When I got my Span smart panel installed alongside my Tesla Solar system, I had a very specific vision in mind. I wanted to open the Span app on a Tuesday afternoon and watch in real time as my solar panels shaved the load off each circuit in my house — see my kitchen dropping from grid power to solar-covered, watch my HVAC get partially offset during peak sun hours. That granular, circuit-level solar picture is a big part of what Span promises.
That vision never materialized. And after a lot of head-scratching and a call with Span’s support team, I finally understood why: my installer had wired my Tesla inverter output to the service entrance — the point where utility power comes into my house — rather than to a breaker inside the panel itself. As a result, Span never sees the solar electricity at all. It monitors circuits inside the panel. The solar power bypasses the panel entirely and goes straight to the meter.
This is more common than you’d think, and if you’re in the same situation, it’s worth understanding exactly what happened and what your options are.
Two Ways Installers Can Wire a Solar Inverter
There are two valid places a solar installer can connect a grid-tied inverter’s output in a residential system.
The first is inside the breaker panel, via a dedicated solar breaker. Your main panel has a row of breakers — water heater, dryer, kitchen circuits, and so on. With this method, the installer adds a breaker specifically for the solar input, usually at the bottom of the panel (NEC code requires it to be within a certain distance of the main breaker, depending on your panel’s busbar rating). Power flows from the inverter, through that breaker, onto the panel’s busbar, and from there to your circuits. When the sun is out and your panels are producing 4 kW, that 4 kW enters the bus and gets consumed by whatever is running in the house before the rest gets pushed back to the meter.
This is the configuration Span expects. When solar comes in through that breaker, Span can see it as a source, subtract it from your consumption circuits, and give you accurate solar offset data per circuit.
The second method is the service entrance connection, also called a line-side tap or supply-side connection. Instead of going into the breaker panel, the inverter output connects to the wires between your utility meter and the main breaker. Electrically, it achieves the same result — solar goes into your home’s wiring and either gets used locally or pushed back to the grid. From the utility’s perspective, both methods work the same way. From Span’s perspective, the second method makes solar completely invisible. Span monitors what happens after the main breaker. Anything upstream of it — including line-side solar — is outside Span’s view.
My system uses the second method. My inverter output is tapped into the service entrance. The Span panel has no idea solar exists.
Why Installers Choose the Service Entrance Method
I asked my installer about this after the fact. His explanation was straightforward: the service entrance connection is simpler and often cheaper. Running conduit and wiring to a breaker slot inside the panel means working inside the energized panel, coordinating the location of the solar breaker relative to the main (there are code constraints around “backfed breakers”), and ensuring the panel’s busbar can handle the additional capacity. With a line-side tap, the installer works upstream of all that complexity. The utility usually requires a simple notification or permit — same as the load-side method — and the electrical code allows it under NEC 705.12(A).
There’s also a practical reason that comes up with older or smaller panels: if your main panel doesn’t have room for a solar breaker, or if the busbar amperage rating would be exceeded by adding solar (the “120% rule”), a service entrance connection sidesteps those constraints entirely. It’s not a shortcut in a negligent sense — it’s a legitimate installation method that meets code. It’s just one that wasn’t designed with smart panel monitoring in mind.
The problem is that smart panels like Span weren’t common when most residential solar wiring practices were codified. The assumption was that circuit-level monitoring wasn’t something homeowners cared about at this granularity. Now that Span has changed that expectation, the wiring choice that used to be a pure convenience decision now has monitoring implications that nobody was thinking about during install.
What You Lose With a Service Entrance Connection
If your inverter is wired before the panel, here’s what you actually lose in Span:
No solar production visibility in Span. The Span app won’t show you a solar production number at all — or if it does attempt an estimate, it’s doing so by inference, not by actually measuring your inverter output. In my case, the app just shows consumption per circuit with no solar data.
No circuit-level solar offset. This is the one that stings. Span can tell you your refrigerator is drawing 1.2 kWh per day and your EV charger pulled 18 kWh last night. What it cannot tell you is how much of that came from solar versus the grid, because it doesn’t know solar production happened.
No time-of-use solar optimization data. Span has a feature for managing circuits around time-of-use rates — shedding loads during peak pricing windows, for example. Without knowing how much solar is available at any moment, that optimization is working with one hand behind its back.
Span’s home energy dashboard is incomplete. That satisfying flow diagram showing solar → home → grid → battery? It won’t show your solar input if Span can’t see it. You’ll have a consumption-only view.
What you don’t lose: all of Span’s consumption monitoring still works perfectly. Every circuit, every breaker, real-time wattage, historical trends, remote breaker control — all of that functions normally. Span is still a genuinely useful device, just not for the solar production picture I wanted.
Where to Actually Get Your Solar Production Data
The saving grace in my situation is the Tesla app. Because I have a Tesla Solar inverter, the Tesla app has full production data — how many kWh were generated today, peak production, historical production by day/week/month. It pulls this directly from the inverter, independently of the Span panel, so the wiring arrangement doesn’t affect it.
If you have a SolarEdge inverter, the SolarEdge monitoring portal gives you the same thing. Enphase systems report through the Enlighten app. Whatever brand your inverter is, it almost certainly has its own monitoring platform that doesn’t care where the output was wired.
The manual math workaround: the Tesla app gives me production, the Span app gives me total consumption. If production minus consumption is positive, I’m exporting to the grid. If it’s negative, I’m drawing from the grid. It’s not the seamless, circuit-level picture I wanted, but it’s the data I need to understand my energy situation.
Can You Fix It After Installation?
Yes, but it costs money. What you’re asking for is a rewire: the electrician disconnects the inverter output from the service entrance and reconnects it to a breaker inside the panel. Depending on your panel layout, available breaker slots, and conduit routing, this is typically a few hours of work for a licensed electrician. The quotes I’ve gotten ranged from $500 to $1,500 depending on complexity.
Before pursuing this, verify that your main panel can support a load-side solar connection. The NEC 120% rule says the solar breaker amperage plus the main breaker amperage can’t exceed 120% of the busbar’s rating. If your panel is already at or near that limit, you may need a panel upgrade before a load-side connection is possible — at which point the cost calculus changes significantly.
It’s worth calling your solar installer first. Some installers will do this rewire as a warranty repair if they can be convinced the original wiring choice didn’t meet your expectations. That’s a conversation worth having before you hire an independent electrician.
If you’re still pre-installation and reading this as research: ask your installer explicitly how they plan to connect the inverter output, and specify that you want a load-side connection (i.e., via a breaker inside the panel) if you want Span to have solar visibility. Get it in writing.
The Bottom Line
The Span panel is a capable device, and I don’t regret having it. But the solar monitoring blind spot is real, and it’s caused by an installer wiring decision that doesn’t get discussed enough when people are considering both Span and solar together. If your inverter feeds into the service entrance rather than a panel breaker, Span will never see your solar production — by design, not by defect.
For production data, use your inverter’s native app. For consumption data and circuit-level control, Span does that well. The two together give you most of the picture, just not through a single app the way I’d hoped.
If monitoring solar through Span is important to you, confirm the wiring method before installation. That conversation is a lot cheaper than fixing it afterward.