For homes that already have solar

Is my solar system working?

Most owners never check. In five minutes, find out whether your panels are making what they should, and what to do if they aren't. You need two numbers: your system's size and what it made in the last year. We show you where to find both.

1. Where you live

State

2. Your system

System sizeOn your contract, permit or monitoring app.

Year it was turned onAn estimate is fine.

Don't know the size? Count the panels

Number of panels

Watts per panelOn the label on the back or side of a panel, or in your contract. Often 300 to 450.

Expected production, if you know itOptional, and better than our estimate: your contract or proposal usually lists it, or get it for your address from PVWatts.

kWh a year

Which way most panels face

Shade on the panels

3. What it made

Last 12 monthsOne monthLifetime total

Solar productionFrom your monitoring app. A full year evens out the seasons; a single month swings more with the weather.

kWh

Where to find it

Tesla app

Open the Tesla app, switch to your home (energy site) and tap Energy. Tap the Solar icon in the bar at the bottom, then switch the time view to Year (or Lifetime). The system size is usually under the site's settings or on your contract.

Tesla: energy data in the Tesla app

Enphase (Enlighten app)

Open the Enphase app and go to the Solar screen: it shows lifetime production, and you can run monthly reports from the menu. On the website (MyEnlighten), "Lifetime Values" is below the production graph. The Array view shows each panel, which helps spot one bad panel.

Enphase: how much energy is my system producing?

SolarEdge (mySolarEdge app)

Open the mySolarEdge app: the dashboard shows production for this month, this year and the system's lifetime. The layout view shows each panel's output.

Understanding the mySolarEdge app

Another app, or no app

Other inverter makers have their own apps (SMA Sunny Portal, Fronius Solar.web), and leasing companies like Sunrun have theirs. No app? Your contract or the installer can tell you the size, and the inverter itself often shows lifetime kWh on its screen. Your utility bill shows what you bought and sent back, not what the panels made, so it can't tell you production on its own.

Your answer appears here

Choose your state, then enter your system's size and what it made.

If it's making less than it should

Work through these in order. Most problems are found in the first three, and none of them need you on the roof.

Is the monitoring still connected? If the app shows nothing at all, the panels may be fine and only the monitoring is offline. A new Wi-Fi router or password is the usual cause. Reconnect the gateway or inverter to your Wi-Fi (the app or the installer can walk you through it).
Look for days with zero, or almost zero. Scroll through the daily view. A run of sunny days with nothing means the system was off: a tripped breaker, an inverter fault, or the utility switching it off. Production that stops abruptly in the middle of a sunny day can also be the system being curtailed (told to stop sending power to the grid).
Check the lights and the breaker. Look at the inverter, gateway or battery for warning lights or error codes, and check that the solar breaker in your electrical panel hasn't tripped. Don't open any equipment: take a photo of the lights or code for the installer.
Look panel by panel, if your app can. Enphase and SolarEdge apps show each panel. One panel far below the others usually means a failed microinverter or optimizer, which is often under warranty.
New shade or dirt. A tree that grew, a new building, or heavy dust, pollen or bird droppings can cut output. Rain cleans most panels; if they need washing, hire someone rather than climbing up.
Compare with the same month last year. A 5% to 10% difference from one year to the next is normal weather variation. A steady drop of 20% or more is worth a service call.

Who to call

You own it: start with your installer, under its workmanship warranty. For a failed inverter, microinverter or battery, the equipment maker's warranty usually applies, often through any qualified installer. If your installer has gone out of business, see what happens to warranties.
You lease it, or pay per kWh (a PPA): the company that owns the system is responsible for repairs. Many leases and PPAs include a production guarantee: if the system makes less than promised, they owe you a credit or a repair. Check your contract for it.
Not sure which you have? If you pay a monthly solar bill to a company, it's a lease, a PPA or a loan; the contract says which.

More for solar owners

Production guarantee checkLease or PPA: see whether the system fell short of the guarantee and what you're owed.
How to read a California true-up billThe once-a-year solar bill from PG&E, SCE or SDG&E, line by line.
Selling a house with solarOwned, financed or leased: UCC-1 filings, lease transfers and buyouts.
Replacing a roof with solar on itRemoving and reinstalling the panels: cost, who does it, and warranties.
When the installer has gone out of businessWhat still works, who you pay now, and who can fix it.
Lease and PPA terms by companyEscalators, transfers and buyouts at Sunrun, Tesla, SunStrong and others.
Solar company bankruptcy trackerWho services SunPower, Sunnova, PosiGen and other failed companies' contracts now.
When the leasing company won't answerHow to get a repair or a refund, step by step, in writing.
Reminders: a spring check and upcoming deadlinesAdd them to your calendar. Nothing is sent to us.

The box in the garage

With Tesla equipment, the label on each box says what it is. A Powerwall is a battery; a Backup Gateway switches your home to the battery in an outage and handles the monitoring; a Tesla Solar Inverter converts the panels' power for your home. A battery doesn't change how much your panels make, but it changes how much you send to the grid, so judge the panels by the Solar total, not by your bill.

How we estimate: your size × your state's typical yearly output per kW (NREL PVWatts), adjusted for the direction the panels face (east or west about 15% less than south, north about 30% less), for shade, and for aging of 0.5% a year. Shade varies a lot from roof to roof; these are rough allowances, not measurements. Monthly figures follow the usual seasonal pattern for your region (Climatebiz: solar panel energy production by state (Global Solar Atlas and NREL PVWatts)), so a single month is checked with a wider margin. For an exact figure for your address and roof, use NREL's free PVWatts calculator.

Sources: SolarReviews: best direction for solar panels; City Renewables: monitoring your solar system; Tesla: understanding your system production; Tesla: Powerwall system design.