The limited availability of green Hydrogen still stands in the way of broad deployment of this energy carrier. The Dutch-based techcompany DENS is tackling this problem at its core, namely by developing a generator that produces hydrogen, and then converts it into electricity. It isalso developing powerful battery systems.
Since 2018, DENS has been developing the Hydrozine generator. Inside, the liquid hydrogen carrier Hydrozine, also known as formic acid, is converted into hydrogen, which in turn is used to produce electricity. It is a high-tech innovation process with which DENS has already generated much notoriety at home and abroad. While plenty of work is being done to develop the Hydrozine generator, DENS has also recently been focusing on another product: battery systems.
In early 2023, the young company delivered the world's largest mobile battery container to a construction site in Breda,the Netherlands. With a capacity of 2.3 MWh, enough to power a household for a year, electric excavators and other machinery are charged on site. And it does so in a relatively modest 6.5 by 2.5 by 2.5 meter enclosure. The container comes as a 20-foot flatrack with a hook-lift system, so no separate crane is needed to load - and unload - the container. This allows the Powerhub to be installed or retrieved within 1 minute.
Preventing battery fire
Why the change in direction from Hydrozine generators to battery packs? According to Max Aerts, CEO of DENS, it was a logical move.
"The core of DENS has not changed, the focus is still on the Hydrozine generator. But the generator also includes a battery pack and we have now started marketing that as a separate product aswell. We are convinced that Hydrozine has great added value in the energy transition, but in places with a grid connection nearby it pays to use a battery pack instead."
This is not new, Aerts emphasizes, only that until recently the young company lacked the space to work on two tracks. Now it can. "We have grown rapidly: from 20 people in 2021 to over seventy people now. We also have new premises where we have set up a complete production line to mass produce both generators and battery systems. Until 2021 we have been full steam ahead with development, now we can start production.
The battery systems are identical to those in the Hydrozine aggregates. The unique aspect of DENS' battery system is its high safety standard and compartmented design, with each 145kWh having its own safety sensor and fire suppression system built in . "If a problem occurs in such a fire compartment that sensor ensures that a fire suppressant is activated preventively, says Aerts. In this way, a chemical instability can be prevented from degenerating into a so-called "thermal runaway," a culmination of chemical reactions that makes battery fires so difficult to control. "We pay a lot of attention to the chemical aspect of battery systems, which is sometimes still underexposed," says Aerts. "First and foremost, it has to be safe." For machines up to about thirty tons, he foresees an electric future. After that, hydrogen ls full-fledged alternative comes around the corner. "That can be in a combustion engine, but also as an energy carrier in our own Hydrozine generator. In the future, we also want to apply that directly to machines."
According to Aerts, Hydrozine may well play a major role in the energy transition. After all, for now hydrogen is mainly produced using natural gas. According to central government figures, this process produces 13 megatonnes of CO2 per year. "As long as green hydrogen is still in short supply, you can't really consider it a clean alternative. But as complex as the technology behind our generators may sound to outsiders, it can be reduced to one simple fact: we make hydrogen.
'Powerhub for all-electric machinery'
Meanwhile, the development of the DENS battery systems continues. "The battery system we delivered in Breda is equipped with a charging station for fast-charging, can be recharged via the fixed power grid, but also via solar or wind energy, and complies with the grid code, so that trading on the imbalance market is possible. As a result, you can basically talk about a power hub that you can use for the entire electrical machinery in many locations that are close to the grid."|
In discussing alternative energy sources, Aerts stresses, it is important not to lose sight of the higher goal.
"The energy transition sometimes looks like a technological race but we have to be aware that we don't want a winner here. It is very important to invest and develop on all the different tracks - electric, Hydrozine, hydrogen gas, biogas, you name it. There is not a single solution for all fields of application: the world demands different energy sources and they must all be there soon, each within the segment in which they perform best."