Photocycle targets low-cost energy storage with a clever hydrogen solution


For years, the solar power sector has struggled with inter-seasonal energy storage. The ability to harness surplus 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. Meanwhile, hydrogen, despite its clean-burning properties, has been sidelined due to 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 vision as bright as the summer sun, the startup claims its solid hydrogen-based technology can store energy more efficiently in an ammonia synthesis reactor. The claim is that this technology provides storage more cost-effectively than any battery or liquid hydrogen solution available on the market.

A scheme of how the photocycle visualizes its entire system when installed in a home. Image Credit: photocycle

“Lithium-ion batteries use expensive metals. Our stuff is very cheap: to store 10,000 kilowatt-hours, it costs about $1,500, so it's almost nothing. Plus, our storage solution is 20 times the density of lithium-ion batteries, and you don’t lose current,” founder and CEO Björn Brantzeg explained in an interview with TechCrunch. “This means we have a system where you can store energy over time, enabling seasonal storage. “This is a completely different thing from traditional batteries.”

The photocycle uses water and electricity to produce hydrogen. This in itself is not unusual if you have been following fuel cell vehicle technology. However, the company's approach includes an innovative twist: a reversible high-temperature fuel cell. This advanced fuel cell can produce hydrogen and generate electricity within the same unit.

The core of the photocycle's innovation lies in the treatment of hydrogen. They process 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 but also highly efficient due to the non-flammable and non-explosive nature of the solid state. This enables hydrogen storage at a density approximately 50% higher than liquid hydrogen, representing a significant advance in hydrogen storage solutions. These innovations form the cornerstone of the photocycle system, which facilitates safe and dense hydrogen storage, which the company says is a major step forward in energy technology.

Existing clean energy solutions such as rooftop solar are limited due to inconsistent supply due to the unpredictable nature of weather. A robust, reusable energy storage solution can meet these times, ensuring a stable energy supply when these renewable sources face inevitable intermittency periods.

Great in theory, but not without its challenges.

“The Netherlands is the country in Europe with the highest density of rooftop solar energy. We are now seeing massive increases due to high energy prices; Everyone wants rooftop solar,” says Brandzaeg. However, he says this approach can backfire for homeowners: “Last year in July, in the Netherlands, in the middle of the day, You have to pay €500 per MWh to export your electricity,

Generating electricity at home as well as storing energy allows homes to effectively go off-grid. Photoncycle says it has tested and worked out the main components of its solution – the next step is to integrate it into a single system. If successful, the company says it could seriously challenge Tesla's lithium-ion battery solution Powerwall.

David Gerges, Photocycle's CTO, and Ole Laugerud, a Photocycle chemist, have been in Photocycle's purpose-built laboratory, which has been operational for about two years. Image Credit: photocycle

“It's a relatively complex system – that's why we have so many PhDs in different disciplines working on it. The reason why Elon Musk said hydrogen is silly is because when you convert electricity into hydrogen and back again, you're losing a lot of energy,” Brantzeg says. He believes his company can turn this bug into a feature. “In a residential setting where 70% of energy needs are heating, there is an opportunity to use that excess heat to provide hot water. We will target markets where people are currently using natural gas for heating and then replace gas boilers in the home using existing water-fired infrastructure.

Brantzeg's confidence in the operational framework of the concept is compelling. He pointed to a small mock-up of their operation plant inside their laboratories, the size of a car battery. Brantzeg believes that this scaling should be problem-free, citing this as the primary reason he felt confident moving forward with the project.

When it comes to power delivery, hydrogen takes a while to generate electricity, so when it's moving around, the company relies on an intermediary, more traditional, battery for load balancing. The company certainly has investors' attention: photocycle has raised $5.3 million (€5 million) to build its first few electricity storage devices in Denmark, which Photocycle has chosen as its test market.

“Looking at the interest, we could have raised 10 times more than we could. But after this raise, I'm still the majority owner,” Brandtzeg says. “I wanted to keep control of the business for as long as possible and not raise more capital than necessary to bring this service to market.”