Amsterdam-based energy storage startup Moonwatt has secured €8 million in funding to advance its sodium-ion battery technology, aiming to transform solar power storage. The round was co-led by daphni and LEA Partners, with participation from Founders Future, AFI Ventures, Kima Ventures, strategic business angels, and key customers.
With this investment, Moonwatt plans to accelerate the development and deployment of its hardware and software solutions, expand its team, and contribute to a more sustainable and resilient global energy system.
CEO and Co-founder Zukui Hu emphasized the company’s innovative approach, stating that they designed their battery storage system from the ground up, without relying on legacy technology. The goal was to create a storage solution that is not only more affordable but also safer and more reliable, ensuring scalability without material scarcity concerns.
The founders—Zukui Hu, CTO Guillaume Mancini, and CCO Valentin Rota—bring over a decade of experience in the renewable energy sector. They met while working at Tesla Energy, leveraging their expertise in storage, solar, wind, and power infrastructure to develop what they call the world’s first energy storage solution designed specifically for solar power.
According to Moonwatt, solar energy has expanded faster than any other power source in history, with global capacity expected to increase tenfold by 2030. However, its biggest challenge remains intermittency. While solar provides an affordable and abundant source of energy, it cannot supply power around the clock. During the day, solar farms generate excess electricity when demand is low, while energy supply struggles to meet demand at night.
This imbalance leads to grid congestion, price volatility, and project backlogs. Currently, over 3,000 GW of renewable energy projects are stalled due to grid bottlenecks, while surplus energy often forces plant operators to shut down or sell power at a loss.
Paul Bazin, Partner at daphni, highlighted the importance of energy storage in solving this challenge, stating that the rapid growth of renewables has outpaced expectations but now requires more efficient storage solutions to continue scaling. Moonwatt aims to fill this gap with a technology specifically tailored to solar energy storage.
The current market is dominated by lithium-based batteries, which were originally developed for electric vehicles and later adapted for energy storage. These batteries rely on expensive and scarce raw materials, making large-scale deployment costly and unsustainable. Moonwatt believes that sodium-ion technology presents the most viable alternative.
By focusing on sodium-ion batteries, Moonwatt is addressing the core challenges of solar storage. Sodium is 1,000 times more abundant than lithium, costs significantly less, and offers improved safety for stationary storage applications. The company’s battery systems are designed to seamlessly integrate with solar plants, boosting their capacity factor from the typical 15-20% range to as much as 80%.
Moritz Pagel, Investor at LEA Partners, sees Moonwatt’s sodium-ion approach as a game-changer, making 24/7 renewable power economically viable and unlocking new value for energy operators and consumers. He also praised the team’s expertise and execution capabilities, reinforcing their potential to lead this market shift.
Rather than retrofitting existing technologies, Moonwatt has developed a fully optimized energy storage solution from the ground up. This approach ensures that its battery systems are tailored to address the unique challenges of solar power, including price fluctuations, grid congestion, and scalability.
By colocating its storage systems with solar farms, Moonwatt aims to minimize reliance on expensive grid upgrades while stabilizing energy prices and reducing congestion. The company’s broader vision is to create an energy ecosystem where solar power can become the dominant electricity source worldwide.
This latest funding round positions Moonwatt to accelerate its mission, bringing more scalable, cost-effective, and sustainable energy storage to the market. As the global shift to renewables continues, solving the storage bottleneck will be critical in unlocking the full potential of solar energy.
