Solar bankability: what a lender checks before financing a rooftop or ground system
A solar system is bankable when its cash flow survives a bad year. The lender sizes the debt on a conservative yield, checks who stands behind the equipment, and waits for the connection approval before releasing money.
Take the project bankability test
The five checks
- Yield: an independent simulation with a P50 (expected) and a P90 (conservative) case. Debt is sized on P90
- Equipment: panels and inverters from makers with a track record, with product and performance warranties on paper
- Connection: the grid connection or net metering approval, usually a condition before disbursement
- Cash flow: capex, annual saving or revenue, payback and debt service cover
- Owner's contribution: the share of cost the owner funds, often 20 to 30 per cent
Why the installer's number is not enough
An installer's yield estimate is a sales figure. A lender needs a simulation it can test: site data, losses, degradation and the P90 case. The gap between P50 and P90 is the margin of safety the loan is built on.
Before you sign the installation contract
Check the equipment against the credit line's eligible list, get the warranties in writing, and confirm the connection route. Fixing these after signing costs time and sometimes the green pricing.
Solar bankability check
Vendor, yield and green-loan eligibility reviewed the way a lender reads them, before you sign the installation contract.
From EGP 15,000. How engagements run
Questions
What is P90 in solar finance?
The annual energy output the system is expected to exceed in 90 per cent of years. Lenders size debt on it because it protects repayment in poor years.
Do green credit lines finance rooftop solar?
Many do, when the equipment meets the line's eligibility criteria and the saving is documented.
What payback does a lender want?
There is no single number. A shorter payback eases approval; a longer one needs a stronger cash flow case and often a larger owner's contribution.
Cite this guide
Hamdy, O. (2026) "Solar bankability: what a lender checks before financing a rooftop or ground system". omarhamdy.com. https://omarhamdy.com/guides/solar-bankability/