Breakthrough Energy Ventures Invests in Liquid Tin Thermal Battery Innovation

In a move that underlines the growing momentum in innovative clean energy technologies, Breakthrough Energy Ventures—the energy investment firm founded by Bill Gates—has placed its support behind a novel thermal storage startup, Fourth Power. This recent investment champions the creation of renewable power backup solutions essential for a more resilient and sustainable energy grid.

Fourth Power harnesses the power of liquid tin to revolutionize the way energy is stored. The company has developed a thermal battery that utilizes heat conversion to store energy, a process that entails transferring heat to carbon blocks at fiercely high temperatures. Once stored, this energy can be transformed back into electricity through advanced thermophotovoltaic cells when needed, addressing a primary concern in the renewable energy sector: the intermittent nature of power sources like solar and wind.

With the distinguished venture capital firm DCVC leading the charge in the Series A funding round, Fourth Power raked in $19 million, alongside contributions from other notable investors such as the Black Venture Capital Consortium and Gates' Breakthrough Energy Ventures. This influx of capital will allow Fourth Power to realize its vision of building a prototype facility in Boston. This facility, projected for completion in 2026, aims to store a significant 1 megawatt-hour of energy, roughly enough to power a thousand homes.

Coupled with its strategic location, Fourth Power's liquid tin thermal battery is a beacon of hope for an industry grappling with the limitations of current storage technologies, like lithium-ion batteries. Not only does Fourth Power’s solution have the potential to outclass lithium-ion batteries in terms of longevity, but Carmichael Roberts, co-leader of Breakthrough's investment committee, also speculates that their technology could be up to ten times more cost-effective.

Understanding the necessity for a sustainable and reliable energy grid, Breakthrough Energy Ventures has widened its portfolio within the thermal energy storage space. Previous investments have been in like-minded companies such as Antora Energy, Malta, and Rondo. The goal is simple yet profound: to aid promising firms in scaling their innovations for the utility-scale renewable grid at a low cost.

Renewable energy’s rise to prominence on the power grid poses challenges and opportunities. Long-lasting storage technologies become imperative when solar and wind power sources are dormant. Reserving renewable energy as heat for extended periods is one of the promising avenues offering substantial storage capabilities. BloombergNEF analyst Stephanie Diaz concurs, noting the supplemental advantages of the thermal storage, which includes flexibility in location and energy density.

The burgeoning interest in thermal storage is mirrored in the recent surge of investment activity, with startups in this domain raising an eye-catching $96 million in a single quarter. Moreover, Breakthrough's investment strategy doesn't hinge solely on thermal-centric enterprises. It also embraces companies innovating in other long-duration power storage technologies with ventures in ESS and Form Energy, both of which rely on differing electrochemical processes.

Roberts stresses the importance Breakthrough Energy Ventures places on early-stage, transformative projects led by exceptionally skilful founders. By offering strategic support, these startups can potentially spearhead significant technological breakthroughs not just within thermal energy storage, but also in alternative approaches to sustainable power solutions.