Data cleaning
Stuck or drifting sensors, missing periods, curtailment flags, and turbine event logs are reviewed, and every excluded period is documented.
Operational energy assessment
What your wind farm will produce, based on what it has produced.
An operational energy yield assessment uses the project's own SCADA or daily generation report (DGR) data to separate wind, availability, curtailment, and turbine performance, and to reset the P50 and P90 on evidence rather than pre-construction modelling.
SCADA or DGR10-minute or daily data
Operational P50 / P90long-term corrected
Loss bridgeexpected versus actual
What the assessment covers
Availability and curtailment
Turbine downtime, balance-of-plant outages, and grid backdown are separated, so each loss is assigned to the right cause and the right party.
Power curve performance
Each turbine's measured power curve is compared with the warranted curve after air-density correction, to find turbines that are underperforming and by how much.
Long-term correction
A few operating years may have been windier or calmer than normal. Production is corrected to the long-term wind climate using reanalysis or met mast references.
Loss bridge
The original EYA is reconciled with actual production, step by step: wind resource, availability, grid, wake, and turbine performance.
Operational P50 / P75 / P90
An updated energy estimate based on measured production, usually with a narrower uncertainty than the pre-construction assessment.
Data we work with
- 10-minute SCADA: wind speed, power, status codes, and nacelle direction for each turbine.
- Daily generation reports (DGR) and monthly joint meter readings, common for Indian assets.
- Turbine alarm and event logs, and availability reports from the O&M contractor.
- Grid backdown and curtailment records.
- Met mast or LiDAR data on or near the site, where available.
- The original pre-construction EYA and the turbine supply and service agreements.
Why operational data changes the P90
A pre-construction EYA estimates production from a short measurement campaign and a flow model. Once a wind farm has operated for a few years, its own production record replaces many of those modelled assumptions. Flow modelling, wake, and turbine performance uncertainty are largely replaced by measured results, so the gap between P50 and P90 usually narrows.
That only holds if the operating data is cleaned properly. Periods of curtailment, downtime, or faulty sensors that stay in the record distort the long-term estimate and can move the P50 in either direction. The value of an operational assessment lies mostly in that filtering and in documenting it so a lender can follow it.
Frequently asked questions
How much operating data is needed?
One full year is the practical minimum. Two to three years gives a much more reliable result, because it shows how the asset performs across different wind years and seasons.
Can you work with DGR data only, without SCADA?
Yes. Daily generation reports support a long-term corrected production estimate, availability analysis, and a loss bridge. Identifying individual underperforming turbines needs 10-minute SCADA.
Can you find turbines that are underperforming?
Yes, with 10-minute SCADA. Each turbine's power curve is compared with the warranted curve and with its neighbours, and the energy lost is quantified to support a warranty or O&M discussion.
Are nacelle anemometers reliable enough?
Not on their own for absolute wind speed, because the rotor disturbs the flow. They are used with a transfer function, compared between turbines, or checked against a met mast or reanalysis reference.
Is the result suitable for refinancing?
Yes. The operational P50 and P90 are reported with the uncertainty budget and data filtering documented, so a lender's technical advisor can review them.
Is your wind farm producing what it should?
Share a summary of the SCADA or DGR data you have, and a scoping call will set out what the assessment can show and a fixed fee.