Solar Underperforming? Here's Who to Actually Call

You noticed your electricity bill is higher than expected. You open the monitoring app and the numbers look lower than last year. Something is off, but you don't know who's responsible — the installer who put up the panels, the inverter company, the panel manufacturer, or your utility. So you do nothing, because you don't know who to call.

This guide walks through exactly who to call, in what order, and what to say when you get them on the phone. It's a problem worth solving quickly: production guarantees have claim windows, and every month you wait may reduce your recovery rights.

What "Underperforming" Actually Means

Before you call anyone, it helps to understand which kind of underperformance you're dealing with. There are three distinct situations:

Shortfall against your production guarantee. Your contract promises a specific number of kWh per year (or per period). Your system is producing measurably less than that. This is the most financially significant situation and the one with the clearest remedies — your contract spells out what your installer owes you.

Underperformance against your installer's original estimate. Estimates and guarantees are different things. An estimate is a projection; a guarantee is a contractual promise. Many homeowners confuse these. Check your contract carefully. If you only have an estimate, not a guarantee, your legal position is weaker, though still potentially actionable under consumer protection law.

Normal panel degradation. Solar panels lose roughly 0.5% of their output per year — a rate documented extensively by NREL (National Renewable Energy Laboratory). After 10 years, your system should produce about 95% of what it did new. This is expected and usually not the installer's problem. Faster degradation — 1% or more per year — is a different matter and warrants investigation.

Understanding which situation you're in determines who you call first.

The Four Parties That Might Be Responsible

When something is wrong with solar production, four parties could be responsible. The symptoms point to different culprits:

In most real-world cases, the installer is the right first call — even if the root cause turns out to be a panel or inverter problem. Here's why.

Why Your Installer Is Usually the Right First Call

Your production guarantee is a contract between you and your installer. Not between you and Enphase. Not between you and the panel manufacturer. The installer signed that contract, and they're responsible for delivering on it — regardless of what equipment they chose to use.

Under most residential solar contracts, if an inverter or panel fails and reduces production below your guaranteed level, your installer is responsible for the production shortfall. The installer's claim against the equipment manufacturer is a separate dispute that's their problem to manage, not yours.

This matters practically: if you call the inverter company first and they say "contact your installer," you've lost time. If you call your installer first and they say "that's an inverter issue," you can correctly respond: "The production guarantee is between us. Please fix it."

The one exception is utility issues — if you suspect your net metering credits are wrong or your meter is misconfigured, call your utility directly. Your installer can't fix that.

What to Say on the First Call

Keep the first contact short and factual. Emotional language gives the installer room to reframe the conversation as a customer service issue rather than a contractual one.

A straightforward script:

"I'm measuring [X kWh] of annual production against a [Y kWh] production guarantee in my contract. That's a [Z%] shortfall. I'd like to formally open a production shortfall claim. Can you tell me your claim submission process and expected timeline?"

Three things to do before this call:

1. Pull your actual production data for the claim period from your monitoring app
2. Find your contract and locate the guarantee number and claim window
3. Send an email that mirrors the call — email creates a timestamped paper trail that phone calls don't

If Your Installer Points at the Equipment Vendor

This is the most common obstruction pattern. The installer tells you the shortfall is because of a failed Enphase microinverter, and suggests you contact Enphase. This deflection sounds reasonable — the equipment did fail — but it obscures the legal reality.

Your production guarantee is with your installer. A phrase that ends this deflection quickly:

"I understand the inverter may have contributed to the issue. The production guarantee in my contract is between me and [Installer Name], not between me and the equipment manufacturer. I'd like to discuss how you'll honor the guarantee, and separately, how you'll address the equipment under its warranty."

Keep the two threads distinct in writing. The production shortfall claim is against the installer. The equipment warranty claim may involve the manufacturer — but that's the installer's problem to manage, not a reason to delay your claim.

If the Installer Is Finger-Pointing with the Inverter Company

Some situations escalate to both parties pointing at each other simultaneously — the installer says the inverter is the problem, the inverter company says the system was installed incorrectly. This is covered in detail in our companion article When Your Installer and Inverter Vendor Blame Each Other.

The short answer: structured, time-stamped production data ends this dispute faster than any argument. When you can show 12 months of weather-adjusted production that's 18% below guarantee, neither party can credibly claim the problem doesn't exist — the debate shifts to who's responsible to fix it, which is a much more tractable question.

When Your Installer Is Out of Business

If your installer has gone bankrupt or simply shut down, the situation is more complicated. Production guarantee claims against a defunct installer are difficult to collect on directly. Your options shift to:

• The installer's surety bond (required in many states for licensed contractors)
• Your state contractor licensing board's recovery fund
• Equipment warranties with the panel and inverter manufacturers directly
• Your homeowner's insurance, depending on policy language

See our detailed guide: When Your Solar Installer Goes Bankrupt.

How OwlWatt Fits In (and What We Don't Do)

OwlWatt sits in one specific role: independent measurement. We pull your production data from your Enphase system, compare it to weather-adjusted baselines using NREL's PVWatts methodology, and calculate the gap between what your system produced and what your contract guarantees.

We produce a downloadable report with that measurement. You send it to your installer. We don't contact your installer. We don't represent you in the dispute. We don't take a cut of any settlement.

What the report does: it replaces the vague complaint ("I think my system is underperforming") with a structured, dated, methodology-documented claim that's much harder to dismiss. Installers who might argue with a verbal complaint have a harder time arguing with a PDF showing 14 months of weather-adjusted production data and an $847 calculated shortfall.

OwlWatt currently supports Enphase systems (Enphase Enlighten OAuth and IQ Gateway). SolarEdge support is on our roadmap — join the waitlist for SolarEdge release updates.