Many of us have driven close to, or perhaps even walked underneath, a wind turbine and know what an imposing sight they can be close up. However, land-based turbines are relative small-fry compared to the new generation of offshore generators.
When it comes to wind power, the basic equation is that bigger is better, and with issues of aesthetics and the effect on the landscape removed, the size of new offshore structures is usually limited only by what the engineering can achieve. That said, Donald Trump did bring legal proceedings to try to stop the construction of the world’s most powerful turbines just off the coast of Aberdeen, on the basis that they would be visible from his golf course.
Turbine can power an average home for 24 hours with a single turn
The first turbine went up at the Aberdeen wind farm last month. It stands at 191 metres tall, which is just short of two-thirds the height of the Eiffel Tower. Size really does matter in this case for two reasons. Firstly, the bigger and higher the blades are, the more likely they are to catch the wind. Secondly, the bigger the spin, the more power can be generated. Wind turbines are measured by their capacity in megawatts (MW), and the average offshore turbine is just under 6MW. The Aberdeen monsters are rated at 8.4MW, and it has been reported that a single rotation of the structure’s blades would generate enough electricity to power the average home for 24 hours.
It is hoped that the Aberdeen facility – which will eventually feature 11 of the giant turbines – will be able to generate more than 70% of the Granite City’s domestic electricity needs.
Even bigger turbines are in development
Andrew Canning from Brussels-based advocacy group Wind Europe told Wired: “The average size of offshore wind turbines installed last year was 5.9MW but GE recently announced the development of a 12MW turbine, which is enormous.”
Indeed, GE Renewable Energy announced last month that it would be investing $400 million in developing the Haliade-X, which will be the biggest and most powerful turbine in the world – at least until the next step up. According to GE, it will be 260 metres tall, or almost three times bigger than the Statue of Liberty.
The company said that each Haliade-X will produce about 67GWh annually when sited at a “typical German North Sea site.” This would provide “enough clean power for up to 16,000 households per turbine, and up to 1 million European households in a 750MW windfarm configuration.”
Floating farms can be sited further out
Other innovations include floating wind farms that can be sited further out than traditional offshore facilities.
“We can install turbines further out to sea than we could before, where the wind speeds are higher,” Canning explained.
“They also open up new sea beds – such as the Mediterranean and Atlantic – which were too deep for traditional offshore wind.”
