- Photoncycle raises €15M to move from full-scale pilot to commercial rollout of seasonal energy storage in Denmark and the Netherlands
- Solution provides households with lower and more predictable energy bills, energy independence, and self-produced renewable energy on a subscription basis.
- Equivalent to seasonal storage for roughly 140,000 homes – the First phase of planned 1.4 TWh annual manufacturing energy storage capacity expansion will go live in 2027
Oslo, March 4th, 2026: Photoncycle – Norwegian energy storage scale-up Photoncycle has raised €15M in Series A funding as it seeks to tackle one of Europe’s most persistent renewable energy challenges: enabling households to store surplus summer solar power for winter heating and electricity.
The round was led by NordicNinja and Voima Ventures, Nordic’s leading deep-tech and energy transition investors, with participation from existing investors Lifeline Ventures, Eviny Ventures, Luminar Ventures, Momentum, and Startuplab. The funds will support commercial rollout in Denmark and the Netherlands and finance the first phase of an industrialisation plan that includes a proposed 1.4 terawatt-hour annual manufacturing facility.
The investment comes as Europe continues to grapple with the structural vulnerabilities exposed by the 2022 energy crisis. The EU imported €396bn of fossil fuels in 2025, around €880 per citizen, underscoring the bloc’s continued dependence on external supply even as renewable generation expands. Winter exposure remains particularly acute: space heating accounts for 62.5 per cent of household energy use, while natural gas remains a significant component of residential consumption, leaving households sensitive to seasonal price swings in global gas markets.
At full industrial scale, Photoncycle’s proposed 1.4 TWh manufacturing facility would represent storage capacity equivalent to roughly 140,000 homes each storing 10,000 kWh of seasonal energy. Photoncycle’s distributed, household-level seasonal storage is designed to reduce the volume of imported gas required to meet winter heating and electricity demand, and consequently reduce Europe’s reliance on importing fossil fuels in the winter.
Subscription model to lower and more predictable energy bills
The company intends to offer the system under a subscription model that includes rooftop solar panels, 10,000 kWh of seasonal energy storage, and full servicing. Photoncycle’s system increases household energy independence and improves cost predictability for heating and electricity. By reducing reliance on grid electricity during high-price periods and lowering exposure to grid tariffs, the system is designed to reduce total energy costs by 30 percent on average. Photoncycle has already seen strong interest from households seeking alternatives to gas-based heating. In Denmark, where Photoncycle has a rapidly growing list of pre-orders, energy prices are among the highest in Europe and 300,000 homes still depend on gas-based heating systems that are set to be phased out by 2035.
Bjørn Brandtzæg, founder and chief executive of Photoncycle, said the company was focused on moving seasonal energy resilience closer to consumers. “Europe is beginning to solve short-duration storage,” he said. “The remaining gap is seasonal. If households can store cheap solar powered summer energy for winter use, they reduce exposure to imported fuel and price volatility as well as to increasing grid costs for consumers.”
Tomosaku Sohara, Co-Founder and 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.”
Inka Mero, Founder and Managing Partner at Voima Ventures, said: “As the share of renewable energy increases, structural price volatility in electricity markets is rising. Seasonal storage is therefore not a niche solution, but a systemic necessity. Photoncycle addresses this imbalance by enabling households to store energy across seasons and reduce their dependence on imported fossil fuels. This is a radically important building block for a resilient and sovereign European energy system.”
The Series A funding will now be used to scale manufacturing and early commercial deployment in Denmark initially, followed by Europe’s other large markets including the Netherlands. Beyond Europe, there are opportunities to scale Photoncycle’s breakthrough technology in Asia, including Japan, and in the US.
