Solar farms in the UK: the complete guide

A solar farm is a ground mounted array of photovoltaic panels that converts sunlight into electricity at scale and feeds it into the grid. It is a working power station rather than a rooftop system, built across open land and measured in megawatts rather than the kilowatts of a domestic installation. The UK has quietly become one of the larger solar markets in Europe, with thousands of ground mounted schemes ranging from a single field feeding a nearby substation to nationally significant projects covering hundreds of hectares. This guide explains what a solar farm is, how one gets built, how the economics work at a high level, and how completed and consented projects change hands as assets.

We broker solar farms, ready to build projects and grid connections between sellers and buyers, so our view of the market is the practical one: what makes a scheme fundable, what makes it saleable, and where value sits along the journey from a field to an operating asset. We are not installers, we do not lend, and we do not give financial advice. What follows is written for landowners weighing whether to host a scheme, for developers and investors trying to understand the wider market, and for anyone who has typed solar farm into a search box and wants a clear, current picture of solar power in the United Kingdom rather than a list of the ten biggest sites.

What is a solar farm and how does it work?

A solar farm is a ground mounted array of photovoltaic modules mounted on steel frames, wired together into strings, and connected through inverters to a transformer that steps the electricity up to grid voltage. Sunlight striking the silicon in each panel releases electrons and produces direct current, the inverters convert that to alternating current, and the transformer delivers it to a substation and onto the local distribution network or the transmission grid. The panels themselves have no moving parts, which is why a solar farm runs with very little intervention once it is energised.

Scale is what separates a solar farm from a rooftop system. Domestic solar is measured in kilowatts and offsets a single building's demand. A solar farm is measured in megawatts, often written as MW for the alternating current capacity that reaches the grid or MWp for the peak direct current rating of the panels themselves. A scheme of a few megawatts sits behind a single field. The largest UK proposals reach several hundred megawatts and occupy land measured in the hundreds of hectares, which is why they are treated as major infrastructure rather than agricultural diversification.

Most modern arrays use fixed tilt mounting, where panels sit at a set angle facing broadly south, though single axis tracking systems that follow the sun through the day are increasingly common on larger sites. Panels are typically raised clear of the ground, which leaves the land beneath and between the rows available for sheep grazing or wildflower planting. Many newer schemes co-locate a battery energy storage system, usually shortened to BESS, so that generation can be stored and released when it is most valuable rather than only when the sun is shining.

How many solar farms does the UK have, and how big is the installed base?

The UK installed base is made up of two distinct populations. The first is rooftop solar on homes, warehouses and commercial buildings, which is large in number but small per installation. The second is ground mounted solar, the solar farms, which are fewer in number but account for a substantial share of total capacity because each one is so much larger. Together they make solar one of the more significant sources of renewable electricity in the country, and the ground mounted portion is the part of the market that trades as investable infrastructure.

Solar farms are spread unevenly across the country, concentrated where the combination of land, grid capacity and planning conditions is favourable. The south and east of England carry a heavy share because irradiation is marginally higher there and the land is often flatter and more open, but ground mounted schemes exist across England, Wales and Scotland. The map of where solar farms sit is really a map of where a grid connection could be secured at a workable cost, which is often the binding constraint rather than sunlight.

The installed base is also growing quickly, and the pipeline of consented and proposed schemes is larger still. Government policy is explicitly aimed at multiplying the amount of solar on the system this decade, which we cover in the outlook section below. For anyone trying to size the market, the useful distinction is between what is already generating, what has planning consent and a grid connection and is therefore ready to build, and what is still working its way through planning and the connection queue. Each of those stages carries a different risk profile and a different value.

Why does solar work in the UK despite the cloudy climate?

The common objection is that Britain is too cloudy for solar to make sense, and the answer is that solar panels respond to daylight rather than to direct sunshine and to heat. Photovoltaic modules generate from diffuse light on an overcast day, just at a lower output than under clear skies. Panels also lose efficiency as they get hotter, so the mild UK climate is not the disadvantage it appears to be. The mechanism that matters is annual irradiation, the total solar energy landing on a square metre across the year, and southern England receives enough of it to make ground mounted solar commercially viable.

The economics work because a solar farm is cheap to run once built. There is no fuel to buy, the panels degrade slowly and predictably, and maintenance is light. A scheme that generates less per panel than one in southern Spain can still be a sound investment in the UK if the capital cost, the grid connection cost and the price the electricity earns line up. That is a question of finance and market design rather than of weather, which is why solar has expanded in a climate that intuition suggests should not support it.

Britain also has a specific structural advantage: demand for clean electricity is rising as heating and transport electrify, and the grid needs generation that can be built quickly. A solar farm can move from consent to generating in a matter of months once its connection is ready, far faster than most other forms of low carbon power. Speed of deployment, rather than raw sunlight, is a large part of why UK solar has become a serious part of the energy mix.

How does a solar farm get built, from land to grid connection?

The starting point is land, usually agricultural land leased from a farmer or landowner on a long option and lease agreement rather than bought outright. A developer looks for a flat or gently sloping site of the right size, close enough to a viable grid connection point, without the environmental or heritage designations that would make consent difficult. Securing land rights is the first real milestone, because without a signed option a developer has nothing to take through planning or into the connection queue.

Planning consent is the second stage, and the route depends on the size of the scheme. Smaller solar farms are decided by the local planning authority under the ordinary town and country planning system. Large solar in England is directed through the Nationally Significant Infrastructure Project regime, known as the NSIP regime, where a scheme above the capacity threshold applies for a Development Consent Order, or DCO, decided by the Secretary of State rather than the local council. The government raised that NSIP threshold for solar from 50MW to 100MW by decision in 2024, according to DESNZ, so a larger band of projects now sits below the national process and is decided locally.

The third stage, and often the hardest, is the grid connection. A project needs a firm agreement from the network operator to accept its power, and connection dates have historically stretched years into the future because the queue of projects seeking to connect grew far faster than the network could absorb. A scheme that has land rights, planning consent and a workable connection date is described as ready to build, or RTB, and reaching that point is what turns a paper project into something a construction team and an investor will commit to. Construction itself is comparatively quick, with panels, mounting, cabling and the substation installed over a period of months before the site is energised and reaches commercial operation, the point known as COD.

How much money does a solar farm make in the UK?

A solar farm earns money by selling the electricity it generates, and there are a few routes to market that determine how predictable that income is. Many projects sign a power purchase agreement, or PPA, a contract under which a buyer agrees to take the output at an agreed price over a number of years, which gives the asset a stable revenue line. Others have competed for a Contract for Difference, or CfD, a government backed mechanism that guarantees a strike price and removes much of the exposure to volatile wholesale power prices. Some sell into the wholesale market directly and accept the price swings in exchange for the upside when power is expensive.

The gross revenue of a scheme is a function of its size, its annual generation and the price it achieves, while the return to an owner is what remains after the cost of the land lease, operations and maintenance, insurance, business rates and any debt service. Because a solar farm has almost no fuel cost and low running costs, a large share of revenue converts into operating income, which is why these assets attract long term institutional capital that values steady, inflation linked cash flows. Adding a co-located BESS can lift income further by allowing the owner to store cheap power and sell it when prices peak.

We deliberately keep this at the level of mechanism rather than quoting a single headline figure, because returns vary enormously with the connection date, the strike price or PPA terms, the cost of capital and the vintage of the panels. What is consistent is the shape of the investment: high upfront cost, long life, low running cost, and revenue that can be made highly predictable through the right contract. That profile is what our economics content examines in more detail, and it is the reason operational solar trades at the yields it does.

Where is the largest solar farm in the UK, and what counts as a big scheme?

The largest UK solar farms are the NSIP scale schemes that go through the Development Consent Order process rather than local planning. Cleve Hill in Kent is the first of this generation to reach operation, a large ground mounted array with co-located storage that set the template for major solar as national infrastructure. It is the reference point most people reach for when they ask where the biggest solar farm in the UK is, though a wave of even larger consented and proposed schemes is following it.

Behind Cleve Hill sit a number of large NSIP scale projects at various stages of consent and construction, including Botley West in Oxfordshire, Mallard Pass on the Lincolnshire and Rutland border, Longfield in Essex, Springwell and Tillbridge in Lincolnshire. These are the schemes that dominate headlines and consultations because of their footprint, and they illustrate how far the top end of the UK market has scaled: projects that a decade ago would have been unthinkable in size are now working their way through the national planning system.

It is worth keeping perspective on what counts as large. The overwhelming majority of solar farms are far smaller than these flagship schemes, single sites of a few megawatts to a few tens of megawatts that were consented locally and connected quietly. Those smaller schemes are the bulk of the operating fleet and the bulk of what trades between owners. The giant projects define the ceiling of the market and the policy debate, but they are the exception rather than the norm.

How do solar farms trade as assets?

A solar farm is a long lived infrastructure asset, and like any such asset it is bought and sold. Two broad categories change hands. Operational solar farms, already generating and earning, trade on the strength of their revenue contracts and their remaining life, valued much as any income producing asset would be. Ready to build projects, which hold land rights, planning consent and a grid connection but have not yet been constructed, trade on the value of that consented, connectable position, which a buyer intends to build out or hold.

A large amount of this activity happens off market rather than through open listings. Owners of operating fleets, funds rebalancing portfolios, developers monetising a consented project and landowners with an option they no longer wish to pursue often prefer a discreet, matched sale to a known buyer over a public marketing process. This is where our work sits: we broker solar farms, ready to build projects and grid connections between sellers and buyers, quietly and directly, so that a seller reaches the right counterparty without advertising the asset to the whole market and a buyer sees opportunities that are never publicly listed.

For a seller, the questions that determine value are the strength and length of the revenue contract for an operating asset, or the firmness of the planning consent and connection date for an RTB project. For a buyer, diligence focuses on the same points plus the condition of the equipment, the terms of the land lease, and any planning conditions attached to the consent. Matching the right project to the right buyer is less about a headline price than about a buyer whose mandate genuinely fits the asset, which is the part of a transaction where a broker earns their place.

What are the land use and community concerns around solar farms?

The most common objection to a solar farm is that it takes farmland out of food production. In practice most schemes are built on lower grade agricultural land, are consented for a defined period after which the land can be returned to farming, and occupy a small fraction of total farmland even at the scale now being planned. The food security debate is real and features heavily in local consultations, but the areas involved are modest against the national picture, and planning policy steers large schemes away from the best and most versatile land.

Land under and around a solar farm does not have to be lost to agriculture at all. Agrivoltaics, the practice of combining solar generation with farming on the same land, allows sheep to graze between and beneath the rows, and many schemes maintain active grazing throughout their life. This dual use softens the food versus energy tension and is increasingly written into how projects are designed and presented to communities.

Solar farms can also deliver environmental gains rather than only occupying space. The land beneath the panels is typically taken out of intensive arable use and managed for wildflowers, hedgerows and habitat, which supports the biodiversity net gain that planning now requires of major development. Visual impact, glint and glare, and the loss of open views remain genuine community concerns that are handled through screening, layout and consultation, but a well designed scheme can leave a site richer in wildlife than the monoculture it replaced.

What does the 2030 outlook mean for UK solar farms?

Government policy has put a firm number on its ambition. The Clean Power 2030 Action Plan, published in December 2024, targets 45 to 47GW of solar capacity by 2030, according to DESNZ, which is roughly a tripling of installed capacity from the point the plan was published. That is a deliberate signal to landowners, developers and investors that solar is central to the plan for a decarbonised grid, and it underpins the scale of the pipeline now moving through planning and the connection queue.

Reaching that target depends on the grid catching up with the ambition, and the machinery for that is now being rebuilt. The connection queue had grown past 700GW of projects before reform, several times what the system needs, according to NESO in 2024, which is why connection dates had drifted so far out. The reforms now being implemented reorder the queue around readiness rather than the date a project first applied, which should move genuine, deliverable solar farms towards firm connection dates faster. We cover that policy machinery in detail in our pipeline and policy guide.

For anyone holding or considering a solar asset, the outlook is one of strong structural demand set against real delivery constraints. The direction of travel is clear and well supported by policy, but the value of a given project increasingly turns on where it sits in the queue and how firm its connection is. That is precisely why the ready to build and operational stages of the market are so actively traded, and why the difference between a consented project with a firm connection date and one still waiting in the queue is now one of the sharpest distinctions in the whole market.

How do Contracts for Difference and PPAs underpin solar power revenue?

Most UK solar farms sell their electricity through one of three routes, and the route shapes the asset. A Contract for Difference, awarded through the government scheme's periodic allocation rounds, fixes a strike price for eligible renewable energy generation, giving a power plant revenue certainty that lenders and buyers prize. A power purchase agreement does something similar bilaterally: a corporate or utility contracts to buy the solar power for a term at agreed pricing. And merchant exposure, selling into the wholesale market, offers the highest potential income with the least certainty.

The revenue route matters at national scale too. Contracted revenue is what lets developers finance construction and grow the UK's installed capacity toward the Clean Power 2030 target of 45 to 47GW, and it is what turns a field of panels into an investable piece of renewable energy infrastructure. When solar farms trade, the remaining term and price of these contracts sit near the centre of every valuation, which is why two farms of identical size and age can be worth very different amounts.