As storage plays a key role in enabling green transitions, the push to decarbonize the economy through electrification and clean energy continues to generate momentum around battery technology. Renewables are cleaner energy sources compared to fossil fuel burning, but their output is not always consistent. In the case of the sun – its development has been rising significantly in recent years – when the sun stops shining with solar cells, power generation will stop.
One solution to regulating solar plant variability is to store energy when there is an excess (time during the day). In this way, stored power can be made available at other times, such as providing a period of higher demand. This is usually also the second half of days when there is little sunlight.
Moonwatt, a clean, high-tech startup founded in the Netherlands last September, is working on an optimized battery-based energy storage system, hosting in collaboration with solar power plants to manage this fluctuation. The team designed dedicated battery enclosure hardware, inverter power electronics, to connect to the grid, and designed the software needed to integrate and manage the storage system.
The startup says that their approach allows solar power plants to sell more solar energy (including when energy prices are more attractive), allowing them to reduce costs at the plant level, allowing them to increase revenues by allowing designs to reconcile some of their electrical infrastructure. Target solar plants produce at least several hundred kilowatts of energy. Basically, it's something other than the development of solar power generation in homes.
In particular, Moonwatt's system is built around sodium ion cells in batteries that store solar energy. This technology offers an attractive alternative to lithium ions as it relies on cheaper (and easier to source) raw materials to produce and helps to keep costs down.
Sodium-ion batteries can have size and weight challenges as they are less denser than lithium-ion cells, but can make certain uses challenging (such as mobility/EV where weight is an important consideration).
Get more juice from PV
The pitch to Moonwatt's solar power plant means that the energy storage system can increase the capacity factor by up to 80%. They suggest that plants that buy can double their internal rate of return (IRR).
“It's basically about allowing partners to double the return,” co-founder and chief commercial officer Valentin Rota tells TechCrunch. “So AAA [credit-rating] Country, I would say average PV [photovoltaic] The assets are around, but let's use a return of 8% to 12% – IRR -. Increases assets by approximately 20%. ”
The startup founding trio met with CEOs Zukui Hu and CTO Guillaume Mancini while working on Tesla's battery technology almost a decade ago. They have since worked with a variety of employers on a variety of projects, including gaining experience in small, off-grid solar storage.
“We started off with something called microgrids, so it's usually a small grid resistance generator,” says Rota. “But because the costs of batteries have dropped and the costs of storage have actually started to arrive in larger countries on larger grids, and are actually driven by the basic pace of the sun.”
The founder was also collaborating with battery maker Freyr (as it was rebranded as Ti Energy). And I think seeing the cost of moving in the right direction, Rota realized that the spark to set up a moonwatt named after his energetic play in “Moonshot” could apply battery hardware knowledge and battery technology to enhance the gains of solar storage.
“I realized that this application (solar storage) is the backbone of the Future World Power Grid, but there is no dedicated product yet,” he says. “That's what Moon Watt is about. It's to create the first solar-specific battery storage product.”
With the continued surge in the amount of solar energy produced globally, startup bets are that the industry will start looking for dedicated storage rather than creating “cookie cutter” products.
With each ROTA, Moonwatt's “big differentiator” includes the use of sodium ion battery technology. He offers better scalability, cost savings and carbon emissions than lithium ions.
Storage systems design uses distributed architectures (rather than centralized), making them easier to integrate as the plants conveyed. He also says the approach they are taking can increase efficiency and reduce the cost of power that can be dispatched to connect storage much closer to the peak output panel.
“With these three features, the comprehensive goal is to reduce the electricity costs of these dispatchable solar power plants,” he adds.
Seed funds to step on gas
This (just) month ago business and its prototype products are still too early, but Moonwatt has now shut down 8 million euros (approximately $8.3 million at its current exchange rate) to step out of gas and bring stocks to the market. We expect that we will be in a position to carry out our first commercial expansion in 2027.
Seed Round is co-led by Daphni and Lea Partners, with participation from Founders Future, AFI Ventures (Ventech) and Kima Ventures, along with strategic business angels and customers.
Daphni's partner Paul Bazin commented in a supportive statement, suggesting that Moonwatt's approach is a “breakthrough that the industry is missing.”
“Growth in renewable power exceeds all expectations, but we are approaching a turning point where we cannot shrink even further without better energy storage,” he said. “Moonwatt, created by industry veterans, solves this with a differentiated storage product built specifically for solar.”
“We really cultivate our ambition to become a gigawatt-hour player, a large player, because we want to make an impact,” Rota also says. “And scale comes at a cost, and in this industry, we know it's a final line-driven business, so we have to put a competitive cost.”
Rota says the decision to focus on solar energy is summarised in attractive economics and already extensive incorporation of this type of renewable energy.
“Solar is interesting because it costs every megawatt hour, which makes it very competitive and gives you more,” he notes. “But this also means that solar is a little more ubiquitous. It is already deployed in over 120 countries a year.”
Optimizing just for solar means that the focus can be fully on design choices aimed at ensuring plants can make the most of their assets, including when startups reduce the cost of connecting energy to the grid.
“How to look ahead and reduce [solar energy] Cost is to reduce the overall balance of plant costs. Therefore, the number of transformer cables and so on should be reduced. The way to do this is to combine solar and storage at low voltage levels, not at medium voltage levels.
“In doing so, they share the same electrical infrastructure and connect to the grid. And if we expand our view a little like at the national level, this is something we have to do to optimize grid capacity usage. Today, standalone solar plants only use about 20% of grid capacity, but adding storage behind the meter actually allows us to use this grid capacity more efficiently.”
The startup business on hand is also helping solar power plants switch from developers with tariff feed to becoming energy traders with flexible assets, he adds.