Solar panels in Alpharetta, GA

Roofs in Alpharetta get about 1,538 hours of usable sunlight a year — more than 56% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.

Check your specific roof in Alpharetta → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.

What a typical Alpharetta solar system costs

A 21-panel system (8.4 kW) is about right for an average Alpharetta home using 10,800 kWh a year. It would produce roughly 10,981 kWh annually and offset 100% of that usage.

How we worked this out for Alpharetta

Every number on this page comes from these seven steps. Nothing is a national average — the sunlight figure is measured from Alpharetta rooftops.

Step 6 matters more than it looks. Only 34% of what a system this size produces in Alpharetta is used the moment it is generated; the other 7,201 kWh is exported and credited one-for-one under net metering. Because exports here are credited at or near retail, that split changes the payback very little — 10.8 years against the 11 we show. In places where exports pay a fraction of retail the same split moves payback by years, which is why we model it explicitly rather than assuming.

Assumptions: 400W panels, 15% system losses (inverter, wiring, heat, soiling), $2.85/W installed, 10,800 kWh typical annual household use, 14.1¢/kWh electricity. Change any of those and every figure above moves — which is exactly why a single national "solar costs X" number is misleading.

Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.

Why Alpharetta gets 1,538 sun hours

That figure comes from Google's analysis of real rooftops across Alpharetta — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in Alpharetta reaches about 1,717 hours, roughly 12% better than typical.

The numbers behind this page

When Alpharetta actually produces

Annual totals hide the thing that catches people out: 34% of Alpharetta's yearly sunlight arrives in May–July, and just 15% across November–January.

Output is unusually steady — only about 2.4× between Jun and Dec. Alpharetta is close enough to the equator that seasonal variation is mild, which makes sizing a system considerably more predictable.

The annual total is measured from Google's rooftop imagery. Its split across months is calculated from solar geometry at Alpharetta's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.

How Alpharetta compares to the other 788 cities

What actually stands out about Alpharetta:

• Shading is a real problem here. Alpharetta loses 10% of its potential sunlight to trees, chimneys and neighbouring buildings — the 60th-worst of the 788 cities measured. Panel placement matters more here than in most places, and a roof survey is worth more than a phone quote.
• Plenty of roof to work with. Typical roofs here fit around 91 panels — roughly 4× what an average home needs. Roof size will not be what limits your system in Alpharetta.
• Large roofs. At a median of 376 m², Alpharetta has the 38th-largest typical roof footprint we've measured.

Cities with almost the same sunlight

These are the closest matches to Alpharetta's 1,538 usable sun hours from other states and provinces. Same sunlight, different electricity prices — which is usually what decides whether solar is worth it.

Nearby cities

See all of Georgia → statewide sunlight, rates, incentives and every city we've measured.

Alpharetta solar questions

Worth reading before you buy

Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Georgia electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.