Independent technical services

PV plant performance audit

A performance audit establishes how much energy a PV plant is losing and why. It compares actual output with expected output through the performance ratio, and locates faults with infrared thermography, I-V curves and on-site inspection. Carlos Jofré offers a remote diagnosis for CLP 490,000 and on-site audits from UF 45.

By Carlos Jofré · Updated October 10, 2026

Key points

Remote diagnosis from monitoring data: CLP 490,000 (up to 300 kWp).
On-site audit: from UF 45 to from UF 180, by plant size.
Report delivered 10 business days after the site visit.
Losses ranked by financial impact, with an action plan.

Who it is for

Companies whose self-consumption plant produces less than it used to, or never reached what was promised.
PMGD owners who want to check the work of their O&M contractor.
Buyers of operating plants (see also technical due diligence).
Plants coming out of warranty that need a baseline of their condition.

What it includes

Data analysis: monitoring and inverter data, ideally 12 months, and performance ratio calculation.
Visual and mechanical inspection of modules, mounting structure and cabling.
Infrared thermography of modules, junction boxes and switchboards.
I-V curves on a sample of strings.
Protection and earthing checks.
Loss report, ranked by financial impact, with an action plan.

Fees

Scope	Fee
Remote diagnosis from monitoring data, up to 300 kWp	CLP 490,000
On-site audit, up to 300 kWp	from UF 45
On-site audit, 300 kWp to 3 MW	from UF 90
On-site audit, PMGD of 3 to 9 MW	from UF 180

Fees are indicative. UF is Chile's inflation-indexed unit of account (ISO 4217: CLF). On-site work is included in the Santiago and Valparaíso regions; elsewhere, travel is charged at cost.

Process

Access to the monitoring portal and plant documentation.
Remote diagnosis from the data.
Site visit on a day with good irradiance.
Report and closing meeting.

Methods and standards

Performance ratio, as defined in IEC 61724-1: final yield divided by reference yield.
Outdoor infrared thermography, following IEC TS 62446-3.
I-V curve tracing, to measure the actual power of a string against its nameplate value.

As a Chilean reference, a Fraunhofer Chile study measured a weather-corrected performance ratio of about 75% in Santiago, with soiling reducing output by 0.13% to 0.56% per day between cleanings.

Independence policy

Carlos Jofré is the founder and CEO of SolarPro Chile, a solar installation and O&M company. For proposal reviews, audits, due diligence and expert reports he acts as an independent advisor: he discloses that relationship in writing, does not recommend SolarPro within the engagement and does not take engagements on projects or disputes involving SolarPro.

FAQ

Frequently asked questions

How often should a PV plant be audited?

Once a year as general practice, and whenever output drops without explanation, before a warranty expires, or before buying or selling the plant.

Does the plant have to be shut down?

Not for thermography, which is done with the plant generating under good irradiance. I-V curves require disconnecting each string for a few minutes.

Can the report support a warranty claim?

Yes. It documents faults with measurements and photographs, which is what manufacturers and installers ask for to process a claim.

Sources

Where the data comes from

IEC 61724-1:2021, Photovoltaic system performance – Part 1: Monitoring.
IEC TS 62446-3:2017, outdoor infrared thermography of PV modules and plants.
Urrejola et al., Effect of soiling and sunlight exposure on the performance ratio of photovoltaic technologies in Santiago, Chile, Energy Conversion and Management 114 (2016).
Service page in Spanish, with the price estimator.

Keep reading

Independent technical services