Solar panels in Round Rock, TX

Roofs in Round Rock get about 1,745 hours of usable sunlight a year — more than 77% 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 Round Rock → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.

What a typical Round Rock solar system costs

A 19-panel system (7.6 kW) is about right for an average Round Rock home using 10,800 kWh a year. It would produce roughly 11,273 kWh annually and offset 100% of that usage.

How we worked this out for Round Rock

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

Step 6 matters more than it looks. Only 34% of what a system this size produces in Round Rock is used the moment it is generated; the other 7,493 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 — 8.9 years against the 9.2 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, 15.1¢/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 Round Rock gets 1,745 sun hours

That figure comes from Google's analysis of real rooftops across Round Rock — 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 Round Rock reaches about 1,793 hours, roughly 3% better than typical.

The numbers behind this page

When Round Rock actually produces

Annual totals hide the thing that catches people out: 32% of Round Rock's yearly sunlight arrives in May–July, and just 17% across November–January.

Output is unusually steady — only about 2.1× between Jun and Dec. Round Rock 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 Round Rock's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.

How Round Rock compares to the other 788 cities

What actually stands out about Round Rock:

• Plenty of roof to work with. Typical roofs here fit around 120 panels — roughly 6× what an average home needs. Roof size will not be what limits your system in Round Rock.
• Large roofs. At a median of 381 m², Round Rock has the 34th-largest typical roof footprint we've measured.

Cities with almost the same sunlight

These are the closest matches to Round Rock's 1,745 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 Texas → statewide sunlight, rates, incentives and every city we've measured.

Round Rock solar questions

Worth reading before you buy

Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Texas 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.