Energy yield & assumptions review
Validation of energy-yield estimates and the assumptions behind the financial model.
Energy yield & assumptions review
We independently review energy-yield estimates and the assumptions feeding the financial model.
Losses, uncertainty and resource data are checked for reasonableness.
What this involves
For a renewable project the energy-yield estimate is the single number the entire financial model rests on, so it must be independently and critically reviewed. NEWATT examines the yield estimate and — just as importantly — the assumptions and data behind it.
We check the resource data and its long-term basis, the modelling methodology, the full loss chain and the uncertainty treatment that produces the P50 and P90 figures. Optimistic or unsupported assumptions are challenged, and we test how sensitive the yield is to the parameters that matter most to the lender.
The deliverable is an independent opinion on whether the yield is reasonable and bankable, a clear statement of where it is conservative or aggressive, and the adjustments we would recommend. This lets financiers rely on the P50/P90 numbers in the model with a documented, defensible basis behind them.
Scope in detail
Yield validation
We check the P50/P90 yield figures in the energy assessment for reasonableness against the resource data, loss assumptions and modelling methodology used to produce them, looking for figures that are optimistic relative to comparable projects in the same region and technology. Where a yield estimate looks aggressive, we trace it back to the specific assumption driving the gap rather than simply flagging the headline number as high.
Loss review
Loss assumptions — soiling, wake effect, availability, electrical losses, curtailment — are checked individually against industry-typical ranges and site-specific evidence, since an understated loss in any one category can materially inflate the modelled yield. We compare the loss breakdown against comparable projects we've reviewed or delivered, flagging any category that sits outside a defensible range without clear site-specific justification.
Uncertainty
We assess whether the uncertainty bands applied to the yield estimate genuinely reflect the quality of the underlying data — a short measurement campaign or a resource dataset far from site should carry wider uncertainty than the assessment may show. Uncertainty that's understated relative to the actual data quality is one of the more consequential gaps we look for, since it directly affects the P90 figure lenders rely on for financing.
Findings
Findings from the yield review are translated into a clear statement of impact — does the issue change the P50, the P90, or just the confidence around the existing figures — so the client understands the practical consequence, not just that an assumption was questioned. Where our review suggests a materially different yield figure, we show the recalculation so the client can see exactly how the revised number was reached.
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