Skip to main content
DECARBR
Commercial solar PPA · capex · lease 50kW – 5MW
Rooftop · ground-mount · car port

Commercial solar that lands on the P&L — this financial year.

A typical 250kW rooftop pays back in 4–6 years on capex, or returns 25–35% off your unit rate from day one on a Power Purchase Agreement (PPA). We design, fund, and source MCS-certified EPCs for sites from a single warehouse to a multi-site portfolio.

Funded & insured by
NextEnergy Capital
Octopus Energy
A-rated UK insurers
Typical 250kW rooftop · light industrial
South-facing pitched roof, Midlands, 9am–5pm operations
£42k/yr
Combined bill saving + export income
Annual generation
237 MWh
Self-consumed (on-site)
~78%
Capex payback
~5.2 yrs
PPA discount vs grid
~32%
588
Panels (425W each)
52t
CO₂ saved/yr
30yr
Asset life
Modelled against your 12-month HH (half-hourly) consumption data.
Why commercial solar

Three reasons CFOs are signing this year, not next.

Full expensing on capex

100% first-year capital allowance on solar plant means a 25% effective discount for any limited company paying corporation tax.

PPA needs zero capex

A funder owns the system, you sign a 15–25 year discounted-rate offtake. Off-balance-sheet, OPEX-only, no capital approval.

Scope 2 reporting bite

SECR, CDP, and customer ESG asks now expect a credible decarb roadmap. On-site solar is the cheapest, fastest unit of progress.

Funding models

Three ways to put solar on the roof.

Most commercial sites end up choosing between capex (best lifetime return) and PPA (best cashflow). Operating lease is a niche middle ground.

OWN IT

Capex

You buy the system. Highest lifetime return, biggest cashflow hit upfront.

Upfront cost
£165k
Year 1 saving
£42k
Payback
~5.2 yrs
25-yr NPV
£780k
  • Full expensing — 25% tax saving
  • No third party on your roof
  • Direct claim on SEG export
NO CAPEX

PPA

A funder owns and operates. You buy the kWh you use at a fixed discount to the grid for 15–25 years.

Upfront cost
£0
PPA rate vs grid
–32%
Year 1 saving
£28k
Term
20 yrs
  • Off-balance-sheet — OPEX only
  • O&M and insurance bundled in
  • Buy-out option from year 7
MIDDLE GROUND

Operating lease

Tax-deductible monthly payments over 7–10 years, then you own the asset outright.

Upfront cost
£0
Monthly payment
£1,950
Net y1 cashflow
+£18k
Own asset from
Yr 8
  • Lower payment than capex finance
  • Off the corporation tax base
  • Final balloon optional
The kit · commercial spec

Built for 30 years on a working roof.

Commercial systems are a different category to residential — different mounting, different inverters, different monitoring. Same MCS standard, applied at scale.

Bifacial commercial panels

Trina or LONGi 540–580W bifacial modules — generate from rear-side reflected light too. 30-year linear performance warranty.

String or central inverter

SMA, Sungrow, or Huawei — sized for your roof's string layout. Hot-swappable, with built-in arc-fault detection.

Ballasted or membrane mounts

No roof penetrations on flat roofs. Pitched roofs use through-bolt or seam clamps appropriate to your roof spec.

Half-hourly monitoring

String-level visibility into 1-second resolution. Auto alerts on yield drop, MPPT failure, or string isolation.

Optional commercial battery

50–500kWh containerised LFP. Pays back on triad avoidance, peak shaving, or DSR (Dynamic Containment) revenue.

EV-charger ready

Spare DC-coupled capacity sized for 7–22kW workplace chargers — funded separately via OZEV WCS.

Live case study

A 320kW rooftop on a Midlands distribution centre.

Funded under a 20-year PPA. The site went from a £180k/yr electricity bill to £121k — and added a guaranteed-rate hedge against grid volatility for the next two decades.

PPA · 20yr 320kW Live since 2024 Logistics
Year 1 P&L impact Audited Apr '24 → Mar '25
Pre-solar grid spend
1.84 GWh @ avg 9.8p/kWh
£180,400
Self-consumed solar
Met 38% of total site demand
288 MWh
PPA cost (288 MWh)
Locked at 7.0p/kWh for 20 years
£20,160
Remaining grid spend
1.10 GWh @ avg 9.2p/kWh
£100,720
Net annual saving
Year 1 — before grid prices moved
£59,520
On-site economics

Self-consumption is where the money is.

A commercial system's payback is overwhelmingly driven by what you use on-site (priced at your grid rate) versus what you export (priced at SEG, ~5p). We size the system to maximise self-consumption against your actual load shape.

78%
Self-consumed
On-site usage during daylight
22%
Exported
SEG @ ~5p/kWh
14p
Effective unit rate
Avg saved by self-consumption
4.2 MWh/wk
Site daytime load
Modelled vs solar generation
Energy flow · live
SOLAR 12kW GRID 3kW BATT 8kWh SITE 14kW
How we deliver

From HH data to commissioning in 90–120 days.

Commercial solar takes longer than residential because of DNO approval and structural surveys — but every step is on a known critical path.

01
Wk 1

HH data + desktop yield

You share 12 months of HH consumption. We model yield, self-consumption, and PPA vs capex returns.

02
Wk 2–3

Site survey + structural

Roof load capacity, drainage, mounting choice. Drone scan if needed.

03
Wk 4–10

DNO + planning

G99 application for systems >50kW. Most planning is permitted development under Class J.

04
Wk 11–14

Install + commission

Most 250kW rooftops install in 6–10 working days. Commissioning + DNO approval to live within a fortnight.

Start with the data

Get a free desktop yield report.

Send us 12 months of half-hourly data and we'll model your roof, your load, and the financials for capex, lease, and PPA — side by side.

Modelled IRR & payback
For all three funding models — at your real load shape, not a generic profile.
PPA rates from 6 funders
We arrange the bid panel — funders compete on rate and term length.
Roof structural sign-off
Your install is conditional on a chartered surveyor's sign-off — never skipped.