40th Article Series: Offshore wind energy – bigger & bigger
Article written by Tim Camp – Director, Turbine Engineering, LOC Renewables
Today in offshore wind, increasing scale is top of the agenda. Wind turbines themselves are continuing to be designed at ever-larger sizes. From rated powers of 1.5MW which typified onshore turbines only a few years ago, we now have offshore machines which each generate 10MW of power, providing electricity to nearly 9000 homes. General Electric’s Haliade-X turbine will generate 12MW and will be available from 2020.
The scale of the Haliade-X is awe-inspiring. The height of the blade tips, at 260m, is nearly twice as high as the London Eye and nearly three times the height of Big Ben. Each blade is 107m in length, which dwarf the total wingspan of the Airbus A380 at a mere 80m. The area of the rotor disk is over 5 football pitches, while the air passing through the rotor per second at rated wind speed has the mass of fifty London buses.
The continuing trend to larger turbines has been driven by the move of wind energy from onshore to offshore. Given higher balance of plant costs offshore, associated with support structures, sub-stations and longer cabling, it makes sense to install as large a turbine as possible in order to generate as much energy as possible, to offset these costs. As the floating wind industry develops further, we expect turbines to continue to grow in size to offset the higher costs of the sub-structures and moorings.
The scale of individual turbines is not the only thing that is increasing – the amount of energy expected to be generated by offshore wind is also growing. In the UK, the Offshore Wind Sector Deal, announced on 7th March, specified a target of generating more than 30% of Britain’s electricity from offshore wind by 2030. Many believe that this target will have to be increased further given that the costs of nuclear energy – the main low-carbon alternative – are typically twice that of offshore wind.
Although currently the UK leads the world in the development of offshore wind, other countries are rapidly developing their resource. The Peoples’ Republic of China is expected to overtake the UK’s installed capacity by 2021, with annual installations of approximately 2GW, rising to 4GW annually by 2025. Nearby, Taiwan has plans to develop 5.5GW of offshore wind energy by 2025. And the US, despite the climate-change denials of its administration, has a pipeline of offshore wind projects exceeding 25GW.
Both the increase in turbine size and wind farm scale mean that the success of farm design, turbine installation and operation are critical to project feasibility and profitability. LOC Renewables is able to optimise all stages of a project, from concept design to decommissioning. With 40 years of expertise working in the marine environment, combined with turbine-specific skills, we are uniquely positioned to assist our clients in developing ever-larger projects.
