- Year-1 net cash
- Both positive
- 25-year NPV
- In-house 2-4x stronger
- Asset control
- In-house = corp owns
- Default route
- In-house Salix-funded
Side-by-side comparison
| Dimension | In-house Salix-funded | PPA | Operating Lease |
|---|---|---|---|
| Asset ownership | Corporation | Third party | Lessor |
| Capital outlay (corp) | £0 (loan-funded) | £0 | £0 |
| Operating cost | Salix repayment | Per-kWh purchase | Annual lease |
| Year-25 outcome | Corp owns asset; 100% to bottom line | PPA contract ends; buy-out option | Lease ends; buy-out or renew |
| Year-1 net position | Cash-flow positive £15-50k | Cash-flow positive £3-10k | Cash-flow positive £2-8k |
| 25-year NPV (typical 200kW) | £1.1-1.6m | £300-600k | £200-400k |
| Capital risk to corp | Low (Salix from savings) | None | None |
| Operational complexity | Low (asset under corp control) | Moderate (PPA provider on site) | Moderate |
| Climate Action Plan reporting | Strong (owned asset, owned tCO2e) | Moderate (purchased renewable) | Moderate |
| Corp board governance | High preference | Medium | Medium-low |
| Eligible since Nov 2022 | Yes (Salix unlocked) | Always (commercial market) | Always |
The default recommendation: in-house Salix-funded
For virtually every UK FE corporation in 2026, in-house Salix-funded ownership wins. The pre-November-2022 calculus has changed:
- Salix is now open to every FE corp. The historical reason for PPA — avoiding capital cost when grant/loan finance wasn't available — has gone.
- Capital risk is genuinely low. Salix energy savings calculation is conservatively modelled; repayment is from realised savings.
- 25-year NPV is 2-4x stronger than PPA. The corporation captures full upside.
- Asset is under corporation control. Maintenance, upgrade, expansion decisions are made by the corporation.
- Climate Action Plan reporting is cleaner. Owned asset, owned tCO2e reduction, owned data.
When PPA might still win
Three narrow scenarios where PPA remains the right choice:
1. Corporation board explicitly refuses any borrowing
Some boards (typically smaller corporations with debt-averse trustees, or those recovering from financial distress) refuse Salix borrowing even though it's interest-free. In that case PPA delivers solar with literally zero balance sheet impact.
2. Complex multi-tenant or shared-estate
Where the campus is shared with another organisation (local authority, NHS, university partner), PPA can simplify the legal structure. The PPA provider sells output to whichever entity has the energy account.
3. Very short remaining lease horizon
If the corporation leases the building with less than 10 years remaining, Salix may not be viable (can't commit to 8-year asset operation on a 6-year lease). PPA can work with shorter-term contract structures.