Moonwatt raises €8 million to power the sodium-ion battery revolution for 24/7 renewable energy
Moonwatt raises €8 million to power the sodium-ion battery revolution for 24/7 renewable energy
● Moonwatt is building the first dedicated sodium-ion energy storage system for solar to make clean power available 24/7 and solve the $400bn sector’s most critical challenges
● Founded by energy innovators from Tesla, EDF, Siemens, Scatec and Freyr Battery, Moonwatt’s system has been built to be globally scalable and cost-competitive from day one
● The funding will help accelerate development of its novel solar+storage hardware and software solutions and drive the shift toward a cleaner, more resilient ecosystem
Amsterdam, February Xth, 2025: Moonwatt – the energy storage startup founded by seasoned professionals with a track record at global leaders like Tesla, EDF, Siemens, Scatec, and Freyr Battery – has raised €8 million to unlock the true, 24/7 power of solar with its disruptive sodium-ion battery system. Co-led by daphni and LEA Partners, Founders Future, AFI Ventures (by Ventech) and Kima Ventures also participated alongside strategic business angels and customers. The funding will be used to accelerate the development and deployment of Moonwatt’s hardware and software technology, expand the team and drive the shift toward a cleaner, more resilient global energy ecosystem.
Overcoming critical renewable challenges
After more than a decade in energy innovation, co-founders CEO Zukui Hu, CTO Guillaume Mancini, and CCO Valentin Rota launched Moonwatt on the belief that clean energy only succeeds if the systems that power it are scalable, sustainable and competitive. To achieve this, Moonwatt is developing the world’s first energy storage solution specifically for solar power.
Solar has scaled faster than any energy source in history, with capacity set to increase tenfold by 2030. But despite being affordable and abundant, it isn’t dispatchable 24/7. Power floods the grid during daylight hours when demand (and prices) are low, but when the sun sets, the infrastructure isn’t in place to keep it flowing. This intermittency causes congestion and price cannibalisation; over 3,000 GW of renewable projects are currently stuck in grid backlogs while wholesale prices regularly plunge below zero due to the excess, forcing plant owners to shut down production or sell at a loss.
Storage holds the key but remains the sector’s biggest bottleneck. Today’s lithium-based batteries haven’t been specifically built for solar or optimised for very large-scale storage – they rely on scarce, costly materials, and are built on adapted legacy tech designed for EVs. The only way to solve this is to make solar storage more competitive, which relies on finding a sustainable, scalable, and cost-effective alternative. It’s a challenge that’s created a $400+ billion market opportunity, and it’s an opportunity Moonwatt is uniquely positioned to lead.
Redefining solar: a truly optimised system
Instead of retrofitting legacy technology or settling for a one-size-fits-all approach, Moonwatt’s battery energy storage system is built from the ground up to not only meet solar’s specific intermittency, price and congestion challenges but to work anywhere in the world from day one.
Moonwatt’s energy storage systems ditches lithium-ion for sodium-ion – a 1000x more abundant, a third cheaper and safer alternative which is better suited to building scalable, sustainable, and cost-competitive stationary storage. When deployed, the systems will co-locate storage with solar plants to increase their capacity factor from 15-20% to up to 80% to reduce the need for costly grid upgrades, all while cutting congestion, stabilising prices and making round-the-clock clean energy a reality. This is part of Moonwatt’s mission to build a truly-optimised solar system to unlock solar’s potential and make it the dominant power source worldwide. At full potential, this approach has the power to help the industry abate up to 14 GtCO2 per year by 2050.
Zukui Hu, CEO and Co-Founder of Moonwatt, said: “We started our product design from a blank sheet of paper, freeing ourselves from legacy features inherited from other segments of the battery industry, with the goal of designing a system from scratch that is fundamentally cheaper, safer and more reliable. Our vision is a product that can be deployed anywhere, and that can be scaled up multiple orders of magnitude without facing raw materials scarcity.”
Paul Bazin, Partner at daphni, said: “Renewable power growth has exceeded all expectations, but we’re approaching a tipping point where it won’t be able to scale further without better energy storage. Created by industry veterans, Moonwatt is solving this with a differentiated storage product built specifically for solar – this is the breakthrough the industry has been missing.”
Moritz Pagel, Investor at LEA Partners, said: “By focusing on sodium-ion, Moonwatt represents a paradigm shift, finally making 24/7 renewable power truly competitive and unlocking massive value for operators and consumers. We’ve been amazed by the complementary skillset and execution power of the team and are excited to back Moonwatt.”
Marc Menasé, Founding Partner at Founders Future, said: "At the heart of every game-changing innovation is an exceptional team. Moonwatt combines world-class expertise with relentless execution to tackle one of the biggest challenges in renewable energy: scalable and cost-efficient storage. Their visionary approach and breakthrough technology have the potential to transform how we store and distribute clean energy, and we’re proud to support them on this journey."
With a focus on innovation, technical excellence, and global impact, Moonwatt offers the chance to shape transformative energy storage solutions that will redefine solar integration. Moonwatt is actively hiring: engineers, scientists, and business leaders passionate about sustainable technology are encouraged to join this fast-growing organisation.
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About Moonwatt:
Founded in 2024 and headquartered in Amsterdam, Moonwatt is developing the next generation of highly competitive Energy Storage Systems utilising advanced sodium-ion battery technology. The company’s development work encompasses both the hardware and software components of its storage technology. Moonwatt’s products are uniquely dedicated to coupling with solar power plants. The company’s mission is to make affordable solar power dispatchable anytime, anywhere.
Moonwatt was co-founded by Zukui Hu, Guillaume Mancini and Valentin Rota, who met during their time at Tesla Energy nine years ago and have been working together since then as a complementary team. With a diverse set of skills and experiences in the storage, solar, wind and power sectors, they have developed a deep renewable power expertise as well as a comprehensive industry network. Since its inception, Moonwatt has attracted a talented team of professionals from the global energy sector. Visit www.moonwatt.com to learn more.
About daphni:
Founded in 2015, daphni is a European leading venture capital firm. daphni’s mission is to manage the planet transition and to empower founders to build a socially and environmentally sustainable future by leveraging new usage deep tech & disruptive innovations. With some 60 active investments including Back Market, Pasqual, H, Stockly, Geev, Swile, Kolet and Typology, the strategy of the funds managed by daphni is based on new tech and usages that can conquer global markets. As a mission-driven and B Corp certified company, daphni's mantra is Build da City. For. Good. daphni's value proposition to entrepreneurs and LPs is built around its community of more than 350 experts and its proprietary open innovation platform. Visit www.daphni.com to learn more.
About LEA Partners:
With over €2 billion in cumulative capital commitments, LEA Partners is an entrepreneurial-minded multi-stage venture capital and private equity firm investing in technology companies that are driving transformative change in their industries. Founded in 2002, LEA Partners was part of the investment in more than 100 companies. With a 35 people strong team based in Karlsruhe, one of Europe's largest technology clusters, its mission is to fund and support ambitious founders and executives by leveraging them with practical, hands-on growth expertise to achieve market leadership. Visit www.leapartners.de to learn more.
About Founders Future:
Founders Future is an early-stage investment group dedicated to Tech. Founded in 2018 by serial entrepreneur Marc Menasé and backed by a collective of entrepreneurs, leading European families, and institutional investors, the firm sees entrepreneurship as the most powerful driver to tackle the key challenges of tomorrow. Supporting ambitious founders at every stage of their journey, Founders Future combines capital, a strategic network, and operational expertise to help them scale and transform industries. With over 100 companies and 300 founders in its portfolio, the investment group ranks among Europe’s most active early-stage funds, backing tech champions like Waterdrop, Conduktor, Lydia, Alma, Taster, Neat, Veesion. As a B Corp-certified firm, Founders Future aligns performance with impact, leveraging a dynamic community of experts and industry leaders to empower entrepreneurs and LPs. Visit www.foundersfuture.com to learn more.
About AFI Ventures by Ventech:
AFI Ventures is a seed & pre-seed fund supporting impact startups focused on environmental and social issues. Managed by Ventech, categorized Article 9 and powered with €31.5 million, AFI Ventures is committed to supporting the emergence and the scaling of entrepreneurs at the intersection of "for profit" and "for good”. As Europe’s day one impact launchpad, AFI Ventures supports founders, in France and in Europe, to develop fairer and more sustainable solutions for all sectors of the economy. Visit www.allianceforimpact.com/ventures/ to learn more.