Photoncycle raises €15M to bring seasonal energy storage to the Netherlands ahead of 2027 net metering phase-out
Elina Koivisto
- €15M Series A to support commercial launch in Denmark and the Netherlands as Dutch solar households prepare for end of net metering
- First phase of 1.4 TWh annual manufacturing capacity planned for 2027
- Subscription model aimed at lowering upfront costs for Dutch homeowners
Wednesday 4 March, 2026: Norwegian energy storage scale-up Photoncycle has raised €15M in Series A funding to accelerate the commercial rollout of its seasonal solid-state hydrogen-based energy storage system in Denmark and the Netherlands. The round was led by NordicNinja and Voima Ventures, with participation from existing investors Lifeline Ventures, Eviny Ventures, Luminar Ventures and Momentum.
The funding comes as the Netherlands prepares to phase out net metering in 2027, a policy change that will significantly alter the economics of rooftop solar. Dutch households have one of the highest rates of solar panel adoption in Europe, resulting in substantial summer overproduction that is currently fed back to the grid. As net metering ends, households will increasingly need to store or self-consume surplus solar energy rather than relying on the grid as a seasonal buffer.
Photoncycle’s system is designed to enable households to store excess summer solar power for use during winter, when heating demand peaks and electricity prices are typically higher. The company aims to provide lower and more predictable year-round energy costs by reducing exposure to volatile winter gas markets and rising grid tariffs.
The Netherlands is also facing growing grid congestion challenges, with network operators warning of capacity constraints in multiple regions. Distributed, household-level seasonal storage could help reduce pressure on local electricity networks by retaining more energy onsite rather than exporting it during peak solar production periods.
At full industrial scale, Photoncycle’s planned 1.4 TWh annual manufacturing capacity — expected to begin coming online in 2027 — would represent storage capacity equivalent to roughly 140,000 homes each storing 10,000 kWh of seasonal energy. The company intends to begin commercial deployment in Denmark before entering the Dutch market as net metering is phased out.
Designed for seasonal storage
The residential storage market is currently dominated by lithium-ion batteries, which are highly efficient for short-duration electricity storage. However, they are not designed to store energy economically across seasons.
Photoncycle’s solid-state hydrogen system targets storage capacity costs significantly lower than conventional battery systems designed for long-duration storage, making it suited for summer-to-winter energy shifting.
While electrical round-trip efficiency is lower than short-duration batteries, Photoncycle integrates heat recovery into the system. When paired with a heat pump, recovered thermal energy increases the total usable energy delivered to the household, improving overall system performance in heating-dominated climates such as the Netherlands.
Subscription model to lower upfront costs
Photoncycle intends to offer its system under a subscription-based model in which the seasonal storage unit is installed at the customer’s property and operated as part of an integrated energy solution. The model can incorporate existing solar panels or include new installations, and covers maintenance, system operation and access to energy trading markets. The aim is to lower upfront investment while providing households with greater long-term price predictability in a post-net-metering environment.
Around a significant share of Dutch homes still rely on natural gas for heating, leaving households exposed to winter fuel price volatility. By storing summer solar energy for winter heating and electricity use, seasonal storage could reduce reliance on gas consumption during colder months.
Bjørn Brandtzæg, founder and chief executive of Photoncycle, said:
“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.”
Tomosaku Sohara, General partner at NordicNinja, said:
“From our perspective of bridging Japanese capital and European startup expertise, we strongly believe energy sovereignty must be strengthened across both Europe and Asia. Photoncycle combines deep technical innovation with a clear, scalable path to global deployment. Long-duration energy storage is critical to building resilient, reliable clean energy systems in Europe, Japan and beyond. We’re excited to help introduce the team to global opportunities, building on our long experience in the energy sector.”
The Series A funding will be used to scale manufacturing and support early commercial deployment in Denmark, followed by entry into the Netherlands as regulatory changes reshape the residential solar market.
About Photoncycle
Photoncycle develops hydrogen energy storage systems that enable households and businesses to store summer solar power for winter use. The company's patented technology transforms surplus renewable energy into solid-state hydrogen stored underground, releasing it as clean heat and power when needed. Founded in Norway and backed by experienced European investors, Photoncycle is building the distributed storage infrastructure for Europe's renewable energy future.
About NordicNinja
NordicNinja VC, established in 2019, is the largest Japan-backed venture capital fund in Europe. Focused on deeptech, climatetech and digital society, the fund specializes in scaling startups from Northern Europe, providing investments at Seed to Series A/B stages. The current portfolio covers over 30 companies, including Bolt and Einride. The fund’s speciality is the combination of a Japanese-European team of experienced founders, engineers, and operators turned investors, and access to a global network of Japanese enterprises.
About Voima Ventures
Voima Ventures is a Nordic venture capital firm investing in science-based and deep tech startups across the Nordics and Baltics. Founded in 2019, Voima supports early-stage companies emerging from university labs and research institutes. With its recently launched €107 million Fund III, Voima Ventures aims to back 25–30 high-impact startups that combine strong financial potential with transformative societal or environmental outcomes. Investment focus areas include life sciences, sustainable energy, quantum computing, advanced AI, and next-gen materials.
