Comparison · Solar lease vs PPA

Solar lease vs PPA — UK commercial 2026

Solar lease and PPA are both structures where you don't own the system. But they differ fundamentally on how you pay (fixed monthly versus pay-per-kWh), who bears generation risk (you versus the developer), and how the contract behaves over time. The choice depends on your demand profile, electricity price view, and operational preferences.

Headline answer

Solar lease (operating) gives fixed predictability — you pay the same monthly rent regardless of generation. PPA gives variability tied to actual production — you pay per kWh consumed. PPA shifts generation risk to the developer; lease keeps it with you. For sites with stable demand, both work; for sites with variable demand, PPA's pay-per-kWh structure aligns better.

Side-by-side

CriterionSolar lease (operating)Power Purchase Agreement (PPA)
Payment structureFixed monthly rent regardless of generationPer-kWh tariff on consumed solar
Generation riskLessee bears (lessor doesn't guarantee output)Developer bears (you only pay for what's generated)
Contract length5-8 years typical20-25 years typical
Balance sheet treatmentOff-balance-sheet (FRS 102 small-entity)Off-balance-sheet always
Ownership at endLessor; option to extend/acquireDeveloper; system can transfer at end of term
MaintenanceOften included in rentAlways included (developer responsibility)
Lifetime cost (£200k system)£40-70k more than capital purchase£400-700k more than capital purchase
Best forStable demand, 5-8yr contractual horizonVariable demand, 20+yr property tenure, zero capex priority

Which one for which situation

  1. How variable is your electricity demand year to year?

    Stable demand (manufacturing, continuous operations, 24/7 sites): lease is fine because you'll consume similar volumes each year. Variable demand (seasonal, holiday-affected, growth-trajectory uncertain): PPA aligns better because you only pay per kWh consumed.

  2. How long is your expected occupation of the building?

    Lease (5-8 years): manageable risk if you're uncertain about long-term occupation. PPA (20-25 years): much higher risk if your occupation horizon is uncertain. Match contract length to occupation certainty.

  3. Do you want operational simplicity or fixed-cost predictability?

    Operational simplicity (no metering complexity, no per-kWh accounting): lease — same payment every month, simple opex line. Fixed-cost predictability with consumption alignment: PPA — pay-per-kWh tied to actual consumption, lower bills in low-consumption months.

  4. Are you in a building that may be sublet or change tenants?

    Lease typically transfers more cleanly to new occupants because the obligation is "rent for asset access". PPAs are more complex on tenant changes because the offtake commitment needs to transfer or terminate. Multi-tenant or short-let buildings usually fit lease better than PPA.

Solar lease (operating) vs Power Purchase Agreement (PPA) FAQs

Is solar lease cheaper than PPA?
On most commercial sites, yes — solar lease typically costs £40-70k more than capital purchase over 25 years; PPA typically costs £400-700k more. The difference is in contract length and developer return. Lease is shorter (5-8 years) so the lessor margin compounds less. PPA is longer (20-25 years) so developer margin compounds materially.
Can I have a solar lease and a PPA on the same building?
Theoretically yes (e.g. lease the rooftop solar capacity, PPA the ground-mount adjacent). In practice unusual because installer/developer ecosystem is structured around one-or-the-other. Most projects pick one. Hybrid structures (lease for rooftop, PPA for adjacent solar farm) exist but require specialist developer engagement.
What happens at the end of the lease versus the end of the PPA?
Lease end: typically option to acquire system at fair market value, extend lease at reduced rate, or have lessor remove the system (rare). PPA end: typically system ownership transfers to building owner at no cost (or nominal value), or is removed if not commercially viable to maintain. Both structures need explicit end-of-term provisions in the contract.
Do solar leases and PPAs both qualify for SEG export tariffs?
For solar lease: lessee typically captures SEG export revenue (paying the lessor a fixed rent regardless of export). For PPA: developer typically captures SEG export revenue (factored into their return; offtaker only pays for self-consumed kWh). Confirm in the specific contract — both arrangements occur.
Which is more popular in the UK commercial market?
PPA dominates large-scale (£500k+) commercial solar projects because PPA developer ecosystem is larger and ticket sizes are higher. Solar lease dominates mid-market (£100k-£500k) where lessors compete on speed and structural flexibility. Capital purchase dominates the small-scale (<£100k) where capex is more easily absorbed.

Operating lease (full page)

Off-balance-sheet finance lease with fixed monthly rent. Mechanics, worked example.

PPA (full page)

Pay-per-kWh structure with developer ownership and operational responsibility.

Finance lease vs operating lease

The other lease comparison most often confused with this one.

Need this comparison run on your specific numbers?

We model both structures side-by-side using your postcode, half-hourly demand profile, accounting position, and balance sheet preferences. Five working days from enquiry to indicative comparison.

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