Alan Gooding, director and co-founder of Smarter Grid Solutions, explains that the secret to harnessing offshore wind lies back on dry land.
The growth of offshore wind power is nothing short of astounding. The UK’s capacity already sits at 8GW, with 2GW added during 2018 alone, and energy minister Claire Perry wants that total to rise to 30GW by 2030, enough to provide a third of the electricity Great Britain needs.
Engineers are already rising to the challenge of installing scores of turbines around the coast. Yet harnessing the full power of the wind out at sea will also require changes in the way the electricity system is managed back on dry land.
As anyone who’s ever stood on a beach can testify, the wind doesn’t blow at a constant speed all day long – sometimes it comes in strong gusts and sometimes it drops completely, leaving a perfectly still day. That intermittency sits at the heart of the challenge of integrating offshore wind.
Wind farms can be spread out along the coast to help smooth out some of the variability in the wind; after all, if it’s a calm day down in Cornwall then the wind may still be blowing up in the Highlands of Scotland. That geographical smoothing can only go so far though – the variation in the output from wind farms out at sea can’t be balanced with consumer demand for electricity without help from somewhere.
These powerful wind farms have a capacity measured in gigawatts and so the fluctuations in their output are equivalent to that of a nuclear power station being brought online and offline. An equally-pressing problem is what happens on days when the wind simply doesn’t blow, causing headaches for those trying to balance supply and demand across the wider grid.
Like all renewables, offshore wind’s installation cost is high, but the production cost is virtually zero because the fuel is ‘free’. That makes offshore wind a very cheap form of energy when it’s available and the owners and operators of these giant resources must export electricity to the grid whenever possible to repay the investment in the construction of the assets.