Norwegian climate tech startup Photoncycle has secured €15 million in Series A funding to scale its hydrogen-based seasonal energy storage systems, designed for residential buildings in Denmark and the Netherlands.
Founded in 2020 by CEO Bjørn Brandtzæg, Photoncycle’s technology converts surplus solar electricity generated during the summer into hydrogen. This hydrogen is stored in a solid-state form in underground tanks with capacities of around 10,000 kWh. When households need energy during the winter, the hydrogen is converted back into electricity via fuel cells, with recovered heat available for space heating or hot water through a heat pump.
The integrated system combines solar panels, a hydrogen processing unit, storage tanks, a fuel cell, and short-term batteries, all managed by software that optimizes energy usage, storage, and trading across seasons.
“The Netherlands has one of Europe’s most advanced rooftop solar markets. The next step is solving the seasonal mismatch. As net metering is phased out, households will need new ways to retain the value of their summer solar production rather than exporting it to the grid,” explains Bjørn Brandtzæg, Photoncycle’s CEO.
The Series A round was led by NordicNinja and Voima Ventures, with participation from existing investors Lifeline Ventures, Eviny Ventures, Luminar Ventures, and Momentum. NordicNinja General Partner Tomosaku Soharahighlighted the opportunity to bridge Japanese capital and European startup expertise to strengthen energy sovereignty globally.
Photoncycle plans to use the funding to scale manufacturing, aiming for a 1.4 TWh annual production capacity starting in 2027, and to support early deployments in Denmark before expanding into the Netherlands. This approach positions the company to help solar households store excess summer energy for winter use, addressing a growing challenge as net metering policies change.
