One operating site, a defined method and a fixed fee: performance reconciled against a rebuilt expectation, faults located to string and inverter level, O&M and warranty position tested, and every finding priced in yield and in money.
- Measured output against a rebuilt expectation from real weather data
- String and inverter-level analysis to locate where the yield is going
- Degradation against warranty, and inverter fleet position
- O&M contract performance against the SLA
- A ranked remediation list with costs and paybacks
Underperformance is rarely dramatic. It is two per cent here and one and a half per cent there, for years, and it survives because the monitoring platform reports availability rather than yield and nobody is reading it critically.
The Asset Health Check is the engagement we are most often instructed on: one operating site, a defined method, a fixed fee, and a report that puts a number on every finding. It is also the first step of a Portfolio Review and a common precursor to a refinancing or a sale.
What is examined
Performance reconciliation. Measured output against a rebuilt expectation, using performance ratio analysis on the principles of IEC 61724. Not the installer’s original yield model but a fresh one, because the original is usually optimistic and always out of date.
String and inverter-level analysis. Where the monitoring granularity allows it, this is where faults hide. A handful of underperforming strings is invisible in the headline number and material in the annual total.
Degradation against warranty. Whether observed decline is normal ageing, a warranty claim the owner is entitled to make, or something else entirely.
Inverter fleet position. Age against design life, spares availability, obsolescence exposure, and what replacement would cost and yield if brought forward. For assets built in the ROC and Feed-in Tariff era this is now the dominant question.
Thermography and condition. Review of existing imagery where it exists, or a specification for getting it done properly if it does not.
O&M contract performance. What the provider committed to, what they have actually delivered, response times against the SLA, and whether the scope quietly excludes the things that have gone wrong.
Safety and compliance. DC isolation, labelling, fire and structural considerations, and the evidence position if an insurer or a buyer asks.
What the client receives
A findings report with each issue quantified in annual yield and in money at a stated price assumption, ranked by the value of remediation against its cost. The output is a decision list, not an observation list. A call to go through it with the owner, the asset manager or the investment team is included.
When it is bought
- Before a refinancing, sale or fund-level valuation, to know what a buyer’s adviser will find first
- When the numbers have drifted and the O&M provider’s explanation has stopped being convincing
- When an inverter fleet is approaching end of life and the replace-or-repower question needs an answer
- As the first step in a portfolio review, on the asset that worries the owner most
Why a fixed fee
The value of the work is the yield it finds, not the days it takes. A 15 MW site losing three per cent is losing tens of thousands of pounds a year at merchant prices. Pricing that by the day would be a negotiation about days; pricing it by the site is a decision about whether the owner wants to know.
Fees are quoted by installed capacity band and confirmed in writing before any work starts. Site visits, where the question needs one, are scoped separately.
Other services
Tell us what you are trying to decide
Most engagements start with a short call about the asset, the transaction or the dispute, and the timetable. We will tell you what we would do, what it would cost, and whether you need us at all.