Solar Panel Electrical Connections: What Utah Homeowners Should Know
Rooftop solar is increasingly common across Utah, and most of the attention goes to the panels themselves. But the panels are only half the system. The part that determines whether solar is safe, code-compliant, and actually saves you money is the electrical connection — how the array ties into your home and the grid.
How solar connects to your home
A residential solar system has a few key electrical components:
- The array — the panels, which produce DC power.
- An inverter — converts that DC into the 240-volt AC power your home uses. Some systems use one central inverter; others use microinverters on each panel.
- A connection to your panel — where the solar power actually feeds your home's electrical system.
- Disconnects and labeling — so the system can be safely shut down, and so first responders know it's there.
The 120% rule
The most common electrical sticking point is how solar ties into your service panel. The code limits how much power can be back-fed into a panel based on the panel's rating — often summarized as the 120% rule. In plain terms, your existing panel and main breaker can only accept a solar backfeed up to a certain size.
If your panel is older, smaller, or already full, the installer may need to do a line-side connection ahead of the main breaker, or upgrade the panel. This is one reason two homes with the same number of panels can have very different installation costs — and why an experienced electrician should evaluate your panel before you sign anything.
Net metering and the meter
When your panels produce more than the house is using, the extra flows back to the grid. Utah utilities handle this through net-metering or export-credit programs, and the utility typically installs a meter that can measure power flowing both directions. Your solar installer coordinates this interconnection paperwork with the utility — but it's worth understanding that the credit you receive depends on your utility's current program, not just the size of your array.
Permits, inspection, and doing it right
Every residential solar install in Utah needs a permit and an electrical inspection, and the utility will not allow the system to turn on until it passes. Proper grounding, correctly sized conductors, code-compliant disconnects, and clear labeling all get checked. Cutting corners here doesn't just fail inspection — it creates a real fire and shock risk on your roof and in your panel.
Get an independent electrical opinion
Solar is a long-term investment, and the electrical foundation matters as much as the panels. Whiting Electric can evaluate your panel capacity, advise on whether an upgrade is needed, and handle the electrical work that ties a system safely into your Park City or Wasatch Front home — whether you're planning solar now or just want a straight answer before you commit.