Solar performance analysis: is your system doing what it was sold to do?

What solar performance analysis tells you

Solar performance analysis answers a simple question that most monitoring apps don’t: is this system producing what it should, given the weather it actually had? We build an expected-production baseline for each system and compare it with what the meter and inverter recorded. Then we put a dollar figure on the gap. If there’s a real problem, you get a short list of what a licensed technician should check. If there isn’t, you get to stop worrying.

Theo Okafor, our Performance Analytics Lead, runs this work.

The questions this discipline answers

• Is my system producing what it should, after accounting for this year’s weather?
• Did it ever produce what the proposal promised?
• Is a shortfall steady, seasonal or getting worse?
• What is the shortfall costing per year?
• Which of my sites needs attention first?
• Who should I call, and what exactly should I ask them to check?

Why it matters in Kentucky in 2026

Orphaned systems are common now. SunPower filed for Chapter 11 in August 2024, Sunnova followed in June 2025, and other installers and financiers have failed since. Their customers lost the people who used to answer the phone, and sometimes the monitoring login.

Lost production costs more than it used to. Most of the value of solar under Kentucky’s newer net metering terms comes from power you use on-site, which avoids the full retail energy charge. LG&E and KU rates rose in January 2026, so each self-consumed kilowatt-hour that goes missing now costs more.

The fleet is getting older. Systems installed during the last decade’s growth are aging, and a workmanship warranty is only as good as the installer behind it. Manufacturer equipment warranties are tied to the hardware, not the installer, but someone still has to notice the problem and assemble the evidence.

The quiet failure

The most expensive solar problems don’t look like problems. Take an illustrative system with two strings of panels feeding one inverter. If one string drops out, the system keeps producing, at roughly half its normal output on sunny days. The app still shows production every day. The owner blames a cloudy spring.

That’s why we never compare this June with last June. Weather moves production by more than many faults do. The right yardstick is what this June’s weather should have produced, and a weather-adjusted baseline separates a bad year from a broken system.

A second insight: some “underperforming” systems are working fine. It’s the original proposal that was optimistic. A technician can’t fix a sales estimate, so we compare the system with both physics and the proposal, and tell you which one is off.

Two services, two scales

	System Health Check	Portfolio Performance Reporting
Scope	One system, one time	Several systems, ongoing
Typical owner	Homeowner, small business, church	School district, franchisee, multi-building owner
Starting point	A suspicion, a bill, a closed installer	A stack of logins and no single view
Output	Report, baseline, technician list	Monthly or quarterly report, ranked alert list
Timeline	7 business days after data access is restored	Onboarding in 2–3 weeks

If your installer has closed, start with our checklist on what to do when your solar installer goes out of business. If you manage several buildings, our guide to five monitoring metrics that matter explains the measures we report.

Where the work stops

We read data. We don’t inspect, climb on, test or repair equipment, and we don’t do electrical work. When the data points to a physical problem, we tell you what a licensed technician should check and what a fair diagnostic visit should cover. Public and nonprofit owners can see how this fits their reporting needs on our nonprofits, schools and public bodies page.