Step 1: Sunlight hits your solar panels and creates electricity

Solar panels are built from photovoltaic (PV) cells — typically made from silicon. When sunlight strikes these cells, the energy dislodges electrons and generates a direct current (DC) electric charge. This process is called the photovoltaic effect, first documented in 1839 by Edmond Becquerel. There’s no fuel involved, no combustion, and no moving parts — just light converted directly into electricity.

A standard residential solar system in Pennsylvania has between 17 and 21 panels mounted on the roof, each capable of producing more than 400 watts under ideal conditions. The exact number of panels your home needs depends on your electricity usage, your roof’s orientation, and how much shading you have — use our solar panel calculator to estimate your system size.

Pennsylvania averages 4.0–4.9 peak sun hours per day depending on region, with southeast PA (PECO territory) receiving the most and northwest PA (Erie area) receiving the least. This variation directly affects how much electricity your system produces annually.

Step 2: The inverter converts DC electricity to usable AC power

The DC electricity your panels produce isn’t directly usable by your home — your appliances, lights, and outlets all run on alternating current (AC) at 120 or 240 volts. The inverter is the component that makes the conversion, and it’s arguably the most important piece of equipment in your system after the panels themselves.

Modern residential inverters are 97–99% efficient, meaning very little energy is lost in the conversion process. There are two main types used in Pennsylvania installations: string inverters (one central inverter for the whole system, lower cost) and microinverters (one small inverter per panel, better performance when shading is a factor). Both types include monitoring apps that let you track your system’s daily output in real time.

Microinverters have become the default choice for many PA installers because of the region’s variable weather and tree coverage — shading on one panel doesn’t reduce output from the rest of the array. Learn more about string vs. microinverter tradeoffs →

Step 3: Solar powers your home first — reducing your bill in real time

Once the inverter converts DC to AC, that electricity flows directly into your home’s electrical panel and powers whatever is currently running — your refrigerator, lights, HVAC system, EV charger, everything. Solar energy always gets used first, before your home draws anything from the utility grid.

Every kilowatt-hour your panels produce during the day is one you don’t have to purchase from your utility at current Pennsylvania rates (averaging $0.17–$0.21/kWh depending on your territory). A properly sized system for a typical PA home can offset $1,400–$2,400 per year in electricity costs through direct consumption alone.

Curious what your specific savings might look like? Our Pennsylvania solar guide includes a savings estimator broken down by PECO, PPL, Duquesne Light, and FirstEnergy territories.

Step 4: Surplus electricity flows to the grid and earns net metering credits

On a sunny afternoon, your panels often produce more electricity than your home is using at that moment. That surplus automatically flows back through your electric meter and into the utility grid. In Pennsylvania, your utility is required by law (PA PUC Title 52, Chapter 75) to track this export and credit your account at the full retail rate — this is called net metering.

Net metering credits roll over month to month. At the annual true-up date (May 31 for most PA utilities), any remaining credit balance is paid out at the lower “price-to-compare” rate. For most homeowners with a correctly sized system, net metering effectively brings the electric bill down to just the basic service charge for much of the year.

Important for PPL customers: PPL Electric has proposed replacing 1-to-1 net metering credits with lower wholesale rates, potentially effective July 2026. If you’re in PPL territory (Lehigh Valley, Harrisburg, Scranton areas), systems installed before the change may be grandfathered. See our PA net metering guide for full details →

Step 5: At night or on cloudy days, the grid (or a battery) covers your home

Solar panels don’t produce electricity after dark or during heavy cloud cover — that’s just physics. When the sun isn’t shining, your home automatically draws power from the utility grid, seamlessly and with no action required on your part. Your accumulated net metering credits offset the cost of this nighttime and cloudy-day grid usage.

For homeowners who want independence from the grid — or reliable backup power during Pennsylvania’s ice storms and nor’easters — a home battery (such as a Tesla Powerwall 3 or Enphase IQ Battery) stores surplus daytime solar energy so you can use it after sunset without touching the grid at all. A battery also keeps your home powered during outages, which a standard grid-tied solar system cannot do on its own.

With a correctly sized solar + battery system, many Pennsylvania homeowners achieve near-zero monthly electric bills year-round. Is a home battery worth adding to your system? →

Ready to go deeper? Here’s where to go next.

Now that you know how it works — find out what it would cost for your home.

Get a free, no-pressure solar consultation for your Pennsylvania home. We’ll assess your roof, run your actual utility numbers, and give you a straight answer on whether solar makes sense for your situation.