Solar farms and land use in a changing climate

Jonty Haynes, senior analyst, Regen

Both Liz Truss and Rishi Sunak have declared 'our fields shouldn't be full of solar panels'. However, a look at the data shows that the real risk to our fields is climate change, not solar. Even a hugely ambitious solar farm rollout in the UK would only require a tiny fraction of the UK's lower-grade agricultural areas, while the impacts of climate change could threaten vast swathes of the UK's highest quality farmland

Let's do the maths

In the two National Grid ESO Future Energy Scenarios that achieve net zero in 2050 (Consumer Transformation and System Transformation), solar farm capacity across Great Britain reaches 35-40 GW. Lets take the top end of that, to be conservative.

All in, solar farms in the UK have historically required around two hectares of land per MW of capacity. With panel power densities increasing all the time this is almost certain to decrease, but again, lets take the worst case.

So 40 GW, at two hectares per MW, that gives us a maximum solar farm land use of 80,000 hectares (or 800 square kilometres). The interactive graphic below compares this potential land use against other forms of land cover in the UK.

Breakdown of UK land cover, and potential solar farm land use

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Source: CORINE land cover map dataset. Mobile and tablet users may want to use the arrows along the top of this story to find the solar farm 2050 land use, which is in their own yellow circle.

Less than 0.5% of farmland. Let's compare that to the impact of climate change.

So our upper-end estimate ends up with solar farms covering 0.3% of the country, or 0.5% of farmland, in 2050, to hit net zero by 2050. Due to current planning guidelines, solar farms are predominantly being developed on low grade 'moderate quality' and 'poor quality' agricultural land, and these restrictions haven't prevented solar developers identifying over 20 GW of prospective large-scale solar pipeline projects. Rather than filling fields with solar panels, this provides a valuable revenue stream for owners of poorer quality, lower value farmland. 

As an aside - solar farms can also hugely improve local diversity, allow intensively-farmed soil to recover, and even allow sheep and other animals to graze under and around the panels. So this very small proportion of farmland that may be used for solar farms isn't even 'using up' the land, but rather working symbiotically with other land improvements.

However, there is something that could strongly impact high grade farmland, and that's the impacts of climate change. The parliament POSTnote on Climate Change and Agriculture notes that:

"More frequent extreme temperatures and changes to rainfall patterns will lead to overall negative impacts on production in the UK"

Not only will UK agricultural production be negatively impacted, but a huge proportion of our highest-grade land is severely at risk of coastal flooding by 2050. Worryingly, Climate Central's map of areas at risk of sea level rise by 2050 shows that over 55% of the UK's highest grade agricultural land, located in Lincolnshire, Norfolk and Cambridgeshire, is at risk of climate change induced flooding by 2050.

To protect the country's farmland, drastically reducing carbon emissions should be top of the agenda.

What do people think about solar?

Farmland is not just about agricultural production, it's also part of the national landscape. Over two-thirds of Tory members support solar farms. Of the wider public, the BEIS public attitudes tracker from spring 2022 has some interesting views from the wider electorate:

  • 71% of Conservative party members support solar farms

  • 87% of people say they support solar developments

  • Just 7% of people said they would be unhappy for an onshore wind or solar farm to be constructed in their local area

So some strong evidence, even with regards to solar farms in peoples' local areas.

In conclusion

From the data, it seems that:

  • Solar farms will need at most 0.5% of UK farmland by 2050, predominantly on poor quality, low value land 

  • The impacts of uncontrolled climate change will harm UK farming and farmland landscapes far more than solar farms ever could 

  • The vast majority of the public are strongly in favour of solar farms, even in their local area

With that in mind, this challenge against solar land use in the context of the current energy crisis and increasingly evident impacts of climate change seems hugely misguided. Solar power is very low cost, renewable, and popular with the public. As I see it, if even solar farms are up for debate, I feel like the chances of reaching net zero carbon by 2050 seem slim.

Of course, there is another form of energy that is proven to be low carbon and low cost, and not only provides revenues for UK farmers, but also allows farming to continue around it...

Image of Carland Cross Wind Farm from Cornwall and Isles of Scilly Growth Programme