How much of the UK’s area will be taken up with 100 per cent renewable energy?

not as much as you might think!

The large bulk of UK energy supplied under a 100 per cent renewable scenario could be generated using no more than 4 per cent of the UK’s surrounding waters for offshore wind farms. The rest will come mainly from onshore solar and wind sources.

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This book shows how we can move forward to an energy system powered by renewable energy rather than nuclear power or ‘carbon capture’ fossil fuels. It reveals how selective public ownership and targeted interventions, as part of an energy democracy programme will protect consumer interests better than the chaotic energy supply system that failed consumers so expensively in the recent energy crisis. We want no more of that!

Estimates of the annual amount of energy needed under a (2050)  net zero carbon scenario vary. But one that I had a big hand in commissioning, from LUT University in Finland, suggests that about 1200 TWh a year will be needed at most. See HERE for details and links to this study. This assumes that energy is delivered in the form of electricity with some green hydrogen and green synthetic fuels (i.e. made using renewable electricity) used for storage and other purposes.

So where would 1200 TWh come from in a 100 per cent renewable energy scenario?

I make some plausible assumptions about onshore wind and solar generation. Assume that onshore wind generation can increase to around double its current generation, to say 70 TWh per year. If solar pv covered the roofs of the majority of UK buildings and one per cent of the UK land was occupied by solar farms then we could generate  300 TWh per year from solar pv. Add on top of that, let’s say another 40 TWh of renewable energy from other sources including hydro, tidal, wave, geothermal and biogas (40 TWh may well be an underestimate here) and we have at least 400 TWh – which is about a third more than current UK electricity consumption.

So if total annual energy (that is all energy) consumption for net zero is going to be 1200 TWh a year and we subtract 400 TWh from 1200 TWh then that leaves a further 800 TWh of energy that would have to come from offshore wind farms (or something else of course).

Now using the figure of 3 watts per metre said by  (on page 60) by McKay to be delivered by offshore wind, the 800 TWh of energy from wind power would come from around 30,000 square kilometres. This works out as being almost exactly 4 per cent of the UK’s offshore Exclusive Economic Zone (EEZ). It certainly seems that with the development of floating offshore wind technology water depth will not be a limitation on where offshore windfarms can be sited. Given the increase in the efficiency of succeeding models of wind turbines 800 TWh will be generated in the future from around 160GW of installed offshore wind power.

Of course there are still competing uses for offshore resources including biodiversity habitats, bird flight paths, shipping routes, fishing and minerals. Ecologists will have sympathy for protecting marine habitats, but less sympathy with industrial activity such as fishing using bottom trawling. But utilising around 4 per cent of the UK’s waters does not seem to be an unwarranted call on our resources in the cause of eliminating carbon emissions from energy generation.

Finally of course there is the question: can the UK Renewable Energy industry possibly deliver this amount of offshore wind (i.e. 160GW)? Well, for starters, according to RenewableUK, the trade association, there is already around 100 GW of offshore wind capacities being scoped or in some form of planning stage!