Deep Tech Brief #14

Welcome to this week's issue of Deep Tech Brief.

Every Saturday, we break down deep tech companies building genuinely hard things, in plain language. No jargon, no hype.

Three companies this week: whisky made with stored wind in Scotland, animal feed grown on olive waste in Andalusia, and magnets mined from old electronics in Milan.

Let’s dive in.

On a windy night, Britain regularly pays wind farms to switch off. The grid cannot always absorb the power when it arrives, so it is thrown away, and someone pays for that. By Exergy3's figures, balancing the UK grid cost £2.7 billion last year.

Meanwhile, factories burn gas for heat. Distilling, brewing, food processing and chemicals need steam and high temperatures around the clock, which is why industrial heat is so hard to clean up. Wind is cheap but unreliable. A boiler needs to run on Tuesday morning whether or not it was windy on Monday night.

Exergy3, spun out of the University of Edinburgh, sits in the middle. Its system soaks up surplus electricity when it is cheap and plentiful and stores it as heat, at temperatures of up to 1,200 degrees, then releases it steadily as the site needs it. The whole unit fits inside a shipping container, so it is delivered and installed on site rather than built from scratch. By the company's own figures, one container can hold up to 36 megawatt hours of heat.

The technology was invented by Dr Adam Robinson at Edinburgh's School of Engineering; his former teaching assistant, Dr Markus Rondé, now runs the company.

Thermal batteries are a busy corner of climate hardware, with names like Rondo Energy in California and Kraftblock in Germany. What stands out about Exergy3 is where it has already proven itself. Its trial ran at Annandale Distillery in south-west Scotland, backed by £3.6 million of UK government funding, and the distillery has now adopted the system to make one of the world's first low-carbon whiskies.

Where they are: a £10 million seed round in April, led by Axeleo Capital with Bayern Kapital and Kibo Invest, alongside existing backers Scottish Enterprise, Zero Carbon Capital and the university's own fund. The money moves it from pilot to commercial deployments.

Worth watching, because a working installation at a paying industrial customer beats any lab result, and it links two problems usually solved separately. The milestone ahead is repetition: turning one distillery into a fleet of sites across heavier industries that need the same thing.

Learn more: exergy3.com

For every litre of olive oil, several kilograms of thick, wet paste are left behind: crushed skins, pulp and stones. Andalusia alone produces around 4.8 million tonnes a year, by the company's figures, and much of it is dried and burned.

Yet Europe imports most of the protein it feeds its farm animals, largely soy from the Americas. So one of the continent's biggest farming regions sits on a mountain of organic material while its livestock and fish farms depend on protein shipped across an ocean.

InsectBiotech, founded in 2022 and based in Andalusia, puts black soldier fly larvae in between. The larvae eat the olive residue and, in about two weeks, turn it into protein meal for fish, poultry, pigs and pets, oil for biodiesel, and fertiliser for vineyards. The hard part was the feed. Everyone told the founders olive pomace could not be used, so they developed a low-cost pre-treatment with the University of Granada that makes it digestible, now patented.

The insect protein industry has had a difficult few years, and the founders are candid about what the first wave struggled with: expensive feed, high energy bills and costly, heavily automated factories. InsectBiotech is designed around all three. Its feed is a waste stream bought on long-term contracts, which the company says costs as little as a quarter of grain-based feed. Its plants run largely on Andalusian sunshine, which the larvae like, and it scales in modest, modular steps. As co-founder Tobias Webb puts it, the goal is to compete on cost, not on sustainability alone.

Where they are: founded by chief executive Ignacio Gavilán, Webb and chief operating officer Ben Brown. A €7.2 million round in July, led by Arcano Partners through an Andalusian innovation fund, with US investors making up the rest. The money builds the first commercial plant, processing up to 7,500 tonnes of agricultural residue a year and due to open in the third quarter of 2027. The company says it has close to a dozen letters of intent from buyers.

Worth watching, because it starts from the economics rather than the biology, and its feedstock is abundant, local and cheap. The milestone ahead is the 2027 plant: showing a consistent product at commercial volume, which is what the big feed buyers have told the company they want to see.

Learn more: insectbiotech.eu

Every electric car motor, wind turbine and hard drive depends on a small, very strong magnet made from neodymium, iron and boron. They are among the most important parts of the energy transition, and almost none are made in Europe.

China produces around 86% of the world's rare earth minerals, according to the European Parliament, and the EU gets all of its heavy rare earths from there. Meanwhile, those same magnets sit in Europe's drawers and scrapyards, inside old hard drives, motors and appliances, and less than 1% of the rare earths the EU uses are recycled. Brussels now wants recycling to cover a quarter of demand for critical raw materials by 2030.

RarEarth, founded in 2023 and based in Milan, is building the piece that turns that scrap back into magnets. Its patented process pulls end-of-life magnets out of electronic waste, breaks them down with a low-temperature treatment, and refines the recovered alloy back into new neodymium magnets. The company says it recovers close to all of the magnetic material, and that tests at the Politecnico di Torino's magnetics lab showed the recycled magnets performing on a par with new ones.

That last point is what matters commercially. Recycled material is only useful to a motor maker if it behaves exactly like the original. RarEarth also says its magnets carry around 76% lower emissions than new production, and the whole chain stays in Europe.

Demand is moving fast: by the company's figures, European demand for these magnets should roughly triple by 2030, to about 36,000 tonnes a year.

Where they are: led by co-founder and chief executive Enrico Pizzi, and incubated at I3P, the Politecnico di Torino's incubator. A €2.6 million round in July 2025, led by Primo Capital and MITO Tech Ventures, was followed in June by a €2.5 million European Innovation Council grant, with up to €6 million more in equity possible. It was the only Italian company in that EIC round, and the grant funds its first production plant.

Worth watching, because Europe's policy, its industry and its scrap heaps all point the same way, and matching new-magnet performance is the hardest part to get right. The milestone ahead is the first plant: turning lab results into a steady, affordable supply manufacturers can design into their motors.

Learn more: rarearth.it

Know a deep tech company we should break down next? Hit reply and tell us. The best editions come from real tips.

See you next Saturday.