The £968,000 Tidal Bet That Fishermen Can Build Their Own Power

A UK government fund has put £968,000 behind a tidal turbine that arrives in a shipping container and can be bolted together by fishermen on their own quayside. Flex Marine Power, the Scottish company behind the Swimmer Turbine, won the money from the Energy Entrepreneurs Fund after a full-scale sea trial in Northern Ireland in 2020 that founder David Mummery says "finally put us on the map".

The machine is small by industry standards. It generates 50kW, anchored to the sea floor and invisible from the surface — enough electricity for about 30 homes. That is a rounding error next to the giants working Scotland's waters: MeyGen's four 1.5MW turbines on the seabed of the Pentland Firth, or Orbital O2's 2MW floating turbine anchored at Fall of Warness in Orkney.

Mummery's bet is that the small end of the market is the neglected one. He compares his product to flat-pack furniture: "Can you imagine like an Ikea furniture kit? You get a shipping container and you'll open it up and it will be about 20 components. You'll bolt them all together and then you've got your turbine ready." A launch plan follows, and the device goes into the water from a village harbour.

How did the idea start?

The concept took shape underwater. More than a decade ago, Mummery lay beneath a fast-flowing Highland river, holding a cord across the current, and worked out how a turbine should interact with turbulent water. "As an engineer we do the maths and stuff," he says, "but sometimes you can get a lot more from actually touching the water and feeling it." He called the resulting device the Swimmer Turbine.

The route there was not straight. Mummery, a mechanical engineering graduate of Surrey University, once designed robots to pull material out of contaminated nuclear tanks. In 2010 he took a secondment at Scottish Power Renewables on the Pelamis project in Orkney — the 180m "sea snake" wave machine that fed the national grid before its maker went into administration in 2014. "The industry is littered with these examples of fantastic technologies and teams that do brave things that take decades," he says. "But at some point the market doesn't step up and they falter."

Why build small?

The big projects left him uneasy. He surveyed Scottish waters with utility-scale kit weighing hundreds of tonnes, shipped in by mainland crews, while the fishermen he met in harbours looked on. "I thought 'we've got to do this in a way that they can take the lead'," he says. He founded Flex Marine Power in 2011 and spent his early years sketching smaller, lighter designs — building prototypes under a desk in a Glasgow office where the landlord barred his hammer drill.

A former shipyard on the Clyde at Greenock solved the workspace problem. A prototype trialled successfully in 2015 near Oban, on the island of Luing, secured the company's first major investment. Then came the 2020 Strangford Narrows test in County Down, run with Queen's University Belfast under an academic licence: Mummery and his accountant loaded the components into a container, sent them by lorry, and local mariners pulled off a full installation from a farmyard.

What happens next?

Last year, months of testing on Islay put the commercial model through its paces. Mummery rented a boatyard, and "talented local people" assembled and launched the device themselves. "I was standing at the end of the slipway, seeing our machine, without any of my guys touching it," he says. "It was all local people. Fishermen, using their own tractor, launching it down their own slipway. This was my vision in a nutshell."

He returns to Islay next year to generate electricity for the island, and he sees no ceiling on the model: invisible arrays dotted around a single coastline, each owned by different local operators. "In those real coastal communities, they don't have flashy cranes and heavy lifting capabilities and big corporate companies with big pockets," he says. "We're trying to equip real people to thrive by giving them access to the power that's in the tides." If the Islay deployment works at commercial scale, the test will be whether coastal owners — not utilities — become the customer base the tidal industry has spent decades waiting for.