Billionaires' fund backs Malta molten moonshot

‍This is an analysis piece written by our Editor- in-Chief Richard Heap for Energy Storage Report

I love the week before Christmas. Yes, it’s almost mid-January, so no doubt some of you are furiously grinding your teeth at any mention of ‘the C word’. All I can say is watch out for next month’s romance-related puns.

There are a few reasons why the week before Christmas is great. First, the office is quieter than normal. Second, I don’t feel as guilty about grazing on office snacks. And third, it’s when we find out about the deals that people were madly rushing to complete before year end.

In the storage sector, one that stood out to us was the $26m investment in Boston-based start-up Malta by Breakthrough Energy Ventures, which is the fund set up in 2015 to invest in groundbreaking energy technologies and is backed by well-known names such as Jeff Bezos, Michael Bloomberg, Richard Branson, Bill Gates, Jack Ma and Masayoshi Son. The funds helped turn Malta from an idea into a standalone company, in a Series A round of investment that was also backed by Alfa Laval and China’s Concord New Energy.

Malta started life in the research firm X – The Moonshot Factory, which is owned by Google’s parent company and was formerly known as Google X. Malta is focused on energy storage systems that use excess electricity to heat molten salts and cool low-temperature anti-freeze, creating a large difference between the temperatures. This differential can then be converted into electricity when energy is required.

Malta explained more about the deal in this blog post on 19th December, where the company’s chief executive Ramya Swaminathan said the capital investment would enable Malta to further develop its system.

She said its system was the “first-of-a-kind” and would “facilitate further expansion of renewable energy while improving grid stability and resilience across the globe”. We wanted to take a quick look at the Malta system and its growth plans following this transaction.

Molten salt storage systems

Its system is based on the principles of thermodynamics, which the Massachusetts Institute of Technology handily explains in this article about thermoelectric materials.

When a thermoelectric material is exposed to a temperature gradient — for example, one end is heated, while the other is cooled — electrons in that material start to flow from the hot end to the cold end, generating an electric current. The larger the temperature difference, the more electric current is produced, and the more power is generated.

That is, in essence, how Malta’s system works. It starts by receiving electricity from either renewable or fossil-fuel-based sources, and uses this to heat molten salts and cool antifreeze liquid. These can sit in a charged state for days or a week. This can be converted into electricity when needed by feeding the temperature differential into a heat engine, and then goes to the grid.

We spoke to Adrienne Little, heat exchanger technical lead at Malta, who said that the firm was benefiting from research already done in the renewables sector about the use of molten salts in the concentrated solar power sector: “We like to think we’re standing on the shoulders of giants, and can learn from their experiences.”

Little said one big benefit of the technology is it could fit at various points in the grid, whether it is paired with a wind farm, part of a microgrid, or sitting at a difficult point in the transmission system: “In a sense, this is a puzzle piece that can fit anywhere,” she said

That’s the theory. Malta is now set to work with industrial partners to turn its detailed designs into pilot systems, but the company said it is too early to share more details about specific pilot projects. It added that its system’s ability to store electricity for days or longer had the potential to make renewable energy more productive and cost-effective. As Raj Apte, science advisor at X put it, this technology “gives us a shot at storing all the renewable energy we create cheaply and reliably”.

Breakthrough’s billionaire backers

This is why Breakthrough is keen to invest. The fund was set up in 2015 to invest in start-ups working on potentially ground-breaking technologies to support transition to low-carbon sources in the global energy system including storage, microgrids and geothermal. Other recent storage deals include QuantumScape.

In our view it can only be good to have investors like Breakthrough, and its big-name backers, taking an interest in storage. Plenty of rival venture capitalists have reportedly been wary about the sector, given the tough competition between the different technologies and stories of investors in storage who’ve previously come unstuck.

Breakthrough’s head of investing Carmichael Roberts said that solving intermittency of renewables is “a critical part of delivering inexpensive and renewable energy”.

He said that Malta offered a different approach from conventional batteries, in a way that uses “existing components and inexpensive resources” that make it cost-effective to scale. He also said the other partners in the investor syndicate – Alfa Laval and Concord – were part of the appeal for Breakthrough getting involved.

Liu Shunxing, chairman at Singaporean conglomerate Concord, which highlights its strong links to the oil sector on its website, said he saw wide applications for Malta’s system: “[It] can be widely applied to various energy storage markets such as grid peak load shifting, auxiliary services, distributed energy resources, business and industrial parks, and more, with considerable development potential,” he said.

Finally, Alfa Laval brings experience with heat transfer tech that should help Malta, according to the president of its energy division, Susanne Pahlen Aklundh.

Malta may have graduated from being a ‘moonshot’, but there’s plenty of space to cover before it’s mainstream.