A rumoured plan from the Department for Environment, Food and Rural Affairs to dramatically restrict solar panels on farmland in the UK will not help food security – which is threatened far more by climate change – let alone energy security, and is at odds with the Government’s Net Zero Strategy. The UK should be seeking to invest and innovate in ‘Agri-PV’ schemes instead, writes Leo Mercer.

The premiership of Liz Truss has got off to a rocky start. Fiscal policy aside, Downing Street’s approach to resolving the energy trilemma (finding a balance between security, affordability and environmental sustainability) is uniting many in opposition: so far, permitting rounds for North Sea oil and gas exploration have been opened up and fracking is back in the frame. This week there have been reports of an intervention in the renewable energy market in the form of a move to reclassify some agricultural land so that solar arrays would be banned from most farmland across England. It is understood that the new Secretary of State for Environment, Food and Rural Affairs, Ranil Jayawardena, wants officials to extend the definition of “best and most versatile land” (BMV) to include grade 3b land, described as “moderate quality agricultural land” – although the Business Secretary, Jacob Rees-Mogg, who has energy and climate change in his remit, is allegedly against the idea.

The policy would guide planning authorities to restrict ground-mounted solar PV developments on BMV land to protect agricultural production, and is ostensibly to protect British farmland so that it can be optimised for food production. Presently, land classified up to subgrade 3a is earmarked solely for agricultural production, with much of the recent solar PV development occurring on subgrade 3b land. Of course, the best and most versatile agricultural soils should be protected from ill-conceived development such as low-density urban sprawl. Ensuring that food production is protected and prioritised alongside emissions abatement is also enshrined in the 2015 Paris Agreement. But this proposal represents a significant ideological intervention in the energy market and conflicts with the urgent imperative to improve domestic energy security and reach net zero emissions by 2050.

What is behind the plan and how will it affect planned solar supply?

The encroachment of ground-mounted solar PV arrays (referred to as solar PV) onto farmland is considered to run counter to Downing Street’s 2022 Growth Plan, in which agricultural productivity has been described as being “weak for many years”. The Government has committed to “…review frameworks for regulation, innovation, and investment that impact farmers and land managers in England”. Other objections relate to preserving landscape and amenity value, although the location of solar farms can be controlled through planning processes: for instance, restricting developments near roads and in Areas of Outstanding Natural Beauty would alleviate some of these fears.

The extent to which this decision will impact the objective for a fivefold increase in solar capacity, from 14GW presently, to 70GW by 2035 to provide “long-term energy security”, has not been articulated or costed in the Growth Plan. Tom Bradshaw, deputy president of the National Farmers’ Union, has stated that if every project planned is completed, only 0.28% of land would feature solar panels. According to CarbonBrief, this is the equivalent to around 0.5% of the land currently used for farming – and roughly half of the space taken up by golf courses. Meanwhile, reporting in the Financial Times has indicated that putting the restrictions on PV arrays in place may imperil up to £20bn investment in renewable energy for 30GW of proposed projects.

Cost is not an argument against solar. Utility scale solar photovoltaic (PV) generation has seen a significant decrease in the cost per unit of generation to develop new arrays over the past two decades. For utility-scale solar PV systems, the cost has come down by 82% since 2010, making renewable energy much cheaper than fossil fuel alternatives in many instances – although the cost per Mwh in smaller scale agricultural projects lags behind dedicated solar farms, which have scale advantages.

Innovations in ‘Agri-PV’

The biggest threat to British food production and security is not solar PV generation on moderate quality agricultural land but is in fact climate change. As the 2022 summer heatwave has shown, the UK is poorly equipped to deal with the extremes wrought by a changing climate. For farmers, higher than average mean summer temperatures and heatwaves in July and early August brought widespread reports of crop failure, incidents that will continue if global mean temperature rise is not limited to 1.5°C.

Interestingly, rural organisations such as the National Farmers’ Union and the Country Land Business Association have in recent years been supportive of integrating solar power generation with rural landscapes. They view it as a sound diversification strategy which provides farmers with a reliable source of income. And indeed a plethora of examples of solar power generation being integrated with food production exist, in the UK and beyond.

These approaches are commonly referred to as Agri-PV. Zimmermann PV-Agri, for instance, have integrated solar panels into a variety of horticultural operations. One such project in Babberich, Eastern Netherlands, has covered a 3.3 hectare raspberry crop (which are shade-tolerant and need shelter), with 10,250 specially designed wide-spaced solar panels to generate 2.67MW of renewable electricity alongside the high value berries – enough energy to power up to 1,250 households. No decrease in yield or quality of berry has been recorded, electricity is sold back to the grid, there are no plastic tunnels to repair when damaged by storms, and the area under the panels is cooler, more pleasant to work in and requires substantially less irrigation than tunnels. So there are significant benefits for farmers to such an approach.

In the UK, there is guidance that grazing can be integrated with solar power generation at similar stocking densities to conventional farming. Other widely cited evidence from the University of Oregon exploring lamb growth and pasture production on Agri-PV and control paddocks found little change in lamb weight gain and a slight reduction in the quantity of forage, which is offset by improvements in quality. Other benefits for livestock include provision of shade and shelter.

There is plenty more evidence that solar power generation can be integrated well with existing agricultural or horticultural operations. The co-benefits in terms of food and energy security should be something all governments look at closely.

The future is for ethical and innovative farming

The proposed policy harks back to a time of old where a high input model of farming was pursued at the expense of the natural environment. That model is one that British farmers themselves no longer wish to pursue, as the backlash this month against the review of the Environmental Land Management scheme has highlighted. Consumer preferences are changing too, with a growing demand for food produced ethically and in sync with the environment. One can easily see British produce produced in tandem with renewable energy being able to earn a market premium and drive growth in the sector in a way that supports the environment.

James Murray of Business Green states that by demonising these projects, the proposed policy is “investment chilling policy uncertainty … for solar developers and investors in nature-based solutions”. The UK Government has committed to becoming a technology and innovation powerhouse. Downing Street needs to consider the negative impact this policy would have on these goals. Above all else, investors need policy certainty to guide long-term investment strategies. While the highlighted projects show what the future of British agriculture could be, this is still a nascent area and there is a need for UK-based research to ramp up and support the international findings. If done well, there is plenty of scope for the UK to become a leader in developing hybrid land uses such as Agri-PV.

The views in this commentary are those of the author and do not necessarily represent those of the Grantham Research Institute.

Keep in touch with the Grantham Research Institute at LSE
Sign up to our newsletters and get the latest analysis, research, commentary and details of upcoming events.