From an average offshore wind farm capacity of just under five megawatts in 2000, to nearly 90 MW in 2005, offshore wind farms have ballooned in size. Although the average size of offshore farms saw a peak in 2005, they are on the rise again: in 2008 the average size was 62.2 MW, rising to 72.1 MW in 2009.
As the technology progresses, so does the power of the offshore turbine. In 1998, the average offshore wind turbine had a capacity of just over 0.5 MW, but today the towering wind turbines have a capacity of up to 4.5 MW. In 2009, the average capacity was just under this at around 2.8 MW.
Up to 2002, no turbines were installed in water depths greater than 10 metres. Since 2006, the average water depth of a wind turbine has been over 10m peaking in 2006 with an average depth of just less than 20m. The foundations of future offshore wind turbines, however, are likely to sink even deeper – offshore wind farms currently under construction have an average depth of 21.8m. That’s not to mention the potential for floating turbines which today are in the prototype phase.
All at sea
Offshore wind farms are being located further and further from the shore. In 2009, the average distance to the coast was 14.4 km, 3.9km further than in 2008. The majority of offshore wind farms are still closer than 20 km, but wind farms under construction are at an average distance of 30.1km from the shore.