How to Read a Solar Monitoring App

The maintenance page tells you to open the app once a week. This page is what you are looking at. Washing, pollen, and lovebugs stay on the maintenance page. A dark afternoon that is only a thunderstorm stays on the clouds page.

Three numbers, and only one of them is the bill

A kilowatt (kW) is power right now, like the speedometer. A kilowatt-hour (kWh) is energy over time, like the odometer. The app uses both. The bill mostly uses kilowatt-hours.

Production is what the panels made. Consumption is what the house used. Export is the leftover that went out to the utility. Import is what you bought from the utility when the panels were not covering the load. Production is not export. A house that runs the air conditioner at noon can make 40 kilowatt-hours and send back 10. The other 30 never left the building.

The utility meter is only on the wire between you and the grid. Florida Power & Light (FPL) says this in its own net-metering notes: the meter does not see the kilowatt-hours your home used as they were made. FPL labels the two directions on a bidirectional meter. “DEL,” or a plus sign, is energy delivered from FPL to you. “REC,” or a minus sign, is excess you sent them. “NET” on a smart meter is the difference. Your bill does not contain a line for total solar production. The inverter, or the app talking to it, is the place that number lives.

Orlando Utilities Commission (OUC) uses different words for the same split. Customer-Supplied kilowatt-hours are the excess you sent them, not the total the array made. OUC’s own example: if the panels made 1,000 kilowatt-hours and Customer-Supplied is 400, the house used 600. On OUC’s usage dashboard, kilowatt-hours Delivered are what OUC sent you, and kilowatt-hours Received are what you sent back. You earn a bill credit only when what you sent exceeds what you took. You still pay the customer charge. The app’s calendar month and OUC’s billing cycle often do not match, so do not expect the two totals to agree on the first try.

Duke Energy Florida is the same kind of grid meter. The bill can show what you took and what you sent. It is not a copy of the app. Year-end leftovers on Duke and FPL are paid at a cheap rate. That part is the utility page. The monitoring point is simpler. If someone adds the app’s production to the bill’s export, they counted the noon air conditioning twice.

What the app can see, and what was never installed

Most systems report production if the installer connected the gateway to the internet. A gateway is the small box, or the radio inside the inverter, that sends the numbers to a website. Enphase calls recent ones an IQ Gateway. Older ones were an Envoy. SolarEdge usually reports from the inverter itself. Tesla, and a few others, use their own app. The brand does not matter. The question is whether anyone finished the setup, and whether the password still works.

House consumption is optional hardware. Enphase’s consumption monitoring needs extra sensors called current transformers, clamps that sit around the wires in the main panel, and it needs the gateway configured to believe them. Plenty of Florida installs never got those clamps. The app then shows a pretty production curve and a blank, or a guessed, consumption number. If consumption is a perfect mirror of production all day, Enphase’s own note says the usual cause is a setting turned on without the clamps installed. That graph is not your house. Ask the installer to turn the fake consumption view off, or to install the clamps. Do not remodel your habits around a mirror.

Panel-level detail depends on the equipment. Microinverters and optimizers can show one rectangle per panel. A plain string inverter often shows one number for a whole group. A single shaded or dead panel is obvious on the first kind and invisible on the second, until that group drops. The inverter page is why that difference was a purchase decision. After the fact, it is why “the app looks fine” can still hide one bad panel on a string system.

A normal Central Florida day

On a clear day the curve rises after sunrise, peaks around solar noon, and falls toward evening. Solar noon here is not 12:00 on the kitchen clock. It is a bit after, and daylight saving time moves the clock without moving the sun. A curve shifted an hour after a time change is not a failed array.

Spring is often the best season. Summer weekdays have a strong morning and, many afternoons, a cliff when the storm builds. Winter days are shorter, so the total is lower even when the sky is blue. A clear October day will not match a clear April day. Compare like with like.

A flat top on an otherwise smooth curve, on a cool bright day, is often clipping. The panels could make more than the inverter is allowed to turn into house power, so the app draws a plateau. That is a design limit, not dirt. It is also not free energy you can recover by washing. The inverter page explains it.

A useful check, already on the maintenance page: if a clear, unshaded day is down more than about 10 percent from a similar clear day and nothing in the house changed, look for a film on the glass, a tripped breaker, a new tree shadow, or a fault. Do not climb the roof to find out. Binoculars from the ground, then a licensed person if something looks lifted or cracked.

Which zero is a real zero

• Night, or a gateway that says the last report was at sundown. That is a working system with the sun down.
• “Gateway offline,” “envoy not reporting,” or a Wi-Fi error, while the house is bright and the utility meter is still moving backward at noon. The array may be fine. The internet path died. A new router, a changed Wi-Fi password, or a storm that knocked out the modem does this constantly. The solar breaker and the gateway are sometimes different breakers. Look at the inverter’s own lights before you assume the panels quit. Production during the outage may show up later, or it may leave a gap in the graph. The gap is missing data, not always missing electricity.
• The app is online, it is noon, the sky is clear, and production is zero or every panel is red. That is a stopped system. Check the solar breaker in the main panel. Check for a grid-outage or anti-islanding message, which means the inverter turned off because the utility is down or the voltage is outside its window. If the breaker is on and the grid is up, stop flipping things and call a licensed electrician or the company that still honors the workmanship warranty.
• One panel, or one string, at zero while the neighbors are producing. That is a bad unit, a connector, or a hard shadow, not a reason to wash the whole roof. Screenshot the layout before the color changes back.
• The app shows production and the bill did not shrink. First check the dates. Then check whether you used the power in the house. Then check which utility wrote the bill. A healthy array can still leave you owing OUC if you imported more than you exported, plus the customer charge.

A hurricane outage belongs in the first real-zero list only while the grid is down. Grid-tied inverters are required to turn off so they do not energize a dead line. The app showing zero that afternoon is the inverter obeying. The hurricane page is what comes back on when the utility does, and what a battery changes.

The login is part of the system

The company that commissioned the array is often the one holding the administrator seat. You may have a view-only link, or a login they created and never gave you the password to. Get owner access in your name and your email before you need it. If the company closes, the manufacturer is the party that can move the site. They will ask for proof you own the equipment: a contract, a permit, or a closing paper. The installer-gone page is that phone call. Do not wait until the app has already locked you out.

If you buy a house with panels, the transfer is a closing item, same as the garage-door remote. The closing checklist already asks for it. An app that still says the seller’s email is a system you cannot see, and a warranty you may not be able to file.

Alerts deserve the same ownership. Turn them on to your phone, not only to the installer. A ground-fault or arc-fault message is a call. A one-hour communication blip during a thunderstorm is usually not. “Production below estimate” on a stormy week is the weather. The same alert on a week of blue skies is the 10 percent check.

What to save before you call

A technician can do very little with “it seems low.” They can do a lot with five pictures.

• The energy graph for a clear day this month, and a clear day from a similar month if you have it.
• The panel map, if the app has one, with any red or gray modules visible.
• The exact alert text, not a paraphrase.
• Whether the gateway says online, and the time of the last report.
• The solar breaker’s position, on or off, and whether the rest of the house has utility power.

Then look at the bill only for the matching idea: delivered and received, or OUC-supplied and customer-supplied. Do not send the app total and call it the credit. Once a year, put the app’s annual production next to the proposal’s estimate. A typical year already includes clouds. A year that is far below that estimate, on a roof that did not grow a new oak, is when you stop refreshing the app and start the warranty. The proposal number is the worth-it page. The app is how you find out the roof is not living up to it.

This page is general information, not a diagnosis of your system. Breakers, wiring, and the roof are work for a licensed person. The app is how you decide whether to call one.