On a sunny October morning, our boat passes the run-down relicts of Liverpool’s maritime past and heads down the river Mersey and into the Irish Sea. As we steam offshore, I see in the distance a cluster of tall structures that soon reveal themselves to be towers of a wind turbine array. Arriving at the windfarm, six miles offshore, the turbines rise as high as 650ft, taller than the tallest church in the world. Each of the turbines’ three shiny metallic rotor blades is nearly 300ft long.
“A single rotation of an eight-megawatt turbine will cover the daily electricity consumption of an average British household,” says Benj Sykes, vice president of Dong Energy Wind Power, the company that is constructing and co-owns this wind project, as the boat rocks in five-foot swells.
Workers have been busy at the Burbo Bank extension, named for this patch of the Irish Sea, since June, using gigantic cranes to drive foundations 50ft into the sea floor. With a design capacity of eight megawatts each, the 32 turbines are the most powerful ever installed at a commercial offshore windfarm. Once the rotors start spinning later this year, the Burbo Bank windfarm will be able to power 230,000 households – enough to run Liverpool city, with its 466,000 inhabitants.
In Europe, offshore wind farms like the one at Burbo Bank are undergoing a boom. While still significantly outnumbered by windfarms on land, the importance of windfarms at sea has grown dramatically in the past several years. Until 2011, between 5 and 10% of newly installed wind energy capacity in Europe was offshore. Last year, almost every third new wind turbine went up offshore. That growth has helped boost the share of wind energy in the European Union’s electricity supply from 2% in the year 2000 to 12% today, according to WindEurope, a business advocacy group.
New investments for offshore projects totaled $15.5bn in the first half of 2016 alone, according to WindEurope, and newly installed offshore wind energy capacity will double to 3.7 gigawatts this year compared to 2015. More than 3,300 grid-connected turbines now exist in the North Sea, the Baltic Sea, and the Irish Sea, and 114 new wind turbines were linked to the grid in European waters in the first half of this year alone. This is in stark contrast to the US and Asia, where offshore wind use is only just getting started.
The offshore wind boom is part of a wider move from fossil fuels to renewable energy across the European Union. The overall share of renewable electricity sources in the EU – hydropower, wind, solar, biomass, and geothermal – has gone up from about 15% in 2004 to roughly 33% in 2014, according to data from Eurostat and Entso-E, the association of grid operators. Along with solar photovoltaic power, wind energy is driving this expansion. Newly installed wind energy capacity amounted to 13 gigawatts in 2015, twice as much as newly installed fossil fuel and nuclear capacity combined. WindEurope claims that all European wind turbines taken together can now generate enough electricity for 87m households.
This is not only a result of government subsidies and incentives, but also of dramatically reduced production costs for wind energy. The price for a megawatt hour is now between €50 and €96 for onshore wind and €73 to €140 for offshore wind, compared to around €65 to €70 for gas and coal. Electricity generated from onshore windfarms is now the cheapest among newly installed power sources in the UK and many other countries. If environmental costs are considered, the picture looks even more favorable for wind power.