P50 / P90 estimates
Probability-of-exceedance yields for financing and investment decisions.
P50 / P90 estimates
We derive P50, P75 and P90 yields for the financial model.
Exceedance probabilities are clearly stated.
Scope in detail
P50
The P50 figure represents the central, most-likely estimate of annual energy yield, derived from the full resource and loss analysis rather than a simplified rule-of-thumb calculation. We present the P50 alongside the specific assumptions driving it, so it functions as a genuine best estimate rather than a marketing number optimised to look favourable.
P90
The P90 figure — the yield level expected to be exceeded 90% of the time — is calculated from the combined uncertainty distribution around the P50 estimate, and is typically the figure lenders size debt against, so getting the uncertainty analysis right matters more here than almost anywhere else in the assessment. We're deliberately conservative where data quality doesn't support a tighter distribution.
Exceedance
Full exceedance probability curves — P50 through P99 and beyond — are provided rather than just the headline P50/P90 figures, since different stakeholders in the financing structure often need different confidence levels for their own risk assessment. Curves are generated directly from the underlying uncertainty distribution, not interpolated from a handful of points.
Bankable output
Yield figures are delivered in the format and with the supporting documentation a project finance lender's technical advisor expects — methodology, data sources, assumptions and uncertainty analysis — so the numbers can be relied upon in a financing process rather than requiring rework by the lender's own advisor. This is the output stage where rigour in every earlier step actually pays off.
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