS was one of the first companies to receive the Rabo Innovation Loan. “With this loan, we want to help startup entrepreneurs who contribute to important social transitions, such as the energy transition in this case,” says Vincent Ruis, startup and scaleup banker at Rabobank.
“This allows Rabobank to take more risks than other large banks. It requires a different way of thinking,” adds Swinkels. Ruis: “The recent development that DENS has undergone perfectly illustrates why we offer such innovative loans. We mainly look at the potential of innovative and disruptive companies.”
In addition to financing, the bank also supports entrepreneurs with knowledge and networking. Jeroen Claeijs, account manager for large businesses at Rabobank: “When I talk to customers looking for an energy solution, I can connect them with DENS, for example. That way, we help everyone take a step forward.”
Trade war causes uncertainty
Swinkels, therefore, sees Rabobank as an essential partner, especially in the current uncertain economic climate. The trade war between the US and China is causing insecurity, he says. "It's a constant balancing act: what risks do you take and how do you deal with them? We analyze various scenarios – for instance, when it comes to purchasing and stocking materials – and then look at what the best option is at that moment. With complex issues like these, I regularly call the bank. It's nice to talk to someone who knows the market well.“ There is no ready-made solution to the geopolitical turmoil. Swinkels: ”For now, it's mainly a matter of staying calm. We gather as much information as possible and make well-thought-out decisions."
Rollout and scaling up
DENS is now focusing on rollout and scaling up. In the coming months, the team wants to ensure that the technology for the Hydrozine generator works well and is reliable. “I'm getting married at the end of the summer and we want to use the generator at the wedding, so it has to work properly,” laughs Swinkels. "After that, several promising pilots are lined up to test it further. If all goes well, we want to enter the market and scale up further.” Swinkels wants to continue rolling out the battery systems on the European market in the coming period. ”The Netherlands and Scandinavian countries are seen as pioneers in the field of battery technology. That also gives us a good starting position in other countries."
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