Technology spotlight: Ideas from the past that will drive the transition

Mine-shafts. Bricks. 100-year-old sail designs. The climate crisis has led technicians and entrepreneurs to fundamentally rethink carbon intensive industrial processes, often garnering inspiration from technologies of the past. Here are three companies at various stages of commercialisation combining old ideas with fresh thinking (and capital) to reduce dependence on fossil fuels.

Norsepower

Eleven years ago a group of naval architects had an idea to reduce the environmental impact of the shipping industry, which as of 2018 accounted for nearly 3 percent of global greenhouse gas emissions, according to a study by the International Maritime Organisation. The idea was to revive a 100-year old innovation: a mechanical sail called the Flettner Rotor.

Originally developed in the 1920s, the Flettner Rotor is tall and cylindrical, and has more in common visually with a chimney than a conventional sail. It uses the same physical phenomenon that makes a spinning ball curve its way through the air: the Magnus effect. When air flows around the spinning object, it creates a sideways force: enough to make a ball move in flight, or a ship move through the water.

In the case of a rotor sail, the column is rotated – speed and direction determined by wind conditions – by electric motors, which provides forward thrust to the vessel. A rotor sail-driven ship crossed the Atlantic in 1925.

Based in Helsinki, Finland, Norsepower was founded in late 2012. It fitted its first prototype to a ship in late 2014 and by early 2015 had sufficient data to conduct some analysis. It showed fuel consumption had been reduced by 3 percent, says Norsepower CEO Tuomas Riski: “Not a huge number, but clear evidence that showed with one small rotor sail this works.” That ship – the Estraden – then had a second sail fitted and is still sailing, aided by those rotor sails today.

In the right conditions a ship can sail fully powered by rotor sails, but on average, says Riski, ships are using between 5 and 25 percent less fuel.

Norsepower is still in its pre-profit phase. “First we wanted to stablise the product and grow the market as fast as possible,” says Riski, “Now the market is growing and we are accelerating quite fast.” The company turned over around €8 million in 2023 and has an order book of more than €20 million, says Riski. He is speaking to me from China, where the company is building “the first ever mechanical sail factory in the world”, he says. “We are targeting a turnover of €100 million with one factory alone. Now we see that we could make the company profitable within two years, providing the market grows as it does today, which we have a lot of faith in.”

The company’s most recent funding round was a Series C in March 2023. French asset manager Mirova led the €28 million round from its Mirova Environment Acceleration Capital fund. Climate Investment, an existing investor, participated, as did other existing investors The Finnish Climate Fund (Ilmastorahasto), Nefco – The Nordic Green Bank, Tesi and Power Fund III.

Mechanical sails will be a feature of shipping through the energy transition and beyond, says Riski: “Long-haul shipping will always need fuel to run these ships; carbon neutral fuels like hydrogen will be many times more expensive than today’s fuels. In all visible future scenarios, you need to minimise the need for fuel; having mechanical sails on board is an elegant way to make it happen.”

Gravitricity

“Bluntly, it’s bloody difficult,” says Martin Wright, one of the co-founders of Gravitricity, on the task of storing energy for the long-term. Difficult as it may be, it is a task that needs tackling in a world in which we rely increasingly on renewable energy generation; energy produced during periods of sun and high wind (and low usage) needs to be stored for periods of cloud and low wind (and high usage).

Wright and his business partner Peter Fraenkel had previously set up Marine Current Turbines, a tidal stream energy business, and sold it to Siemens. In 2011, they were considering what problem to tackle next and decided that grid scale energy storage was a gap that would need plugging.

“It had to have the characteristics more of pump storage, than of batteries, which have a limited number of cycles,” Wright tells New Private Markets. “Peter said: ‘I used to work in mining, why don’t we chuck some heavy weights down disused mineshafts?'”

Using gravity to store energy was not a new concept; it is typically used in hydroelectricity, where water is pumped to higher ground and then released to drive turbines when needed. But these systems require favourable topography (ie mountains). Using disused mineshafts presents an opportunity to extend the life of pre-existing infrastructure, reuse the grid connection associated with the mine, and “make them into economic assets”, says Wright.

The idea relies on proven technology and “supply chains are familiar with the sort of technology we are using”. It is fast to activate – able to go to full power in under a second, says Wright – and the company is aiming to hit a “sweet spot” of four hours of output, because that’s when you start to negate the need for peaking plants.

Since inception Gravitricity has added hydrogen storage to its product mix; using the physical qualities of underground shafts to store pressurised fuel gas on a large scale.

The company has successfully developed a concept demonstrator for the gravity energy store. When NPM speaks to Wright in March 2024, the company is ramping up to raise fresh capital – around €42 million, he says – to finance, among other things, the development of commercial demonstrators for both the gravity and hydrogen products.

Plans are in place to build a gravity energy storage facility at a 1440 foot-deep disused zinc and copper mine in Finland. Mine sites in Germany, the Czech Republic and most recently Slovenia are engaging with Gravitricity about projects. In total Wright counts 79 project opportunities across both the gravity and hydrogen products globally. “There is no question that the market is there; we just have to have a really disciplined approach to exploiting that and to make sure we have the right parnters to deliver cost effectively.”

Rondo

“Bricks like this are going to cut 15 percent of world CO2,” says John O’Donnell, CEO and co-founder of Rondo, speaking to a TED talk audience in July 2023. Next to him is a grey block, about the size of a domestic washing machine. The block’s surface is interspersed with hollow sections, giving it the look of an out-sized children’s building block.

The brick is capable of being heated to over 1,000 degrees centigrade and running at that temperature for a lifespan of over 50 years, O’Donnell tells the audience. When situated in its container alongside identical bricks (between 1,000 and 12,000 bricks depending on the size of the unit), and heated by iron wire filament (as found in both industrial furnaces and in toasters on kitchen countertops around the world), the bricks becomes an industrial boiler that can store renewably generated energy and “run all day, all night on the wind and the sun.”

“When it’s red hot, a brick stores as much energy per pound as a lithium ion battery,” O’Donnell says, “It costs 10 times less and lasts 10 times longer.”

Rondo’s heat batteries are designed to cover the ongoing needs for industrial heat or power in a world where renewable energy is intermittent. “Heavy industry needs heat all the time,” O’Donnell says.

Like so many good ideas, using bricks to store energy is an old one. Steel mills have been using bricks within blast furnaces for 200 years. The raw materials are readily accessible too; “Brick is basically made from dirt, and dirt is available at scale,” he says.

Rondo was co-founded by serial entrepreneurs O’Donnell and Pete von Behrens, the company’s chief technology officer. The company completed a $25 million Series A funding round at the end of 2021, led by Breakthrough Energy and Energy Impact Partners, and including corporate partners Titan Cement Group and SCG, cement businesses based in Greece and Thailand respectively. The company subsequently brought in $60 million in follow-on investment from strategic investors Microsoft, Rio Tinto, SABIC, Aramco Ventures, and SEEIT.

The company is currently in conversations with investors around the next financing round, likely to happen mid-year 2024 seeking raise “well over $100 million”, O’Donnell tells NPM in the same week in March that drinks giant Diageo – in partnership with Rondo – has been selected by the US Department of Energy to receive up to $75 million to electrify three of its US production sites. The installation of Rondo heat batteries at the sites will provide “low-cost, zero-carbon heat and power, and eliminate reliance on natural gas for boilers used in heating processes”, the announcement states.

Earlier in the month, Rondo had announced a partnership with European energy business EDP to co-locate 500MW of distributed generation assets with 2GWh of Rondo heat batteries to provide EDP’s commercial and industrial customers with “a complete zero-carbon heat & electricity solution.”

“Technology like this is simple; it’s boring,” O’Donnell says in his TED talk. “But it can go to scale fast… New and boring is a strange combination, but it is an excellent recipe for going fast.”