Coastal challenge: A search for solutions at sea
Wind power has been used as a source of energy for thousands of years, with the first wind turbine used to generate electricity dating back more than a hundred years, to 1887 in Scotland. Traditionally, wind farms have been built on land – and many still are. Late last year, Swedish authorities gave the green light to a 650mW onshore wind farm. China’s massive Gansu Wind Farm, meanwhile, has some 7,000 turbines, and will achieve a capacity of 20,000mW by 2020. But in many countries, limited land resources, and topography that disrupts wind flow mean that extremely large utility scale onshore wind farms like Gansu simply are not viable.
Offshore windfarms however, have opened up more possibilities. Located at sea rather than on land, these wind turbines no longer pose a source of conflict for communities. Indeed, in many regions, offshore wind has become an industry in its own right. Per industry group WindEurope, Europe’s current offshore wind capacity is set to almost double in the next two years, reaching a combined 25GW by 2020. In fact, 2017 was a record year for offshore wind power in Europe, with 4,000 offshore turbines now operating across 11 countries.
However, the challenge with conventional offshore windfarms is that it requires a shallow seabed of water depths up to approximately 50 meters for turbines to be mounted. Globally, the coastlines with this shallow water depth are limited. These areas often have the most traffic from ships, are crossed by cables, and contain the most environmentally sensitive sea life.
“The proportion of the seas that this water depth exists is very small. Moving further opens up huge further potential for wind power generation,” explains Nigel Crowe, Business Line Manager of Renewables and Wind at TÜV SÜD. The introduction of floating windfarms has the potential to change this dynamic. When turbines are placed further offshore, they benefit from faster, steadier and therefore more usable wind.