San Marcos, TXLocal --:--Sun now --Daylight today --
Sun on a roof in San Marcos.
The PVWatts model puts a generic roof array in San Marcos at 1,507 kWh a year for each kW of panels, using typical-year weather from a station 2.2 km away. A modeled estimate for a standard setup, not a measurement of any roof.
A year on one roof.
Scroll from January to December: the noon sun over San Marcos climbs and falls, and the modeled output follows it.
kWh per kW DC, modeled by PVWatts. Best month 151, weakest 95: a ratio of 1.59.
How San Marcos comparesderived from the figures above
Where San Marcos sits.
San Marcos ranks 96th of 157 Texas places modeled here, at the 39th percentile. Its 1,507 kWh per kW is below the Texas median of 1,518. The strongest months are July, June, August and the weakest are February, December, January; output peaks in July and bottoms out in February. In all, 29.3% of the year arrives in June, July and August, less than the 29.4% of the median place.
Closest modeled neighbors
- Kyle, 15 km northeast: 1,493 kWh per kW, 14 less than San Marcos.
- New Braunfels, 26 km southwest: 1,498 kWh per kW, 9 less than San Marcos.
- Seguin, 31 km south: 1,498 kWh per kW, 9 less than San Marcos.
- Cibolo, 43 km southwest: 1,496 kWh per kW, 11 less than San Marcos.
- Schertz, 46 km southwest: 1,502 kWh per kW, 5 less than San Marcos.
- Universal City, 50 km southwest: 1,516 kWh per kW, 9 more than San Marcos.
- Austin, 51 km north: 1,483 kWh per kW, 24 less than San Marcos.
- Converse, 53 km southwest: 1,511 kWh per kW, 4 more than San Marcos.
- Manor, 65 km northeast: 1,483 kWh per kW, 24 less than San Marcos.
Against Austin
The nearest of the six largest modeled places is Austin, 51 km to the north, at 1,483 kWh per kW. San Marcos models 24 kWh per kW (1.6%) above it. San Marcos lies 0.43 degrees of latitude south of Austin, and the sun stands higher in the sky the further south you go, which matches its higher modeled output. The two weather stations sit a similar distance from their points (2.2 km and 1.5 km), so station distance does little to explain the gap, and the weather record does the rest.
The second-nearest large place is San Antonio, 72 km southwest, where the same model gives 1,505 kWh per kW, so San Marcos runs 2 above that figure. Against the Texas median place month by month, San Marcos runs at least 2% higher in December. It runs at least 2% lower in February, August, September.
Electricity in Hays County, Guadalupe County, Caldwell CountyEIA-861
Electricity prices nearby
San Marcos is served by its own municipal utility, City of San Marcos. Municipal utilities in Texas generally sit outside retail choice, so homes in the city buy from the city utility. Its 2025 residential average was 12.73¢ per kWh, which would put the modeled 1,507 kWh at $192 per kW a year, plain multiplication and not a savings estimate.
Other providers listed in the county
- City of San Antonio: 12.4¢ per kWh, a bundled average, 888,946 residential customers across 8 counties.
- Pedernales Electric Coop, Inc: 12.75¢ per kWh, a bundled average, 420,753 residential customers across 24 counties.
- Bluebonnet Electric Coop, Inc: 11.59¢ per kWh, a bundled average, 119,030 residential customers across 14 counties.
- AEP Texas Central Company: 5.91¢ per kWh, delivery charges only, before the retail energy price, 793,896 residential customers across 44 counties.
These serve areas outside the city utility. They are the largest bundled providers, and the largest delivery-only one, whose EIA service territory lists the county. A county can list several, and which one serves a street depends on the address, so check your bill.
Modeled estimateruns in your browser
Size the array, see the kWh.
Scale the San Marcos model to another array size, take off extra losses for shade or dirt, and price the energy at any rate. It is arithmetic on the PVWatts output above, nothing more: not a quote, not a savings estimate and not advice.
Starting rate: the Texas residential average of 15.47¢ per kWh. At that rate the modeled output is worth $233 per kW a year as plain multiplication.
PVWatts v8station 671993
Month by month, per kW.
| Month | kWh per kW |
|---|---|
| January | 101.5 |
| February | 95.1 |
| March | 126.8 |
| April | 134.6 |
| May | 143.8 |
| June | 145.1 |
| July | 151.0 |
| August | 144.7 |
| September | 129.8 |
| October | 125.0 |
| November | 109.8 |
| December | 99.8 |
| Year | 1,507 |
Model assumptions
- System size
- 1 kWDC, results scale per kW
- Mount
- fixed roof mount
- Tilt
- 20°
- Azimuth
- 180°due south
- Modules
- standard
- System losses
- 14%
Location 29.87, -97.94 (San Marcos, population 74,316). Weather: typical-year data from station 671993, 2.2 km from that point.
Getting a measured number
A model cannot see your roof. Installers measure pitch, shade and the electrical panel on site. Quote marketplaces such as EnergySage, SolarReviews and WattBuy collect bids from local installers. Rate & Roof does not rank installers.
Next step
Payback, buyback.
The sliders above price the energy at one rate. The payback calculator adds the system cost and your buyback plan type, and shows every assumption. It is an estimate, not advice.
Email updatesdouble opt-in
Rates change. Get told.
One list, for Texas solar buyback plans. We write when a tracked rate changes and when new city data is published. Nothing else, and nothing until you confirm.