What Became of Turbulent's EIC Accelerator Vortex Hydro Turbines

Most engineers try to keep turbulence out of a turbine. Turbulent, a start-up from Leuven, built its business on it. Its turbine diverts part of a river or canal into a round concrete basin with an outlet in the floor, so that the water spins into a whirlpool and drives a slow-turning impeller on its way out. It needs a drop of only about 1.5 metres, no dam, and, the company says, lets fish pass unharmed.

In April 2019 the European Commission selected the company in a round of the EIC SME Instrument Phase 2, the Horizon 2020 programme that became the EIC Accelerator, and gave it an EU contribution of €2,458,050 towards a €3,511,500 project, according to CORDIS. The proposal promised 37 employees by 2023, profitability in 2021 and a cumulative EBITDA of €64 million over five years. Turbulent's filed accounts show an average of 4.3 full-time staff in 2023 and one profitable year out of six. In December 2025 it was acquired by EnergyVision, a Ghent energy supplier listed on Euronext Brussels.

Where Turbulent Stands Now

Turbulent is now a business unit of EnergyVision. The buyer announced the deal on 4 December 2025, saying hydropower would add a steady, round-the-clock source to its solar and wind portfolio, and that Turbulent would keep its brand and continue to build projects abroad while also developing installations in Belgium, according to EnergyVision's press release, also reported by M&A Belgium. Turbulent's chief executive Pieter Joseph said its international pipeline for 2026 held more than €5 million of signed projects. The price was not disclosed.

Part of it was paid in EnergyVision shares. The listed company transferred 36,409 treasury shares at €10.30 and 5,192 at €10.98 to Turbulent's former shareholders in December 2025, according to a regulatory notice, and a further 1,579 shares at €9.50 to Spreds Finance, the vehicle of Turbulent's crowd investors, in February 2026, according to a second notice. At those prices the 43,180 shares were worth about €447,000. Whether cash was also paid is not public.

The Belgian company register shows the company active, its seat moved to EnergyVision's address in Ghent on 3 March 2026, and its board made up of EnergyVision chief executive Maarten Michielssens, Koen Decourt and the founder Geert Slachmuylders. Slachmuylders had left his operational role in 2022 and returned to the board in May 2026, according to Forbes Belgium; North Data lists his removal as managing director in July 2022. Pieter Joseph no longer appears among the directors in the register; the register's last publication, in July 2026, records resignations and appointments.

The Technology: A Whirlpool Instead of a Dam

Conventional small hydropower needs a head, a height difference, of several metres, usually created by a weir or dam, and a turbine sized for the site. Very low drops of under 3 metres, found at old mills, weirs and irrigation canals, are mostly left unused. Turbulent's gravitational vortex design is meant for those sites: one unit works from a drop of 1.5 metres and a flow of 1.5 cubic metres per second and delivers 15 to 90 kW, according to the company; the Forbes Belgium article gives a yearly output of 100,000 to 600,000 kWh per turbine. A 2022 profile by Innovation Origins put a typical installation at about €200,000.

The EIC proposal claimed the design doubled energy output for the same size, cut civil works by more than half and produced power at €0.026 per kWh, against €0.06 for solar. Those are the company's figures. No independent measurement of the cost of energy across its fleet has been published, and the fish-friendliness tests it planned with live fish at a 7.5 kW UK Environment Agency site in Denver, Norfolk, were due in 2022, according to its projects page; no results could be found.

What the EIC Project Promised, and What the Record Shows

The project ran from 1 August 2019 to 31 December 2022. When it was proposed, Turbulent said its technology was at TRL 7, with two full-scale demonstrators and one commercial installation running. It asked for the grant to scale up after "a first seed round of €1.6M", with a commitment for another €1.6 million in 2020. The European Commission's list shows Turbulent, then based in Hasselt, as the only beneficiary of the project.

Only the report for the final period, April to December 2022, is published on CORDIS. It says the company built a computational fluid dynamics tool and a site evaluation tool, improved the core turbine for efficiency and manufacturability while keeping production in the EU, and worked on the electrical systems for off-grid use and for several turbines working as one unit. "The result has been a few installed demonstrators and more to come in the pipeline," it says, adding that the turbine in Bali was "performing as expected nearly continuous" and that Covid had hurt business development. It gives no revenue, sales or staff figures.

1. Market-ready vortex turbine, produced in the EUDeliveredUnits installed in Bali, Kenya, Taiwan, the Azores and Belgium, per the company and NewMobility.
2. Site evaluation and design toolsDeliveredCFD and site tools reported in the final CORDIS report.
3. 37 employees by 2023Missed4.3 average FTE in the 2023 accounts.
4. Profitable from 2021MissedLoss of €722,973 in 2021, profit in 2022 only, losses in 2023 and 2024.
5. €64M cumulative EBITDA in five yearsMissedGross margin no higher than €514,268 in any year from 2019 to 2024.
6. Fish-friendliness proven in live testsUnverifiedUK test site announced for 2022; no results found.

The Turbines in the Field

Turbulent's first commercial pilot, 15 kW on an irrigation canal serving a farm in Doñihue, Chile, began running in January 2018. A video of it drew 100 million views and more than 10,000 requests, the company said when it announced a €3.2 million funding round with Inventures and Victrix in March 2019. Its crowd round on Spreds, part of a €1.6 million raise, reached 250% of its target with more than 160 backers.

Since the award, the largest installation the company lists as running is three 37 kW turbines on the Mathioya river in Murang'a County, Kenya, feeding a micro-grid developed by Hydrobox Kenya, with support from the Flemish government and G-STIC, according to its October 2023 post. It also lists a 100 kW unit in Yilan, Taiwan, which it calls the first micro-hydro plant in a natural river there; two 30 kW units in the tailrace of a hydropower plant of the utility EDA Renováveis in the Azores, installed for operation in December 2024; and smaller units at the Green School in Bali, at a Suez wastewater plant in Versailles and at a house in Estonia. Apart from the Belgian site, these projects are documented by the company and not by its customers.

The Belgian turbine is the best documented. Princess Astrid opened a 15 kW unit in a 13th-century watermill in Papignies, Lessines, on 17 June 2025, which Turbulent calls its first turbine on a navigable waterway in Belgium, as reported by NewMobility and the company's own post. The pipeline on its projects page includes eight 90 kW turbines for an irrigation system in the Philippines and smaller plants in South Africa, Colombia, the Democratic Republic of Congo and Idaho, none of which is reported as running.

Counting the operational sites the company lists gives about 324 kW. In 2022 the company told Innovation Origins it had sold 390 kW in 2021 and was aiming for 10 MW by 2025. No public source shows that target being reached.

The Money

The accounts filed with the National Bank of Belgium show a company that stayed small. It lost €1,049,367 in 2019, the year the grant was signed, and only €56,943 in 2020. It lost €722,973 in 2021, made a profit of €184,247 in 2022 and lost €652,888 in 2023. In 2024 its gross margin turned negative at minus €487,346 and the loss rose to €1,722,329; equity fell from €2.33 million to €307,779 while debts more than doubled to €2.15 million. The same figures appear on Companyweb. Accounts for 2025 had not been filed by the date of this article.

Shareholders kept funding it. Registered capital rose from €1.6 million in August 2018 to €2,010,746 in January 2021, €3,394,186 in January 2023, €3,469,186 in January 2024 and €4,339,978 in January 2025, according to North Data's summary of the Belgian Official Gazette; the register shows €4,339,977.91. North Data also lists Flemish state aid of €700,000 in 2021 and €1,648,681 in 2024 under the region's international climate finance calls, which match the Flemish support the company cites for its Kenyan and South African projects. It also lists an EU award of €2.5 million in December 2025 for a project called "Empowering Rural Zambia"; no other source for that award could be found.

Why Europe Should Care

New dams in Europe face the Water Framework Directive's rules on river continuity, while weirs and old mill sites like Papignies already exist. A small, fish-friendly turbine that produces steady power where solar and wind do not is the kind of decentralised, low-carbon generation the European Green Deal cited in the CORDIS report calls for, and Turbulent kept manufacturing in the EU. EnergyVision's own case for the deal was baseload: "when the sun does not shine and the wind does not blow, rivers keep flowing", its chief executive said (translated) in the company's 2025 annual results.

The limits are just as clear. Each turbine produces tens of kilowatts, and much of Turbulent's business ran in Asia, Africa and Latin America, not in Europe. Forbes Belgium noted that EU water and nature restoration rules still constrain new installations, that the economics at industrial scale remain unproven, and that no list of concrete Belgian sites has been published. Belgium has about 180 MW of hydropower in total, the same article says.

Sources disagree on when the company began: the register dates it to 12 January 2015, Forbes Belgium to 2015 in Leuven, while Innovation Origins gave 2014.

The Verdict

This article is based entirely on public records and published statements, linked throughout. Turbulent, EnergyVision and the EIC were not asked for comment.