A solar array only makes power if the wiring behind it is right. Most of the calls we get in Frederick County aren’t about panels on the roof — they’re about the part underneath: the main panel that has to accept the backfeed, the AC disconnect Potomac Edison wants by the meter, and the conductors that carry the power down to your service. David Williams Electric is the licensed electrician (MD #11734) for that side of the job. We handle the grid-tie interconnection, the net-metering wiring, and the battery-ready inverter hookup so your system passes inspection the first time and your meter actually spins backward. Roofing and racking aren’t our trade; the electrical is, and after 30+ years wiring homes from Brunswick to New Market, we know exactly where these installs get hung up.
What an electrician actually does on a solar job
People assume solar is a roofing job. The roof part is real, but the system doesn’t turn on until the electrical is done — and that’s where permits get failed and projects stall. Our scope is the wiring, not the shingles: sizing and landing the conductors from the inverter, installing the exterior AC disconnect, and tying the solar into your main panel without overloading the busbar.
That last part trips up more Frederick County homes than anything else. The National Electrical Code limits how much backfeed a panel can take (the 120% rule), and a lot of houses here — especially older places in downtown Frederick and Brunswick — have a 100-amp or split-bus panel that can’t legally accept a 7 or 8 kW array without a fix. We’ll tell you up front whether your panel handles it, needs a line-side tap ahead of the main breaker, or needs a service upgrade to 200 amps before the solar company can finish. No surprises on inspection day.
Net metering and interconnection with Potomac Edison
Almost all of Frederick County is Potomac Edison territory, not Pepco or BGE — and that matters, because the utility you’re under decides the interconnection paperwork, the disconnect requirements, and how your net-metering credits get applied. A wiring layout that sailed through in Montgomery County under Pepco isn’t automatically what Potomac Edison signs off on here.
Maryland law lets residential solar net-meter, so the credits you bank in long July days carry against your winter bills. To earn them, the install has to pass Potomac Edison’s interconnection review and get a bidirectional meter swapped in. We wire the system to meet their disconnect and labeling requirements, coordinate the main-panel interconnection so it lines up with the Frederick County permit and inspection, and make sure the metering side is right so you’re not waiting weeks on a re-inspection to flip the system on.
Battery-ready inverters and main-panel work
More homeowners in Urbana, Lake Linganore, and Walkersville are asking us to wire their system battery-ready now, even if the battery comes later. That’s a smart call, but it changes the electrical plan — a hybrid inverter and a backed-up loads subpanel have to be designed in from the start, not bolted on after the fact. Retrofitting a battery onto a grid-tie-only install usually means redoing work you already paid for.
We’ll wire a hybrid or battery-ready inverter, set up a protected subpanel for the circuits you want running in an outage (well pump, fridge, a few lights), and make sure the main service can carry it. If your panel needs replacing or upgrading to make room, that’s electrical work we do every week — and you’ll get the price before we start, not after.
Working alongside your solar installer
You don’t have to have picked a solar company yet to call us. Some homeowners bring us in early to find out whether their panel and service can even handle the array they’re being quoted — a 20-minute look that’s saved people from a bad deal more than once. Others hire us to handle the electrical while a separate crew does the mounting and modules, which keeps the licensed work with a licensed electrician.
Either way you get the same thing: a straight answer on what your home needs, a written price up front, and a 100% satisfaction guarantee on the work. We serve Frederick, Urbana, Mount Airy, New Market, Middletown, Walkersville, Brunswick, and Myersville, and we’ve wired enough of these systems across the county to know what passes here.
Frequently Asked Questions
Does David Williams Electric install the solar panels themselves?
No — we handle the electrical side, not the roofing or racking. That means the main-panel interconnection, the AC disconnect, conductor runs, net-metering wiring, and battery-ready inverter hookup. Many Frederick County homeowners hire us for the electrical while a separate crew mounts the modules, which keeps the licensed wiring with a licensed electrician (MD #11734).
Will my electrical panel handle solar, or do I need an upgrade?
It depends on your panel. Code limits how much solar a panel can backfeed, and a lot of older homes in downtown Frederick and Brunswick have 100-amp or split-bus panels that can't take a typical array without a line-side tap or a service upgrade to 200 amps. Newer subdivisions in Urbana and New Market usually have the headroom. We'll check before any work starts and tell you exactly what's needed, with the price up front.
Who is my utility for net metering in Frederick County?
For almost all of Frederick County it's Potomac Edison, not Pepco or BGE. That's important because Potomac Edison sets the interconnection and disconnect requirements your install has to meet to get a bidirectional meter and start banking net-metering credits. We wire the system to their standards so it passes interconnection review the first time.
Can you wire my system to add a battery later?
Yes, and it's worth doing from the start. We install a hybrid or battery-ready inverter and a backed-up loads subpanel so adding a battery down the road doesn't mean redoing the wiring. Tell us which circuits you'd want running in an outage — well pump, refrigerator, a few lights — and we'll design the electrical around it.
Do you handle the Frederick County permit and inspection?
Yes. We pull the electrical permit, wire the interconnection to meet both the county inspector and Potomac Edison's requirements, and coordinate so the metering swap and final inspection line up. The goal is to pass the first time so your system isn't sitting dark waiting on a re-inspection.
Serving Frederick County
David Williams Electric provides solar installations throughout Frederick County, including Frederick, Urbana, Mount Airy, New Market, Middletown, Walkersville, Brunswick, Myersville. Explore all Frederick County electrical services or learn more about solar installations across Maryland. Call (410) 781-4357 for a free, up-front quote.
