How to finance commercial solar panels

Plenty of businesses stall on solar not because the numbers don’t work, but because they don’t want to drop £50,000, £100,000 or considerably more of capital onto a roof in one go.

This is certainly an understandable position; a solar PV system may offer an attractive long-term return, but it has to compete with everything else a business could do with that money. That may include new machinery, recruitment, acquisitions, stock, property improvements or simply keeping more cash in reserve.

The important thing to keep in mind though is that paying for commercial solar doesn’t necessarily mean writing one large cheque upfront.

There are three main routes businesses tend to consider: buying the system outright, using asset finance to spread the cost, or installing it under a Power Purchase Agreement (PPA), where somebody else owns the equipment and you buy the electricity it generates.

Each approach makes sense in its own way. The right choice for your business depends less on which solar panels you install, and more on your cash position, tax position, attitude to ownership, cost of finance and how long you expect to occupy the building.

The first step is therefore to separate two questions:

Does solar make financial sense for this site?

and

What is the best way for us to pay for it?

1. Buy it outright: capital purchase

The simplest model is also the easiest to understand. You pay for the system, it is installed on your property and you own it from day one.

There are no monthly finance payments and there’s no third-party investor taking a share of the value generated by the system. Subject to the assumptions in your financial model, the savings generated by reducing grid electricity purchases belong to you.

For a business with sufficient capital available, this will usually produce the strongest lifetime financial return because there is no interest or PPA margin to fund.

If your solar installation costs £100,000, however, the obvious downside is that £100,000 has to come from somewhere.

That means the question to ask when considering a solar purchase isn’t “Can we afford the solar panels?”, but rather “Is putting this capital into solar the best use of it?”

If the same £100,000 could generate a much larger return by increasing production capacity, opening a new location or buying another company, solar may not be the first investment you make.

If the cash would otherwise remain in the bank earning a much smaller return than the solar project is expected to deliver, the calculation can look very different.

The tax position can strengthen the case for buying

Capital allowances are another important part of the outright-purchase calculation.

Solar panels are specifically treated by HMRC as special-rate plant and machinery. HMRC guidance also confirms that solar expenditure can qualify for the Annual Investment Allowance (AIA), subject to the normal eligibility rules and available allowance. The current AIA limit is £1 million per accounting period.

That means a qualifying business can potentially deduct eligible expenditure from taxable profits rather than waiting for the cost to be relieved gradually over many years; the exact cash value depends on the company’s tax position.

For the 2026 Corporation Tax year, the main rate is 25% for companies with profits above £250,000, while companies with profits below £50,000 are subject to the 19% small profits rate, with marginal relief applying between those thresholds.

So the often-used example that a £100,000 qualifying investment could reduce Corporation Tax by £25,000 is possible for a company paying the 25% rate and able to make full use of the allowance. It isn’t a universal £25,000 rebate.

The timing of the expenditure, the amount of AIA already used elsewhere in the business, group-company rules and the company’s taxable profit all matter, so the tax calculation should always be confirmed with your accountant.

Ownership gives you the full upside

The other big advantage is straightforward: once you’ve bought the system, you own the asset.

If electricity prices rise, the value of the electricity you generate and consume on site can rise too.

Once the system has reached its modelled payback point, it can continue generating electricity for years afterwards. Commercial solar modules are designed as long-life assets, so the period after payback is often an important part of the total investment case.

Ownership also gives you more control over decisions such as maintenance providers, system modifications, battery storage additions and future integration with EV charging or other electrical infrastructure.

But ownership also means responsibility

Buying a system means taking responsibility for the asset. Solar may not require constant intervention, but your commercial system should still be monitored and maintained appropriately. Inverters, isolators, electrical components, mounting systems and the condition of the array all need to be considered over its operating life.

Those costs should already form part of the financial model. Some make the mistake of considering 20 or 25 years of savings with an outright purchase, without taking into account that the system will require inspecting, maintaining or even replacing.

What happens if you don’t own the building?

Buying outright is particularly straightforward for an owner-occupier, but for a tenant, there are more questions.

You’ll need to consider questions like: How long is left on the lease? Does the landlord consent to the installation? Who owns the system at the end of the tenancy? And what happens if the business relocates?

A 20-plus-year solar asset and a commercial property lease with only five years remaining are obviously a less comfortable match – unless the legal arrangements deal with that difference. The property position should therefore be checked before committing capital.

The option is best suited to: businesses with capital available, a strong tax position, confidence in the site’s long-term use and a preference for maximum ownership and lifetime return.

2. Spread the cost: asset finance

The second route is to finance the asset rather than pay the full cost upfront.

This can provide a useful middle ground between a capital purchase and a PPA.

The business can retain the long-term benefits of ownership while avoiding a major immediate hit to working capital.

Instead of paying £100,000 today, for example, the business might spread the expenditure across an agreed finance term.

The exact structure can take different forms, including hire purchase, finance arrangements and leases, so it is important not to treat “solar finance” as one generic product.

Terms, deposits, interest rates, security requirements and ownership arrangements vary between lenders and borrowers. Current commercial solar finance guides commonly show multi-year asset-finance terms rather than one fixed industry standard.

The important comparison is repayment versus saving

One of the most useful ways to assess asset finance is to put the finance repayment alongside the expected electricity saving.

Imagine a system is modelled to save the business £2,000 per month in electricity costs. If financing the project costs £2,100 per month, the effective additional cash-flow burden is very different from a project costing £2,100 per month that produces no operational saving.

Likewise, if the modelled saving is £2,500 and the finance payment is £2,000, the project could potentially improve monthly cash flow while it is still being financed.

That isn’t guaranteed of course, it depends on system performance, electricity consumption, electricity tariffs, finance rates and the exact repayment structure. But this is why simply looking at the total interest charge can be misleading.

The solar asset is doing something during the repayment period: it is generating electricity and reducing grid purchases. The betterl model compares the two cash flows month by month.

Finance lets you preserve capital for the core business

This can be particularly valuable for growing companies. A manufacturer might have £150,000 available but need that money to fund equipment, stock or expansion.

The decision isn’t necessarily between a £150,000 solar system or no solar system.

It could instead be a case of use £150,000 of cash to buy solar, or else finance the solar, retain most of the cash and use that capital elsewhere.

If the other use of the money produces a stronger return than the cost of finance, borrowing to fund solar can be entirely rational even though paying cash would produce the lower total solar cost in isolation.

That is why the cheapest financing route isn’t automatically the best capital-allocation decision for the business.

Don’t assume all asset finance has the same tax treatment

The phrase “asset finance” covers different legal arrangements.

Under hire purchase, HMRC guidance allows qualifying plant and machinery to be treated as owned by the person acquiring it for capital-allowance purposes where the agreement provides for them to become the owner. The givernment also states that, when an asset bought under hire purchase starts being used, AIA can potentially be claimed on qualifying payments due under the contract, excluding interest.

Leasing can work differently. HMRC notes that capital allowances generally belong to the legal owner of plant and machinery, although there are exceptions and additional rules, including for hire purchase and certain long-funding leases.

Accounting treatment has its own rules as well. So the upshot is don’t choose between hire purchase, a finance lease or another structure based on a one-line statement about tax relief; get your accountant to look at the actual agreement.

The difference could affect who claims allowances, how the liability appears in the accounts and the real post-tax cost of the finance.

What happens when the finance term ends?

This is where asset finance can become particularly attractive. Remember that while the finance payments eventually stop, the solar panels don’t.

If the system is expected to operate for 25 years or more and the finance term covers only part of that period, the remaining years can provide a long runway of electricity savings without the original finance repayment.

Let’s say a business finances a system over seven years. During those seven years, the solar savings offset some or potentially much of the finance payment, and at the end of year seven, the borrowing is cleared.

THowever the asset could still have many years of generation ahead of it. So the lifetime return therefore shouldn’t be judged solely by looking at the first few years.

Check early-repayment and ownership terms

Businesses should also understand what happens if circumstances change. Consider:

• Can the finance be settled early?
• What happens if the building is sold?
• Can the asset be transferred?
• Is there a final balloon payment?
• When does legal ownership transfer?
• Are there arrangement fees?
• What security or guarantees does the lender require?

These details may seem secondary when everybody is focused on solar generation figures, but they can make a material difference to how flexible the arrangement is later.

This approach is best suited to businesses that want the long-term economics of ownership but would rather preserve working capital and spread the cost over several years.

3. Pay nothing up front: Power Purchase Agreement

The third route is very different. Under an onsite solar Power Purchase Agreement, or PPA, a third-party provider funds the solar installation on your building.

It might sound too good to be true. The key thing to know is that the provider owns the system. Rather than buying the equipment, your business agrees to buy the electricity the system generates at a contractually agreed price. Meanwhile, the provider typically takes responsibility for monitoring and maintaining it

The attraction is easy to understand, and this approach removes the large capital requirement entirely.

Your roof starts generating solar electricity without your business having to find the capital to build the system – and instead of paying the grid supplier for every unit of electricity you use, you buy some of your electricity from the solar system at the agreed PPA tariff.

Current UK commercial PPA market guides commonly describe long contract terms, often around 15 to 25 years, with pricing negotiated according to project size, credit quality, consumption and other factors. Published 2026 examples show considerable variation in the starting pence-per-kWh rate, reinforcing why the actual project should be priced rather than relying on a generic national figure.

Why would somebody install solar on your roof for free?

Clearly there has to be an upside for the provider. The investor funds the capital cost because they receive an income stream from the electricity generated by the system.

Your business benefits because the agreed solar electricity price should be attractive compared with the relevant grid electricity cost.

The provider benefits because the PPA gives them a long-term customer for the output of the asset. Both sides therefore need the installation to produce enough electricity, for long enough, for the arrangement to make commercial sense.

That’s why PPAs are particularly suited to buildings with high and predictable daytime electricity consumption.

A large warehouse, manufacturing facility, distribution centre, leisure facility or public-sector building with significant daytime demand can be a much more attractive PPA proposition than a property that uses very little electricity while the panels are generating.

PPAs remove capex, not cost

This distinction is important. A PPA is often marketed as “free solar”, but of course that would be too good to be true.

You aren’t paying for the panels as a capital asset, but rather for the electricity they generate.

The better description is therefore zero-upfront-capital solar, not free electricity.

If your PPA rate is below the alternative grid cost, you save money on every eligible unit consumed under the agreement. But because the investor has paid for the asset and needs a return on that investment, your total lifetime saving will generally be lower than if you had funded the installation yourself without financing costs.

In return, you have kept your capital – that’s the trade.

Who maintains the system?

One of the strongest practical benefits of a PPA is that maintenance responsibility normally sits with the system owner under the contract.

Because the provider needs the array to generate electricity in order to earn revenue, they have a financial incentive to monitor performance and resolve problems.

For organisations that don’t want another asset to manage, this can be as important as the lack of capex.

A public-sector body, property operator or large corporate organisation may prefer predictable energy costs without wanting responsibility for managing the solar equipment itself.

The contract should, however, state clearly who is responsible for monitoring, planned maintenance, equipment failures, roof access and reinstatement.

You should be sure that “no maintenance responsibility” is guaranteed, not implied, before proceeding on that assumption.

Understand the PPA escalator

Some PPAs use a fixed tariff for the whole contract. Others allow the solar electricity price to rise each year using a fixed percentage or an index-linked mechanism. This is usually called an escalator.

That can materially change the economics over a 15-, 20- or 25-year agreement.

A tariff that looks extremely competitive in year one may look less impressive many years later if it rises faster than the grid price it is supposed to beat.

Current UK PPA market examples include both fixed and escalating structures, with some published indicative terms using fixed-percentage or RPI-linked increases.

Don’t therefore compare PPA offers based on the year-one pence-per-kWh figure alone, but model the entire contract.

You’ll want to know how much electricity the system is expected to generate, how much you are likely to consume, how the PPA tariff changes and how the projected total cost compares with plausible grid-price scenarios.

What happens if the grid price falls?

This is an important risk to understand.

If your PPA tariff escalates every year but grid electricity becomes cheaper, the saving between the two can narrow.

In a sufficiently extreme scenario, the contracted solar rate could potentially become unattractive relative to the alternative electricity price. That is why the price-review and protection mechanisms in the contract matter.

Rather than assuming a generic “grid parity clause” will always exist, you’ll want to know exactly what happens if grid prices fall below, or close to, the PPA price. Ask yourself:

• How is the comparison calculated?
• Which element of the grid tariff is used?
• How often is the comparison reviewed?
• What happens if the PPA rate is no longer competitive?

A 20-year PPA is also a property decision

One of the most overlooked aspects of a solar PPA is that it isn’t only an energy contract. Remember that it places somebody else’s asset on your building for a long period. That creates property questions, as well as energy questions.

If you own the building, what happens if you sell it in ten years?

Can the PPA transfer to the new owner?

Would a buyer need to accept the agreement?

If you’re a tenant, does the lease run for at least as long as the PPA?

Will the landlord grant the necessary rights?

What happens at lease expiry?

And what if the roof needs replacing halfway through the PPA term?

None of these are dealbreakers for a PPA, but they are reasons to at least have your property and legal teams involved before signing one. A great electricity price doesn’t compensate for a contract that becomes a problem during a property transaction.

Don’t choose the finance before you’ve designed the system

In deciding between the three routes, it’s important to step back and not get ahead of yourself

Before deciding whether to buy, finance or enter a PPA, you need to know whether the underlying system actually works commercially. Financing doesn’t make a poor solar project good.

That means you should understand the site’s electricity consumption, when that electricity is used, roof area, orientation, shading, electrical infrastructure, expected generation and likely level of self-consumption.

A PPA on an oversized system isn’t automatically attractive, and asset finance on a poorly matched array isn’t automatically sensible. Nor does paying cash rescue a project with weak generation economics.

Self-consumption has a big influence on the numbers

Commercial solar typically creates its greatest financial value when the business can use the generated electricity on site.

If a factory is consuming significant electricity throughout the middle of the day, a large proportion of its solar output may be used directly within the building. That replaces electricity that would otherwise have been imported. If a building is largely empty during daylight hours, more generation may be exported instead.

Export still has value, but it may have a different financial value from electricity that offsets imported consumption. That means two identical 200 kWp systems can have very different commercial outcomes depending on the buildings underneath them.

It also affects financing; a lender or PPA provider assessing a project will want confidence that the site’s consumption and operating profile support the assumptions being used.

What about battery storage?

Battery storage is another factor that can change the financial model. A battery can potentially allow a business to retain more solar generation for use later rather than exporting it immediately, as well as supporting wider energy-management strategies.

But a battery adds capital cost, and that additional investment needs its own business case.

If the site’s daytime electricity consumption already absorbs almost all solar generation, a battery installed purely to increase solar self-consumption may produce less value than it would on a site exporting a significant amount of electricity during the day. Solar and battery storage should therefore be modelled together where appropriate, but not treated as an automatic package.

The same applies to EV charging. If a business expects to electrify a vehicle fleet over the next few years, future charging demand may materially alter the optimum solar-system size and the value of the electricity it generates.

Compare cash flow, not just headline payback

This is where financing comparisons become much more useful. Suppose three proposals are put in front of the board.

The first says:

Capital purchase: pay £150,000 now.

The second says:

Asset finance: pay a fixed amount every month for several years.

The third says:

PPA: pay no capital cost, then buy solar electricity under a long-term contract.

Looking only at payback isn’t enough, as each option creates a totally different cash-flow profile.

The outright purchase has the biggest negative cash movement at the start but potentially the strongest savings later.

Asset finance reduces the initial cash requirement but introduces finance repayments.

A PPA may require little or no capital but gives some of the project’s economic value to the third-party investor.

A useful comparison therefore models the cumulative position across the whole project life.

That lets you see not just “payback in X years” but when each option becomes cash-positive, what the maximum capital exposure is and how much total benefit remains after financing costs.

Tax shouldn’t be allowed to distort the decision

Capital allowances can materially improve a solar project’s economics. But they shouldn’t turn a weak project into something that appears strong simply because somebody describes the tax benefit as free money.

Tax relief reduces taxable profit. Its actual value depends on the business paying tax in the first place and on the relevant allowances being available.

If the company is loss-making, has already used substantial allowances or is part of a group with a more complicated tax position, the practical benefit and timing may be different.

The same applies when financing the installation. The contract structure can alter who owns the asset for tax purposes and who is entitled to relevant allowances. HMRC explicitly notes that ownership is central to capital-allowance entitlement, subject to specific rules for structures such as hire purchase and long-funding leases.

Treat the tax benefit as part of the financial model, then have the assumptions checked professionally.

What if you’re planning to move?

Your expected occupation period should influence the finance choice.

If you own a manufacturing facility that is central to the business and expect to operate from it for another 20 years, long-term solar investment is comparatively straightforward.

If your lease expires in six years and relocation is a real possibility, the decision becomes more complicated. An outright installation may still add value to the sale, but you need to understand what happens to the asset.

Asset finance needs to be considered alongside the lease term. A long PPA needs clear transfer or termination provisions.

The more uncertain the property position, the more important contract flexibility becomes. This is one reason financing shouldn’t be discussed independently of the building itself.

So which way should you finance commercial solar?

There genuinely isn’t one answer that works for every business.

The broad trade-offs are relatively simple. Buying outright generally gives the business the greatest level of ownership and avoids external financing costs, but requires the largest immediate capital commitment.

Asset finance lets the business retain capital and spread the cost while still pursuing ownership, but finance charges reduce the lifetime return compared with an equivalent cash purchase.

A PPA can remove most or all of the upfront capital requirement and shift much of the operational responsibility to the provider, but the provider receives part of the economic value of the system in return.

The real choice comes down to what the business values most: capital preservation, maximum lifetime return, ownership, predictable monthly cash flow or minimal operational involvement.

Questions worth asking before choosing

Before signing any funding agreement, make sure the numbers answer the practical questions behind it:

• What does the system cost and how much electricity is it realistically expected to generate?
• How much of that electricity will we actually use on site?
• What are the expected first-year and lifetime savings?
• What assumptions have been made about future electricity prices?
• What happens if generation is lower than forecast?
• Who owns the equipment during and after the agreement?
• Who receives the tax allowances?
• What maintenance costs and responsibilities sit with us?
• What happens if we sell the building or leave the site?
• Can the agreement be repaid, transferred or bought out early?
• If it is a PPA, how does the tariff change over time?
• What happens at the end of the contract?

The finance proposal should make those answers clearer, not obscure them behind one attractive monthly figure.

The cheapest option isn’t necessarily the right one

If all you care about is maximising the financial return from the solar system itself and you have sufficient cash available, outright ownership is difficult to beat.

But businesses don’t allocate capital in isolation. A £250,000 solar system might offer a strong return while the same £250,000 invested into production equipment offers an even stronger one.

Financing the solar and buying the production equipment could therefore produce a better overall outcome than choosing one project over the other.

Likewise, an organisation may willingly accept the lower lifetime financial return of a PPA because avoiding capital expenditure and maintenance responsibility is more important.

The best comparison uses your own numbers

Generic examples are useful for explaining how commercial solar finance works, but they can only take you so far.

The difference between a good capital purchase, asset-finance agreement and PPA depends on the actual building underneath the panels.

A useful model should start with your electricity consumption and tariff, then assess the site’s realistic solar-generation potential.

From there, the same system can be run through each funding structure.

That lets you compare:

Capital purchase: initial expenditure, tax position, annual savings, payback and lifetime return.

Asset finance: deposit, finance term, repayments, electricity savings, tax treatment and the point at which the finance ends.

PPA: upfront expenditure, starting energy tariff, escalation mechanism, projected annual saving, contract length, maintenance responsibility and end-of-term arrangements.

If you put those three next to each other, the decision becomes much easier.

The short version

There are several ways to make a commercial solar project work without treating it as a simple choice between spending a large amount of cash today or doing nothing.

If you have the capital, expect to remain at the site for the long term and want the strongest possible ownership position, buying outright can offer an attractive lifetime return.

If you want to own the system but would rather preserve cash for the rest of the business, asset finance can spread the investment while the panels are already generating electricity and reducing grid consumption.

If keeping capital expenditure to a minimum and transferring much of the operational responsibility are the priorities, a Power Purchase Agreement can deliver solar without purchasing the system yourself.

None of them is automatically best. And the financing decision should come after the most important question has been answered: is this a well-designed solar project with a strong business case for this particular site?

Hybrid Asset Solutions can model the different funding routes alongside the site’s expected generation and electricity consumption, allowing you to compare the upfront cost, monthly cash flow and long-term return side by side before deciding how – or whether – you want to fund the project.

Tax treatment depends on individual circumstances and the structure of the transaction. Businesses should confirm capital-allowance and accounting treatment with their accountant or tax adviser before proceeding.