This is entry number 168, first published on 24 September 2010, of a blog on the implementation of the Planning Act 2008. Click here for a link to the whole blog. .

Today’s entry reports on the latest developments in UK offshore wind power.

Thanet Array switch-on

Yesterday, the world's largest offshore windfarm was switched on, off the coast of Kent. Developed by Swedish energy company Vattenfall, the Thanet Array has 100 3MW turbines manufactured by Danish company Vestas. The windfarm was originally being developed by Warwick Energy, who sold it to a hedge fund in 2007, who in turn sold it to Vattenfall in 2008. This means that the UK now has 1341MW of offshore wind power, which is more than 50% of the global total.

These figures are impressive, but before we get too carried away, do not forget that onshore wind power is more developed and currently much more extensive. The World Wind Energy Association predicts that the global total of wind capacity will top 200GW by the end of this year, of which offshore wind will exceed 2GW, so just over 1% of the total. The world's largest windfarm is a 780MW windfarm in Texas, and the largest in Europe is a 500MW windfarm in Albania.

Nevertheless in the next few years a dramatic increase in offshore wind power is planned in the UK and elsewhere (see below). In the UK it is to meet the lion's share of the EU target of 15% of energy to come from renewable sources by 2020, contained in the Renewable Energy Directive. That is a tougher target than it might seem since it applies to energy overall, rather than just electricity production.

As a rough rule of thumb, 1/3 of energy consumption is in the form of electricity, 1/3 is in the form of gas for heating, and 1/3 is in the form of oil for transport. Thus since fuel for heating and transport are not likely to shift dramatically to renewable sources in the next ten years, other than being replaced by electricity, electricity is going to have to take up the slack and produce much more than 15% from renewable sources. Indeed, the government's Renewable Energy Action Plan envisages 30% of electricity coming from renewable sources by 2020, 12% of heating and 10% of transport. Given that only 3% or so of energy came from renewable sources in 2009, there is a long way to go.

Wind energy share milestone

There was promising news on this front recently, however, as another landmark was reached on 6 September. More than 10% of the UK's electricity was declared to have been produced by wind power for the first time. According to this nifty webpage which provides live data on where our electricity comes from, the figure has gone back down to a more normal 2.7% since then, even since the Thanet Array switch-on. I recommend checking this website every so often to see the true picture of electricity sources. To use it, click 'Hide all' on the left and then 'Generation by Fuel Type (table)'. You will see that 50% of electricity still comes from gas ('CCGT') and 27% from coal. The other categories are nuclear (14%), pumped storage ('PS' - where water is pumped up a hill at night and let down again during the day to create hydroelectricity when there is higher demand for electricity) (1.1%), hydroelectric ('NPSHYD') at 1.3% and finally electricity arriving from France ('INTFR') at 3.1%.

Offshore wind and the Planning Act

The Planning Act regime applies to offshore windfarms that will have a capacity of more than 100MW, which is about 33 of today's 3MW turbines. Turbines are getting more powerful, however - the Energy Technologies Institute is planning to test a 15MW turbine in Northumberland next year - so we can expect arrays of fewer, larger turbines to be considered by the Infrastructure Planning Commission (IPC) (or its replacement) in the future. There are currently 11 offshore windfarms in the IPC pipeline, although no applications have yet been made for them:

  • Atlantic Array (RWE Npower) 1500MW
  • Burbo Bank extension (DOng) 234MW
  • Dogger Bank (Forewind - SSE, Statoil, Statkraft, RWE Npower) 13000MW
  • East Anglia (ScottishPower) 7200MW
  • Galloper (SSE, RWE Npower) 504MW
  • Hornsea (SMart Wind - Siemens and Mainstream Renewables) 1500MW
  • Irish Sea (Centrica) 4200MW
  • Isle of Wight (Eneco) 4200MW
  • Rampion (E.On) 665MW
  • Triton Knoll (RWE Npower) 1200MW
  • Walney extension (Dong) 768MW

That adds up to 35GW, but since wind turbines operate at an average of about 30% of their full capacity, would represent about 10GW of electricity production. This is roughly one-sixth, or 17%, of the UK's current electricity consumption. There is therefore still a lot more to do to meet the UK's energy target by 2020.