Wind is financed against the yield a lender believes, not the one the bid assumed.
A wind project’s revenue is a weather forecast with a contract attached. The tariff is fixed and the machines are known; the uncertain line is how much the site will generate. So debt is sized on the conservative generation case, not the central one the tariff was bid on — and the lender set, the reserves and the failure modes below are all arrangements for living with that.
One dated rule sits on top of it, priced off a commissioning date rather than off the project: the interstate transmission charge waiver is now a staircase. It does not change the wind. It changes the model.
CRISIL Ratings on the ISTS waiver sunset, July 2025; SolarQuarter, 13 August 2025.
How the money is put together, and who puts it there
Tenor is read off the offtake, not off the machine: a 25-year central-agency power purchase agreement is what makes a long amortisation arguable at all. The lender list is long — public sector banks, IREDA, the infrastructure financiers, private banks, the development finance institutions — and it thins in three directions the list does not show. Many credit teams’ technical benches are staffed for solar, so a wind file is not refused but slow; merchant and open-access wind is underwritten as sponsor credit instead; and repowering sits between two products, because the existing offtake and the existing lease were both written for the old plant.
- Sizing case
- The conservative yield case, degraded again for availability, wake losses and electrical losses to the meter. The tariff was bid on a different one.
- Cover
- Tested on actual generation, which makes the covenant a weather test. Ask what a weak year does to it before signing, not during one.
- Sponsor support
- Released by performance tests the lender defines, not by the commissioning date. A different sentence, and worth reading slowly.
- Reserves
- Debt service, plus a major-maintenance reserve where the availability guarantee expires inside the tenor — usually missing from the sponsor’s model, never from the term sheet.
- IREDA
- Engages with a wind file on its own terms rather than as an unusual solar file. That difference is worth more than a margin.
- Development finance and climate funds
- Long timelines, and environmental and social requirements drafted as conditions precedent. Start them first or do not start them.
What kills wind deals
Almost none of these are technology failures. The machines work.
- A yield assessment the reviewer will not accept
- A mast that ran too briefly, sits too far from the site, or measured at the wrong height. The answer is not a refusal — it is a smaller loan, after the turbines are ordered.
- A tariff bid on the central case
- Auctions are won before financing closes. If the lender sizes on the conservative case, the gap becomes equity, at the worst point in the timeline to be looking for it.
- One parcel that does not close
- One owner who will not sell moves a machine, which moves the yield, which moves the debt — after the layout went in with the bid.
- Evacuation ready after the plant is
- A commissioned wind farm that cannot export earns nothing and still owes interest, and none of the clocks in the offtake documents stop while it waits.
- A commissioning date on the wrong side of a June
- Missing an ISTS step means a permanently higher cost of moving power, on a tariff bid against the previous number.
- Repowering treated as a new project
- The existing offtake was written for the old capacity and the lease for the old footprint, so the increment has nowhere to go. Solve the offtake for it first.
- Curtailment nobody modelled
- Grid-instructed backdown carries no compensation under many state offtake documents. Whether generation is deemed during curtailment is one clause, and it outweighs most of the ones that get negotiated.
Questions we answer in the first conversation
Worth settling while the layout and the bid are still changeable.
- What does the sizing case do to the equity requirement on this tariff?
- Which ISTS step does the commissioning date land on, and what does a quarter of slippage cost?
- Will a technical reviewer accept this yield assessment, and if not, what does the mast campaign need to look like?
- Where does sponsor support actually fall away?
- On a repowering: where does the incremental generation go?
Where we come in
While the yield assessment and the layout are still changeable, because both stop being changeable the moment a tariff is bid. We run the lender pack built on the conservative case rather than the promoter’s, the land and right-of-way position read the way a legal reviewer will read it, connectivity tracked as a dated item, and the file through appraisal, sanction and drawdown. If the tariff is already bid, the first thing we do is work out what the sizing case does to the equity requirement.
Send us the yield assessmentinfo@thebluridge.com