UK explores world’s most powerful tidal turbine to unlock clean energy

Researchers at Plymouth University in the UK carried out extensive surveys around Orbital Marine Power’s O2 tidal turbine, the world’s most powerful and located in the Orkney islands of Scotland, to understand the complex ocean conditions in which tidal turbines operate.

Findings from the study will help the team plan and deploy future tidal energy harvesting systems along the UK coastline. With the demand for cleaner sources of energy surging, wind and solar energy installations have seen a major uptick.

However, both these systems, though widely deployable, are also highly unpredictable. Change in wind speeds or excessive cloud cover on a particular day can drastically drop the energy output from these facilities.

In contrast, energy harvested from tides is regular and highly predictable. Yet, the rollout of tidal energy systems has been slow and faces multiple uphill tasks.

The technology is in the experimental stage, with high scaling-up costs. Solutions for connecting tidal energy to the grid are still in the works. At the same time, functionality in turbulent currents is still unknown.

So, researchers at the University of Plymouth and teams at the Marine Biological Association (MBA) and the University of the Highlands and Islands (UHI) Shetland conducted extensive surveys around the O2 tidal turbine to improve our understanding of tidal energy systems .

The Orbital O2 turbine

Anchored in the Fall of Warness near the Orkney Islands, the O2 is Orbital Marine Energy’s first commercial tidal turbine. The 242-foot (74 m) long structure isn’t like conventional tidal stream turbines and floats on the water surface instead.

Submerged under the water’s surface are two rotors with a blade diameter of 65 feet (20 m) and a 360-degree pitching control ability to ensure safe operations without the need to yaw the platform when the tide changes.

With an output of 2 MW, it is the world’s most powerful tidal turbine. It generates enough energy to power 2,000 homes in the UK and offset 2,200 tonnes of carbon dioxide every year.

What did the survey find?

With the O2 turbine demonstrating tidal energy technology, researchers were keen to understand how tidal flows greater than eight knots (four meters per second, nine miles an hour) would affect the device’s performance.

Using aerial drones and boats, the researchers mapped complex tidal flows faced by the turbine and the impact of its presence on other tidal turbines placed downstream.

The researchers gained insights into the optimal placement of tidal turbines if they have to be deployed in an array to generate larger energy output. These real-world measurements helped the research team close the gap between predictions from computer simulations and observations at specific sites.

Interestingly, in a previous study, the research team found that turbine wake produced a favorable foraging spot for seabirds. By not packing the turbines too closely in the array, the researchers suggest that energy infrastructure would also allow the movement of marine animals.

“This study showcases the benefits of combining scientific expertise and deploying new technologies so that significant progress can be made in understanding dynamic tidal environments,” said Shaun Fraser, a senior scientist at UHI Shetland, in a press release .

“With further development of marine renewable energy infrastructure in the Highlands and Islands region likely in the near future, this work is more relevant than ever to local industries and communities.”

The research findings were published in the journal Nature Communications .