20 times denser than lithium-ion batteries! A solid hydrogen-based energy storage solution

Photoncycle has developed an energy storage solution based on solid hydrogen that is 20 times denser than lithium-ion batteries.

In the solar sector, storing energy across seasons has always been a challenge. Harnessing excess solar energy from summer to winter has always been a very elusive goal, and existing solutions, such as batteries, are inadequate due to high costs and limited lifetimes. Despite its clean-burning properties, hydrogen has been relegated to the background due to its low efficiency and high cost.

Photoncycle, a startup from Norway, has been working on a solution. The startup claims that its solid hydrogen-based technology can store energy more efficiently in ammonia synthesis reactors. This technology is expected to achieve more economical energy storage than any battery or liquid hydrogen solution on the market.

Lithium-ion batteries have to use expensive metals. The company's product is super cheap: it costs about $1,500 to store 10,000 KWh, so it's almost nothing. It has 20 times the storage density of lithium-ion batteries, and it doesn't drain the battery. A system that can store energy for a long time, allowing seasonal storage. It's completely different from traditional batteries.

Photoncycle uses water and electricity to produce hydrogen. If you know anything about fuel cell vehicle technology, this isn't uncommon. However, the company's approach includes an innovative twist: a high-temperature reversible fuel cell. This advanced fuel cell can produce hydrogen and electricity in the same unit.

At the heart of Photoncycle's innovation lies the processing of hydrogen. They process hydrogen and then use their technology to convert it and store it in a solid state. 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. It allows hydrogen to be stored at a density that is approximately 50% higher than liquid hydrogen, which is a significant advancement in hydrogen storage solutions. These innovations form the cornerstone of the Photoncycle system and facilitate safe and dense hydrogen storage, which the company says is a major step forward in energy technology.

Current clean energy solutions, such as rooftop solar, are limited by inconsistent supply due to unpredictable weather conditions. A robust and reusable energy storage solution can bridge these gaps, ensuring a steady supply of energy during the inevitable intermittent periods faced by these renewable energy sources.

Placing an energy storage system next to a house that effectively generates electricity can allow the house to go off the grid. Photoncycle said it has tested and researched the core components of its solution, and the next step is to integrate it into a system. The company said that if successful, it will challenge Tesla's lithium-ion battery solution Powerwall.

The Photoncycle system is based on the following features:

Electricity generation for a single-family home:

In Europe, rooftop photovoltaic panels typically generate 4-15 times more electricity in summer than in winter. However, in turn, energy demand for electricity and heating in winter is 2-3 times higher than in summer.

Challenges facing distribution networks:

As more households install rooftop photovoltaics, it becomes increasingly difficult for distribution networks to accommodate excess electricity in the summer. In addition, rising winter electricity demand due to the decarbonization of heating and the shift to electric vehicles is also putting pressure on the grid infrastructure.

Photoncycle energy storage technology:

Develop a technology that can put surplus electricity from rooftop photovoltaics and the grid into a long-term energy storage system next to the house using an electrolyser. Green hydrogen produced from water and electricity is stored in solid form in the system developed by Photoncycle. Energy is released on demand to meet electricity and heating needs at household and grid level.

Gravimetric energy density:

Photoncycle's energy storage solution has a gravimetric energy density of approximately 3.5kWh/kg, compared to 0.3kWh/kg for lithium-ion batteries. The high gravimetric and volumetric energy density combined with low energy storage costs paves the way for affordable seasonal energy storage at the household level.

Energy storage capacity:

The 3m³ storage system can store up to 10,000KWh of energy, enough to store all of the excess electricity most households have during the summer.

Utilize the potential of your roof:

This technology will allow households to use the full potential of their rooftops for energy production, using solar PV internally. Long-duration energy storage will allow households to take advantage of seasonal fluctuations in energy prices, importing electricity from the grid when prices are low and exporting it to the grid when prices are high.

Development and Validation:

Based on a feasibility study conducted by SINTEF, a leading European scientific research institute, a team of Photoncycle engineers and scientists developed and validated the individual components for its system in 2022. In 2023, these were integrated and scaled up into a working prototype of its core technology in the Photoncycle lab. A full-scale pilot will follow in 2024, and the first product will be launched on the residential market in 2025.

System patent:

The system patent was submitted to the European Patent Office in June 2021. In October 2022, the European Patent Office confirmed that the technology developed by Photoncycle is novel and inventive, two criteria for obtaining a patent. The patent application will enter the national approval stage in early 2024.

(Source: Photoncycle Global Hydrogen Energy Network, New Energy Network Comprehensive)