Harnessing the energy of tidal power could be at a pivotal moment thanks to exciting new technology that is powerful, cost-effective, and easy to deploy.
When it comes to renewables, much has been made of the potential of wind power to decarbonise the global energy mix. Yet for those countries with an extensive coastline, harnessing the power of the seas is becoming increasingly viable.
The UK government for one, says wave and tidal stream energy, which is clean, more consistent, and reliable than wind power, has the potential to meet up to 20 per cent of the UK’s current electricity demand, representing a 30-to-50 gigawatt (GW) installed capacity.
When it comes to tidal power alone, it is estimated that the UK has around 50 per cent of Europe’s tidal energy resource.
Now the Orkney Islands off the Scottish coast are about to start producing tidal energy using a new, state-of-the-art turbine developed by Orbital Marine Power. Designed for easy maintenance and servicing, the O2 2MW turbine has a 73-metre-long hull structure with 10 metre blades that give the O2 more than 600m² of swept area to capture flowing tidal energy, the largest ever on a floating tidal turbine.
How the tidal turbine works
What makes it so exciting is the fact that it is built on land and can be floated to a location and hooked up to an electricity grid. The structure is held on station with a four-point mooring system; and each mooring chain has the capacity to lift more than 50 large buses. Electricity is transferred from the turbine via a dynamic cable to the seabed, with a static cable along the seabed to the local onshore electricity network. It is expected to be in commercial operation for the next 15-18 years.
Orbital’s CEO, Andrew Scott, said, “the O2 is a remarkable example of British cleantech innovation and the build we have completed here is an inspiring display of what a UK supply chain can achieve if given the opportunity – even under the extraordinary pressures of a pandemic.”
Will this type of turbine be the breakthrough needed to make tidal power more commercially successful? After all, cost is an important factor in energy production, and tidal turbines operate in harsh sea environments. Orbital believes so and continues to win more contracts.
The O2 project has been supported through funding from the European Union’s Horizon 2020 research and innovation programme under the FloTEC project, and the European Regional Development Fund through the Interreg North West Europe Programme under the ITEG project. This project has also received support under the framework of the OCEANERA-NET COFUND project and co-funding by the European Union's Horizon2020 research and innovation programme.
Its technology is now being considered for the Isle of Wight, off England’s southern coast, where the tides have the capacity to generate around 300MW of renewable power.
Orbital and the Perpetuus Tidal Energy Centre recently announced plans for deploying up to 15 MW of Orbital’s tidal technology there by the end of 2025, with each turbine able to produce enough energy to power around 2,000 homes and offset approximately 2,200 tonnes of CO2 production per year.
Amy McLellan is a freelance journalist and author. She was formerly editor of Energy Day.