How much could plug-in solar save in Texas?
A small system will not erase a Texas electric bill. It can reduce the electricity a home buys during sunny hours—and the low upfront cost can make the payback surprisingly practical.
A well-positioned 400 W system is estimated to produce about 550 kWh per year. At $0.16/kWh and 90% use inside the home, that is about $79 in first-year savings.
Illustrative starting estimates
| System | Estimated kit | Annual production | First-year savings | Simple payback |
|---|---|---|---|---|
| 400 W | $499 | 550 kWh | $79 | 6.3 years |
| 800 W | $749 | 1,100 kWh | $158 | 4.7 years |
| 1,200 W | $999 | 1,650 kWh | $238 | 4.2 years |
Illustrative Houston-area assumptions: south-facing, little shade, $0.16/kWh electricity, 90% of production used in the home, estimated hardware-only kit prices, and no value assigned to exports. Mounting, shipping, export controls, and professional electrical work are excluded.
The basic calculation
The most valuable solar electricity is usually the electricity your home uses immediately. If generation exceeds the home’s demand, the financial treatment of that excess depends on the equipment, retail plan, meter, utility, and applicable rules. The calculator conservatively assigns exported plug-in solar electricity no value.
Why larger is not automatically better
Larger kits can cost less per watt, improving the apparent payback. But a larger system is also more likely to produce more than the home is using at a particular moment. A smaller system may keep a higher share of its production behind the meter, especially in an apartment or an efficient home.
What changes the result most
- Orientation and shade: clear southern exposure generally produces more than a shaded or north-facing location.
- Your electricity price: each kilowatt-hour avoided is worth roughly the retail rate you would otherwise pay.
- Daytime household demand: higher self-use generally makes more of the production valuable.
- Total installed cost: mounting, wiring checks, sensors, or other requirements can materially extend payback.
- Weather and degradation: production changes from year to year, and panels gradually lose output over time.
Open the adjustable Texas calculator →
Primary sources and method
- NREL PVWattsA public model for estimating photovoltaic production by location and system assumptions.
- U.S. EIA electricity prices by stateMonthly residential electricity-price data; use your actual bill rate when available.
- Texas Plug-In Solar calculator methodFull V1 production, price, degradation, and export assumptions.