The proposal for Europe’s largest solar farm

The Botley West solar farm will consist of three large areas of photovoltaic panels immediately to the west and north west of Oxford in central England. In total, the proposal envisages a plant of 840 megawatt capacity, making it larger than any solar farm currently operating in Europe.[1] Botley West now has to pass through a complicated and drawn-out approvals process, with a final decision by the UK government not due before 2025.

Fields proposed to be used for solar PV in the central part of the development, just south of Blenheim Palace, north-west of Oxford. From the north to the south of this portion of the solar farm is about 5 km.

The farm will connect directly into the very high voltage transmission network (‘the National Grid’) at a newly built substation just west of Oxford. I think this will be one of the first times any solar development has fed directly into the National Grid, rather than into the lower voltage networks of the local electricity distribution companies.

This is a huge proposal, covering 1,400 hectares (14 sq km, 5.4 sq miles) of mostly agricultural land in Oxford’s ‘Green Belt’ a ring around the city intended to be kept free of new buildings and other developments. A farm of 840 megawatts represents more than 5% of the total installations of solar PV in the UK today and it will generate about one third of one percent of the whole country’s current electricity use. It therefore will cover all the electricity needs of Oxfordshire homes.

The obstacles to the project.

The proposal has elicited strong reactions, mostly unfavourable. The main criticisms include

1.     Resistance to the construction of such an overwhelmingly large project. It will require between 2 and 3 percent of Oxford’s Green Belt, and about half a percent of Oxfordshire’s total land area.[2]

2.     Why does it have to be where it is planned to be?

3.     It is seen as having a negative impact on biodiversity.

4.     And will reduce the amount of land dedicated to arable agriculture.

5.     For local residents, it will affect the appearance of the countryside.

6.     The park will be ultimately owned by a German company. Some people object to the flow of income from the farm flowing to non-UK financiers.


I will look at these points in turn and conclude by suggesting some routes that might help the project secure more support.[3] I should also state that on balance I believe this solar farm would be a very useful part of the UK’s decarbonisation plan.

1.     Why does the project have to be so large?

A large number of smaller farms are being planned, both in Oxfordshire and elsewhere. The recent period of high electricity prices has made solar a relatively cheap way of generating power.

 But almost all of these farms will have to wait many years for connection into the local distribution network operated by Scottish and Southern Networks (SSEN). In many other parts of the country as well as in Oxfordshire, congested lower voltage networks are unable to accept the exports of power from new solar farms. The portion of the electricity distribution infrastructure that brings power to homes and businesses is severely overstretched across much of the UK. Large amounts of new capital, and considerable time, will be needed to upgrade these networks.

Botley West isn’t blocked by this problem. It is sufficiently large to justify the creation of an entirely new high voltage National Grid connection to the main pylon line that runs between the Oxford substation westwards to the Bristol area. The solar farm has to be as large as is planned because only a generator this large can justify the cost of a hugely expensive new substation to tap into this long-distance line.

2.     But why does it have to be in west Oxfordshire, and not somewhere else?

National Grid recently upgraded the Oxford substation at Cowley on the eastern edge of the city, giving substantial extra capacity. This makes possible the Botley West connection a few kilometres away.

I am told by the developers of the Botley West project that National Grid is not able to connect new large scale PV farms elsewhere in the country because the required high voltage capacity is not available. In other parts of the UK, any very large new solar farm will struggle to get a connection before 2031.

Of course this has very serious implications for the pace of the UK’s decarbonisation and the speed of growth of electricity demand as the country seeks to switch heating and transport away from fossil fuels. The lack of any serious policy for achieving the required growth in electricity transmission and distribution capacity will make decarbonisation more difficult than assumed. It’ll block the rapid growth of heat pumps and the development widespread car charging. This issue gets no attention.

Put simply, the Botley West developers have located one of the few areas in the southern half of the UK where a large solar farm can be installed.

3.      Will it have a negative impact on biodiversity?

Intensely farmed agricultural land has truly awful levels of biodiversity. Large, over-cultivated fields with few hedgerows are always terrible for nature. Unfortunately, much of the land that Botley West will use has been farmed excessively and will benefit from a switch to hosting solar panels; ploughing will stop as will the use of fertilisers and pesticides.

The design for the PV farm is not yet complete. So we cannot know exactly what the other benefits of the transition will be. But merely converting ploughed fields to solar helps rebuild some aspects of natural life, particularly if plant life is encouraged around the panels. In addition, the developer promises wide buffer spaces around the individual fields, some woodland planting and biodiversity corridors. Properly done, nature can thrive around solar farms in a way that it is not possible in intensive arable landscapes.  The experience from around the UK and elsewhere is that solar PV can provide a major lift to the quality of the local natural world.

4.     What about the impact of the loss of land for agriculture?

Botley West will extend over about 1,400 hectares. Not all of this land is currently used for agriculture. But let’s assume that it is. If all this area produced wheat, and the land was as productive as the UK average, farmers would get approximately 12,000 tonnes of wheat off this area, with a value of about £2.8m at today’s prices. The value of electricity produced, which will reduce the need to import gas and oil, is approximately 16 times as much.

Perhaps as importantly, average quality agricultural land – such as the area reserved for Botley West – does not produce wheat every year.  It is more likely that the fields would only produce wheat once every three years and, of course, that this crop would generally be used to feed cows, not humans. Botley West is not going to make bread more expensive.

Nevertheless, the loss of agricultural land is still a concern. Imagine for a second that UK decided to use large amounts of field solar, perhaps taking the national capacity up to 200 gigawatts. (It is about 14 gigawatts at the moment).  This would probably generate about 210 terawatt hours, or over two thirds of the UK’s current consumption of electricity. It would require approximately 2% of the UK’s agricultural land to build the solar farms to do this.

Where we can, the country should clearly allocate solar farms to less productive land, particularly outside cereal growing districts. But we should also recognise that some solar will need to be placed in areas of reasonable quality farmland because of the need to secure connections into either the high or low voltage distribution networks.

5.     Affecting the appearance of the countryside

The areas to be devoted to solar panels in the Botley West development are predominantly flat. The panels and the associated infrastructure will be 2.5m high at most. Properly shielded by trees and other vegetation, the solar fields will be largely invisible to local people and to those passing through the area.

Many of the opponents to the Botley West scheme are sceptical about this point. However there are already 25 solar farms in Oxfordshire, and most of them are close to invisible after surrounding trees have grown up. They don’t have significant effects on the views of people in the area.

6.     The proposed park will be owned by a German company

The company that constructs and owns Botley West will be the UK subsidiary of a German company that has constructed solar farms elsewhere in Europe and in Japan. It will pay tax, including business rates, in the UK in exactly the same way as a business owned by a British firm.

Given the scale of the proposed solar farm, probably costing nearly £500m, the German business will also need to raise large amounts of third party capital. Much of this will probably come from UK banks and investors, thus keeping the eventual returns in the country. In the current circumstances perhaps we Britons should be grateful that a German business sees opportunities to help the UK decarbonise in this way.

What should Botley West do to secure local support for the proposal?

The decision whether or not to allow Botley West to be built will be taken by central government, not by local planning officers or district councillors. However favourable local opinions are likely to improve the chances of the project being approved.

The current opposition is widespread and diverse. Local MPs, both Conservative and LibDem, are either explicitly opposed or have expressed deep reservations. Groups such as the Council for the Protection of Rural England (CPRE) have also voiced strong concerns.

CPRE opposes the scheme because, in their eyes, it does not achieve any of the following objectives:

Prioritise the use of brownfield land.
▪ Benefit the local economy.
▪ Be supported and/or owned by local communities.
▪ Bring net benefits to wildlife.
▪ Avoid/minimise loss of productive agricultural land.
▪ Avoid use of designated land such as Areas of Outstanding Natural Beauty and Green Belt, and elsewhere avoid/minimise impact on landscape, tranquillity and cultural Heritage.

This note has tried to contest most of these points, but it is true that the project does not introduce any form of local ownership. So my first suggestion is

·      Allow local people in Oxfordshire to invest in the scheme. Oxford has a very effective group that owns local renewable assets; Low Carbon Hub has built solar farms and hydro-electric power sites in the area and is well placed to act as the platform by which Oxfordshire residents buy shares, or debt instruments, issued by Botley West. In other places, community ownership has transformed attitudes towards renewable schemes that might otherwise have been strongly opposed.

An alternative proposal might be to make yearly dividend payments to all households within 3 km of the farm. This payment could be dependent on the measured output of the farm, giving local people a return based on how much energy is produced.

My second proposal is that the buffer areas around each of the many fields within the development be used to provide other benefits.

·      Create spaces for local agriculture, including allotments and commercial market gardens in the areas around the panels. Local fresh food is in increasing demand and also many people want to become horticulturalists but cannot find land on which they can work. The Botley West development could also provide allotments for all who want to rent space. Of the 1,400 hectares, perhaps 20 hectares could be allocated to community agriculture of one form or another, probably with no loss of output at the solar farm 

A third idea might be to subsidise local residential PV.

·      The developer could develop a package of low cost PV installations that would be offered to all homes within a certain area, allowing local households to benefit directly from PV. A well promoted and designed package offering perhaps 3 kilowatts of solar panels to all homeowners at a highly competitive price might make a big difference to local attitudes towards the development.

Botley West is an enormously ambitious proposal that I believe would help re-start the UK’s stalled decarbonisation process. It is completely understandable that the scheme is creating concern but the country needs schemes like this to provide the green electricity to feed the growing number of electric cars and heat pumps. It would be an extraordinary example of how solar PV could produce cheap electricity on a very large scale with no carbon emissions.

[1] The Francisco Pizarro farm in western Spain opened last year with a capacity of 590 MW. This is currently the biggest PV development in Europe.

[2] Oxfordshire is a county in southern England, of which Oxford is the major city. Oxfordshire has about 600,000 residents in about 270,000 households.

[3] Much of the land that is proposed to be used is owned by a single proprietor. This is the Blenheim estate, the area surrounding Blenheim Palace to the north west of Oxford. I have informal connections with the estate management team and was grateful to them for buying copies of my last book for all their employees. I have no current financial connection with the estate (although I am in grateful receipt of a free annual pass to the grounds!). Nor do I have any connection to the German developer of the site. I am grateful for their response to my questions.