MCS Certified
Microgeneration Certification Scheme
NAPIT Approved
Electrical Competency
RECC Member
Consumer Protection
ISO 45001
Health & Safety Management
ISO 9001
Quality Management
ISO 14001
Environmental Management
4.9 / 5
500+ verified reviews
Power Purchase Agreements for Commercial Solar: Complete Guide
Everything your business needs to know about Power Purchase Agreements for solar energy. Zero upfront cost, immediate bill savings, and how PPAs compare to outright purchase.
PPA in Brief
A Power Purchase Agreement allows your business to benefit from on-site solar panels with zero upfront investment. A third party owns and maintains the system on your roof, and you simply buy the electricity at a 20-30% discount to grid prices. Typical contract terms are 20-25 years.
What Is a Power Purchase Agreement?
A Power Purchase Agreement, commonly known as a PPA, is a contractual arrangement where a third-party investor funds the installation of a solar panel system on your commercial property. The investor retains ownership of the system throughout the contract term, and your business agrees to purchase the electricity generated at a pre-agreed unit rate that is lower than the standard grid electricity price.
The concept is straightforward: instead of investing your own capital in solar panels, an external party makes the investment and you benefit from cheaper electricity. The investor earns a return over the contract term through the electricity payments you make. It is a win-win arrangement that has become increasingly popular among UK businesses, particularly those that want the benefits of solar energy without the upfront capital commitment.
PPAs have been widely used for large-scale renewable energy projects for decades and have become increasingly accessible for mid-sized commercial installations. In the UK, PPAs are now available for commercial solar systems as small as 50kW, though the most common size range for PPA-funded installations is 100kW to 1MW. The larger the system, the more attractive the terms tend to be for both parties.
It is important to distinguish between a solar PPA and a sleeved or virtual PPA, which involves purchasing renewable electricity from an off-site generator through the grid. This guide focuses on on-site solar PPAs, where the panels are physically installed on your property and the electricity is consumed directly by your business.
How a Solar PPA Works
The process of establishing a solar PPA follows a well-defined sequence that protects both parties and ensures the system is designed to maximise your electricity savings.
Site Assessment and System Design
The PPA provider conducts a thorough site survey to assess your roof, electrical infrastructure, and energy consumption patterns. They design a system optimised for your property and usage profile, typically maximising self-consumption to deliver the greatest savings.
PPA Terms and Contract
The provider presents PPA terms including the unit rate for electricity (typically 20-30% below grid price), contract duration (usually 20-25 years), annual price escalation mechanism, maintenance obligations, and end-of-contract options. You review and negotiate these terms before signing.
Installation and Commissioning
The PPA provider manages the entire installation process, including G99 grid connection where required. You provide roof access and cooperation but bear no installation costs. The system is commissioned and begins generating electricity for your business.
Ongoing Operation
Once operational, you consume the solar electricity generated during daylight hours and pay the PPA rate for each kWh consumed. Any electricity not consumed is exported to the grid by the PPA provider. You continue to buy grid electricity for consumption above what the solar system provides and during non-generation hours.
End of Contract
At the end of the PPA term, you typically have three options: purchase the system at fair market value (often very low after 20-25 years), extend the PPA at revised terms, or have the system removed at the provider's expense.
Typical PPA Terms
While PPA terms vary between providers and are negotiable, the following represents the typical range of terms you can expect for a commercial solar PPA in the UK in 2026.
| Term | Typical Range | Notes |
|---|---|---|
| Contract length | 20-25 years | Some providers offer 15-year terms |
| Discount to grid price | 20-30% | Higher discounts for larger systems |
| Annual price escalation | 1-3% or RPI-linked | Fixed escalation preferred for predictability |
| Minimum system size | 50-100 kW | Varies by provider |
| Maintenance | Included | Full O&M responsibility with the provider |
| Performance guarantee | 85-90% | Minimum generation guarantee typical |
| End-of-term options | Purchase / Extend / Remove | Buyout price typically nominal after 20+ years |
The annual price escalation clause is one of the most important terms to negotiate. A fixed escalation of 1-2% per year provides cost certainty and typically keeps the PPA rate well below grid prices, which have historically risen faster than this. RPI-linked escalation tracks inflation but introduces uncertainty. Some providers offer fixed-price PPAs with no annual increase, though the initial rate will be higher to compensate.
We recommend having PPA contracts reviewed by a commercial solicitor before signing, as the long-term nature of these agreements means the terms will affect your business for decades. Pay particular attention to the termination clauses, transfer provisions, and any obligations that fall on the property occupier during the contract term.
PPA vs Outright Purchase: Pros and Cons
Both PPAs and outright purchase have distinct advantages. The right choice depends on your business's financial position, risk appetite, and strategic priorities.
PPA Advantages
- ✓Zero upfront capital investment required
- ✓Immediate electricity bill savings from day one
- ✓No maintenance costs or operational responsibility
- ✓No technology risk as provider manages the system
- ✓Preserves working capital for core business investment
- ✓Predictable energy costs with known escalation rate
- ✓Off-balance sheet treatment possible under certain structures
Outright Purchase Advantages
- ✓Highest total financial returns over system lifetime
- ✓Immediate tax relief through AIA (25% saving)
- ✓100% of savings and export income retained
- ✓No long-term contractual commitments
- ✓Full ownership and flexibility from day one
- ✓Adds asset value to property
- ✓Payback typically 4-6 years with tax relief
In purely financial terms, outright purchase delivers significantly higher lifetime returns. A business that purchases a 100kW system for £95,000 (effective cost £71,250 after AIA) will recoup the investment in approximately 4.5 years and then benefit from free electricity for the remaining 20+ years of the system life. Under a PPA, the business saves money from day one but continues paying for the electricity throughout the contract term, with total savings over 25 years being approximately 40-50% less than outright ownership.
However, financial return is not the only consideration. For businesses that need to preserve cash for growth, cannot access capital, or prefer to avoid taking on asset ownership and maintenance responsibility, a PPA provides an excellent risk-free route to lower energy costs and reduced carbon emissions. The best choice is the one that aligns with your business strategy and financial capacity.
Typical PPA Savings
The savings from a solar PPA depend on the discount rate offered, the system size relative to your consumption, and how much of the solar generation you consume directly. The following examples illustrate typical savings for different business sizes.
| Scenario | Annual Electricity Bill | System Size | Annual PPA Saving | Saving % |
|---|---|---|---|---|
| Small office / retail | £15,000 | 50 kW | £3,200 - £4,500 | 21-30% |
| Medium commercial | £35,000 | 100 kW | £6,500 - £9,000 | 19-26% |
| Large warehouse | £80,000 | 250 kW | £16,000 - £24,000 | 20-30% |
These figures represent the saving compared to purchasing all electricity from the grid. The actual saving depends on your current electricity tariff, the PPA rate offered, and the proportion of solar generation you consume directly. Businesses with high daytime electricity consumption achieve the greatest savings, as more of the solar generation displaces expensive grid electricity.
To explore whether a PPA is right for your business and to compare the financial outcomes with outright purchase, contact our team for a detailed assessment. We can model both scenarios based on your actual electricity consumption data and provide a clear comparison to support your decision.
Who Are PPAs Best Suited For?
While any business can benefit from a solar PPA, the model is particularly well-suited to certain types of organisations and situations.
Ideal PPA Candidates
- ✓Businesses without available capital for solar investment
- ✓Organisations that prefer operational expenditure to capital expenditure
- ✓Public sector and non-profit organisations that cannot claim capital allowances
- ✓Tenants with long lease terms who want solar but cannot invest in the landlord's building
- ✓Businesses focused on reducing carbon emissions without capital risk
- ✓Schools and healthcare facilities with limited budgets
Better Suited to Outright Purchase
- ✓Businesses with available capital and strong cash flow
- ✓Companies paying corporation tax who can claim AIA
- ✓Property owners planning to hold the building long-term
- ✓Businesses wanting maximum long-term financial returns
- ✓Organisations that prefer full ownership and control
- ✓Warehouse and manufacturing businesses with large roof areas
For a complete picture of the financial options available for your commercial solar project, see our commercial solar cost guide, which covers all financing routes including outright purchase, PPA, and asset finance in detail.
Frequently Asked Questions
A Power Purchase Agreement (PPA) is a long-term contract where a third-party investor finances, installs, owns, and maintains a solar panel system on your commercial property. You agree to purchase the electricity generated by the system at a pre-agreed rate, typically 20-30% below your current grid electricity price. You pay nothing upfront and benefit from reduced electricity costs from day one, while the investor earns a return through the electricity sales over the contract term.
Solar PPA contracts typically last 20 to 25 years, reflecting the long operational life of solar panels. Some providers offer shorter terms of 15 years, though these may come with higher per-unit electricity rates. At the end of the contract, you usually have the option to purchase the system at a fair market value (often nominal given the age of the equipment), extend the agreement, or have the system removed at the provider PPA cost.
If you sell the property during the PPA term, the agreement typically transfers to the new owner or tenant as part of the property transaction. This is usually handled through a novation agreement. The PPA can actually add value to your property, as the new occupier inherits discounted electricity from day one. However, it is important that the PPA terms are disclosed during the sale process and that the buyer agrees to assume the contract. Some PPA providers offer early termination clauses, though these may involve buyout costs.
Most PPA contracts include an option to purchase the solar system at predetermined intervals, typically after 5, 7, or 10 years. The buyout price is usually set at a declining rate based on the remaining contract term and the depreciated value of the system. Purchasing the system during the PPA term can be advantageous if electricity prices have risen significantly, as you would then capture 100% of the savings and export income for the remainder of the system lifespan.
Under a PPA, the system owner (the PPA provider or investor) is responsible for all maintenance, repairs, and monitoring throughout the contract term. This includes routine inspections, cleaning, inverter replacement, and any fault repairs. You bear no maintenance costs or responsibility. The PPA provider is incentivised to maintain the system at peak performance, as their revenue depends on the electricity generated.
The best option depends on your business circumstances. Outright purchase delivers higher total savings over the system lifetime and provides immediate tax relief through the Annual Investment Allowance. A PPA is better suited to businesses that cannot or prefer not to invest capital upfront, want guaranteed savings with zero risk, or do not have a tax position to benefit from capital allowances. Our team can model both scenarios for your specific situation to help you make an informed decision.
Ready to Cut Your Business Energy Costs?
Get a free, no-obligation site survey and quotation for your commercial property. Our MCS certified team will assess your building and provide a detailed proposal within 5 working days.
Prefer to speak to someone?
01279 295630