EIC Accelerator Winner Teraloop and the Grid Storage Race

Teraloop Oy, a Helsinki company registered in 2014, builds flywheels: carbon-fibre rings that store electricity as rotation and give it back within milliseconds. In the EIC SME Instrument Phase 2 round of 9 January 2019, the forerunner of today's EIC Accelerator, it was selected for Teraloop EES, a €3,465,625 project to demonstrate its flywheel "in an industrial pilot", with an EU contribution of €2,425,937.50, according to CORDIS and the European Commission's list of selected companies, which names Teraloop as the only beneficiary of the project. The grant was grant only, without equity.

Seven years later Teraloop is still operating and still loss-making. Its website lists one documented customer installation, a 100 kW flywheel at a dairy on the Azores island of Terceira, running since April 2024, and in July 2026 it announced a second island project with the Azores utility EDA, according to the company and its announcement. The Spanish grid equipment group Arteche bought into the company in September 2024. Revenue in the filed accounts is close to zero.

Where Teraloop Stands Now

The Finnish trade register shows Teraloop Oy as active, with its office at Ruosilantie 18 in Helsinki and its registered domicile in Espoo, according to Finder and Asiakastieto. Neither shows insolvency proceedings. Asiakastieto lists Antonio Capristo as chief executive, Angelo Prete as chairman and Enrico Paolo Maria Calabretta and Atte Heiskanen as board members. Neither of the 2018 leaders appears on today's team page: Ted Ridgway Watt was chief executive, with Philippe Pépin as chief operating officer, when the EU grant was announced in 2019, according to Silicon Canals and Scan Magazine; when he handed over could not be verified.

The company's news page shows steady activity: the Arteche deal in September 2024, a hire of a sales director in July 2025, a Business Finland research project with Aalto University on backup bearings and rotor sensors announced in December 2025, and the Corvo project in July 2026, according to Teraloop's own posts. Its team page names a chief executive, a CTO, a CFO, a sales director and a chief engineer.

The Technology: A Flywheel Without a Hub

A flywheel stores energy in a spinning mass, and the energy grows with the square of the speed. In a conventional rotor the central hub limits that speed, because it creates radial stress in the material. Teraloop's rotor is a carbon-fibre ring with no hub, levitated on magnetic bearings in a vacuum, which the company says lets almost all the fibre be wound in its strongest direction and gives "up to five times the storage capacity of a hubbed rotor", according to its technology page. CORDIS repeats the five-fold claim from the project summary. No independent test of that figure was found.

The selling point against batteries is speed and wear. Teraloop says its system delivers full power in under 10 milliseconds, holds it for up to 15 minutes and can be cycled without degradation for 25 years; Arteche's product page for the jointly sold system gives the same 10 millisecond figure. That puts the flywheel between supercapacitors, which deliver for seconds, and batteries, which deliver for hours. It is a power device, not bulk storage.

The shift in scale is visible in CORDIS. Teraloop's 2018 Phase 1 study, worth €50,000 from the EU, set out a roadmap whose second phase was "an industrial demonstrator of 10MW Teraloop" and whose third was to "commercialise 10MW Teraloop and develop 100MW Teraloop", according to CORDIS. By the end of the Phase 2 project the pitch had become a "companion technology to batteries, making them work better and last longer". Today's grid page cites a simulation study of the Azores islands of Corvo and Flores that modelled a 250 kW "PowerLoop 250" unit.

What the EIC Grant Promised, and What It Produced

The grant agreement was signed on 12 April 2019 and the project ran from 1 May 2019 to 31 October 2021, as planned. The final report, for May to October 2021, says Teraloop "completed a pilot device design, manufacture, assembly, test and evaluation" and was "now deploying a pilot system at a virtual power plant with Siemens and Sello Shopping Mall", a six-month pilot meant to show longer battery life and revenue from the frequency containment market. It added: "Teraloop expects to form commercial agreements with clients in 2022", according to the CORDIS report.

No published result of the Sello pilot was found, and no commercial agreement from 2022. The next customer installation Teraloop documents is the Terceira dairy, which the company links to IANOS, a separate Horizon 2020 project for island energy systems in which Teraloop received €143,500, according to CORDIS. The EU's Clean Energy for EU Islands site reported in February 2025 that a flywheel was among the completed installations on Terceira, without naming its maker. CORDIS gives no publications or patents for the EIC project.

1. Pilot flywheel designed, built and testedDeliveredFinal CORDIS report, 2021.
2. Industrial pilot with Siemens at SelloUnverifiedAnnounced as starting in 2021; no results published.
3. Commercial agreements in 2022Not achievedNone announced; first documented customer unit April 2024.
4. 10 MW industrial demonstrator (2018 roadmap)Not achievedLargest documented unit is 100 kW.
5. Project on timeDeliveredEnded 31 October 2021 as scheduled.

The Money Since the Grant

Teraloop's first outside backer was Yaskawa Electric, the Japanese drives and robotics maker, which invested in 2017, according to The Switch, a Yaskawa company; a 2018 Switch article on Yaskawa's start-up holdings lists "Teraloop Oy, a Finnish company for large-capacity storage of kinetic energy" (The Switch). The amount is not public.

On 6 September 2024 Arteche, based in Bilbao, announced a strategic investment through Arteche Ventures. It took a permanent board seat and exclusive distribution rights in the main countries of its power quality business, and said the flywheels would be sold as "Arteche powered by Teraloop" from early 2025, as stand-alone units or inside its capacitor banks, according to Arteche and Teraloop's own press release. Neither disclosed the size of the stake. Italy's Sky TG24 reported that Arteche joined the Italian shareholders Krill Energy and Kinextra and Yaskawa; the Italian holdings could not be confirmed in a second source. Sky TG24 also called Teraloop a University of Helsinki spin-off, while the company says it grew up in the innovation hub of Aalto University.

The accounts show a company still in development. Its operating loss was €363,000 in 2021, €1.10 million in 2022, €719,000 in 2023, €1.87 million in 2024 and €1.70 million in 2025, according to Asiakastieto and Finder, which agree to within €1,000. Finder puts the net loss at about €2.0 million in 2024 and €1.7 million in 2025. Staff rose from 11 in 2022 to 13 in 2023 and 15 in 2024. Asiakastieto gives an equity ratio of 76% for 2025, counting subordinated loans as debt.

Why It Matters for Europe

As wind and solar replace large spinning generators, grids lose the physical inertia that slows frequency swings. The European Commission's March 2023 recommendation on energy storage asked member states to plan for non-fossil flexibility, including storage. Flywheels answer one slice of that need without lithium. Teraloop says it targets recycled permanent magnets to avoid dependence on rare earths, and Arteche says 99% of the materials come from European suppliers, while Sky TG24 reported more than 94% of components; neither claim has been independently checked. Isolated grids such as the Azores, where Teraloop has its only documented installations, are where fast frequency support is worth most.

The Corvo project announced in July 2026 would move the flywheel from protecting one factory to stabilising an entire island grid, with EDA's head of innovation saying IANOS "allowed us to validate the potential of flywheel technology in island environments". The size, price and start date of the Corvo system are not public.

The Verdict

Teraloop and the EIC have not been asked for comment for this article. It is based entirely on public records and published statements, linked throughout.