Canada's Bay of Fundy, renowned for its extreme tidal conditions, has long been a testing ground for tidal energy technologies. The region's powerful tides, reaching up to 5 meters per second, have proven challenging for traditional, seabed-anchored turbines. These machines often suffer from blade damage, financial losses, and even total loss when deployed in the Bay of Fundy's treacherous waters. The latest development in tidal energy technology, however, offers a promising solution: a floating, towable turbine that can leave the water when conditions become unfavorable, potentially ensuring its survival. This innovative design, developed by Orbital Marine Power, is set to revolutionize the tidal energy sector.
The Orbital O2, a 680-ton floating turbine, has been operational since 2021 at the European Marine Energy Centre in Orkney, Scotland. Its unique feature is its ability to float and be towed, eliminating the need for permanent seabed anchors. This design allows for easier maintenance and reduces the risk of damage from extreme tidal conditions. The O2's power output is impressive, generating 2 MW of electricity, enough to power approximately 2,000 UK homes and offset 2,200 tons of carbon dioxide annually. Additionally, its output is utilized to produce green hydrogen through an onshore electrolyzer, further enhancing its environmental benefits.
Orbital Marine Power is now developing an enhanced version of the O2, the O2-X, with a power output of 2.4 MW per unit. Six O2-X turbines are planned for deployment in Orkney between 2026 and 2028, supported by two rounds of UK Contracts for Difference. The O2-X's blades are a key innovation, with a project called MAXBlade aiming to extend them from 10 meters to 13 meters, making them the longest tidal blades in the world. This increase in blade length significantly boosts the rotor swept area, potentially reducing costs and improving efficiency.
The Bay of Fundy, with its formidable tides, has become a graveyard for many tidal turbines. The Irish company OpenHydro, for instance, faced numerous challenges in deploying its turbines in the Minas Passage. The region's extreme tidal conditions, with swings of up to 16 meters every six hours, have proven too much for many machines. However, the floating, towable design of the O2-X offers a solution. Orbital Marine Power has partnered with Eauclaire Tidal to deploy up to three O2-X turbines in the Minas Passage, a significant project under Canada's revised tidal permitting process.
The success of the O2-X in the Bay of Fundy hinges on its ability to withstand the region's powerful tides and the streamlined permitting process. The project's timeline includes a deadline of December 2030 for getting a turbine in the water, ensuring the 15-year power contract with Nova Scotia Power. Despite the challenges, the floating design is a significant advancement in tidal energy technology, offering a more resilient and adaptable solution for harnessing the power of the tides.
However, tidal energy still faces cost challenges. The sector relies on government contracts and long-term power-purchase agreements due to its high costs. In the UK's 2024 Contracts for Difference auction, tidal stream projects were contracted at £172 per megawatt-hour, significantly higher than fixed offshore wind's £58.87. The predictability of tidal energy, driven by the Moon's schedule, is a unique advantage, but the question remains whether this predictability justifies the higher costs. As the industry continues to evolve, the floating turbine design developed by Orbital Marine Power may be a turning point, offering a more sustainable and cost-effective solution for harnessing tidal energy.
