What if... the world switched to wind power?

The ongoing debate over wind power intensified last week when Tory minister John Hayes claimed 'Enough is enough!'. Wind farms are causing an irreversible blight on our green and pleasant land and new developments must be stopped.

Whatever your thoughts on wind turbines (personally I think they're beautiful, certainly less of an eyesore than the pylons that stretch across the countryside) there's no denying that there's more of them about these days. The world produces 13 times more energy from wind now than it did at the turn of the century. But I was surprised to find that, despite the Sustainable Energy commission stating the UK has the 'best wind resources in Europe', it produces relatively little wind power compared to its European counterparts. Take Germany for instance. According to the IEA, Germany produces 6% of its electricity from wind and the UK, just under 3%. So we can't be that hard done by.

But just how bad could things get? What if the entire world switched to wind power?

If you're looking for energy stats, there aren't many better sources that David Mackay's brilliant Sustainability without the hot air. Mackay looks at the numbers to bring a much needed level headedness to the energy debate. In the video below he outlines the huge scale of the energy challenge more concisely than I could ever hope to.

Mackay calculates that covering 10% of the UK in wind turbines (An area bigger than Wales) would produce 20kwh a day per person of energy - half the energy used to drive a 50km daily commute. Of course, stronger winds mean there's greater potential for generating energy out at sea. Mackay calculates that, if the shallow waters around the entire UK coastline were covered in a strip of turbines 4km thick (total area 13,000km²) we'd get an additional 16 kwh a day per person. Currently we're limited to these shallow waters  - wind turbines in deeper waters are just not economically viable.

So if we covered Wales in wind turbines and fully exploited our coastal waters, wind power could produce 36kwh a day per person - a long way short of the 195kwh a day we currently use.

Norwegian company Statoil have developed floating wind turbines that could be used in deep waters

The average person on Earth uses much less energy than us - about 56kwh a day per person. So how big an area would we need to provide this energy with wind turbines alone? Well if we assume global wind speeds are similar to those Mackay has used for his UK calculations (a gross simplification I know) and there are 7 billion people on the planet - a quick calculation reveals you'd need to cover 6.85 million km² of land in wind turbines - about twice the size of India!

When it's put like this, the need for an energy mix is obvious. It's impossible to rely solely on one energy source such as wind - the engineering challenge would be unimaginably big. And that's before we've even considered that it's not windy all the time. So if we want to make sure we can produce electricity 24/7, we a range of energy sources.