For years, the solar energy sector has struggled with storing energy between seasons. The ability to harness the excess solar energy of the summer months for use during the winter remains an elusive goal, with existing solutions such as batteries falling short due to prohibitive costs and limited lifetimes. Hydrogen, meanwhile, despite its clean-burning properties, has been sidelined by inefficiency and high cost.
Photoncycle—a startup emerging from the depths of an accelerator at the Oslo Science Park in Oslo, Norway—is working on a solution. With a vision as bright as the summer sun, the startup claims solid hydrogen-based technology can store energy more efficiently in an ammonia synthesis reactor;. The claim is that this technology makes storage more economical than any battery or liquid hydrogen solution on the market.
A schematic of how Photoncycle envisions its complete system when installed in a home. Image Credits: Photocycle
“Lithium-ion batteries use expensive metals. Our hardware is extremely cheap: To store 10,000 kilowatt-hours, it costs about $1,500, so it’s next to nothing. In addition, our storage solution is 20 times the density of a lithium-ion battery and you don’t lose power,” explains founder and CEO Bjørn Brandtzaeg in an interview with TechCrunch. “That means we have a system where you can contain energy over time, allowing for seasonal storage. It’s something completely different from traditional batteries.”
The Photoncycle uses water and electricity to produce hydrogen. This in itself is not unusual if you follow fuel cell vehicle technology. However, the company’s approach incorporates an innovative twist: a reversible high-temperature fuel cell. This advanced fuel cell can produce hydrogen and generate electricity in the same unit.
The core of Photoncycle’s innovation lies in hydrogen processing. They process the hydrogen and then use its technology to convert and store it in solid form. The company claims that this storage method is not only safe, due to the non-flammable and non-explosive nature of the solid state, but also highly efficient. It enables hydrogen storage at densities approximately 50% greater than liquid hydrogen, representing a significant advance in hydrogen storage solutions. These innovations are the cornerstone of Photoncycle’s system, facilitating the safe and dense storage of hydrogen, which the company says is a huge step forward in energy technology.
Current clean energy solutions, such as rooftop solar, are limited by inconsistent supply due to the unpredictable nature of weather conditions. A robust, reusable energy storage solution could bridge these timings, ensuring a stable energy supply when these renewables face inevitable intermittent periods.
Great in theory, but not without its own challenges.
“The Netherlands is the country in Europe with the highest rooftop solar density. We are seeing a huge ramp up now due to high energy prices. everyone wants rooftop solar,” says Brandtzaeg. He adds, however, that this method can backfire on homeowners: “In July last year, in the Netherlands, in the middle of the day, you had to pay 500 euros per megawatt hour to export your electricity.”
Placing energy storage alongside the home that generates electricity lets homes go off the grid. Photoncycle says it has tested and worked out the main components of its solution — the next step is to integrate it into a system. If successful, the company says it could seriously challenge the Powerwall, Tesla’s lithium-ion battery solution.
David Gerez, CTO at Photoncycle, and Ole Laugerud, who is a Photoncycle chemist, in Photoncycle’s purpose-built lab, which has been in operation for almost two years. Image Credits: Photocycle
“This is a relatively complex system — that’s why we have so many PhDs in different disciplines working on it. “The reason Elon Musk said hydrogen is stupid is because when you convert electricity into hydrogen and vice versa, you lose a lot of energy,” says Brandtzaeg. He believes his company can turn this bug into a feature. “In a residential environment where 70% of energy needs are heating, there is an opportunity to use this excess heat to provide hot water. We will target markets where people currently use natural gas for heating and then replace the gas boiler at home using existing water-based infrastructure.”
Brandtzaeg’s confidence about the operational framework of the idea is compelling. He gestured to a small model of their operating plant inside their labs, about the size of a car battery. Brandtzaeg believes this scale-up should be seamless, citing it as the main reason they felt confident moving forward with the project.
In terms of power supply, it takes a while for the hydrogen to generate electricity, so while it is being recycled, the company relies on an intermediate, more conventional, battery to balance the load. The company certainly has the attention of investors: Photocycle just raised $5.3 million (€5 million) to build the first energy storage devices in Denmark, which Photoncycle chose as a test market.
“We could have raised 10 times what we did, given the interest. But after this increase, I still own the majority,” says Brandtzaeg. “I wanted to keep control of the business as much as possible and not raise more capital than we need to bring this service to market.”
