Method and sources
The math
Austin Energy: annual credit = the lesser of (system kW × kWh per kW × $0.1289) and your yearly electric charges (you enter them; if blank, your use × $0.1289). Net cost = kW × 1,000 × $/W − $4,000 (if checked and at least 3 kW). Payback = net cost ÷ annual credit.
PEC: production = kW × kWh per kW. Used at home = the lesser of production × your self-use share and your annual use. Exports = the rest. Grid purchases = annual use − used at home. Savings = used at home × (6.59 + 2.2546 + 2.0688)¢ + export credit, where export credit = the lesser of exports × 7.1921¢ and grid purchases × 6.59¢ (credit applies to the Base Power Charge only). Net cost = system price + $500. Payback = net cost ÷ savings.
Chart: year n = savings × n − net cost.
What is ours, not a source
- The self-use share (default 50%). Nothing we found publishes a typical figure, so it is an editable input and we show PEC payback at 10%, 50% and 100%. At the defaults that is 23.5, 19.6 and 16.3 years.
- The electric-charges cap when you leave it blank (use × 12.89¢).
- The 7 kW default system and the 15,000 kWh default use (PEC's 1,250 kWh a month example).
- The 1,300 kWh/kW default (inside Austin Energy's 1,100 to 1,500 range). Austin Energy's own 6 kW example, $1,300 a year at 12.89¢, implies about 1,680.
- We cap the PEC export credit against a full year of Base Power Charge. PEC's page does not say how credits are timed month to month, so a real bill can differ.
Where sources disagree
NATiVE Solar's page says Austin Energy residential credits reset each December. Austin Energy's own page, read the same day, says extra credit rolls over to the next month and does not mention a reset. We follow Austin Energy's page; confirm with Austin Energy before you size for credits you may not use.
What we leave out
Financing, leases, panel degradation, future rate changes, the PEC time-of-use option, batteries, the dollar value of the property tax exemption (it depends on your local tax rate), franchise fees and the monthly fixed charge. The $/W default is EnergySage's market average, not a quote.
Sources, all read October 28, 2026
| Input | Link | Checked |
|---|---|---|
| Austin Energy, Value of Solar Rate page (12.89¢ under 1 MW-AC, effective Oct 1, 2026) | austinenergy.com/green-power/solar-solutions/value-of-solar-rate | October 28, 2026 |
| Austin Energy, For Your Home (3 kW DC minimum; participating contractor; confirmation letter before install) | austinenergy.com/green-power/solar-solutions/for-your-home | October 28, 2026 |
| PEC Residential Rates (flat Base Power Charge, effective Mar 1, 2026) | mypec.com/residential-rates/ | October 28, 2026 |
| PEC Residential Rates (Delivery Charge per kWh) | mypec.com/residential-rates/ | October 28, 2026 |
| PEC Residential Rates (Transmission Cost of Service per kWh) | mypec.com/residential-rates/ | October 28, 2026 |
| PEC 2026 Rate Update (Sustainable Power Credit, effective Mar 1, 2026) | mypec.com/residential-rates/2026-rate-update/ | October 28, 2026 |
| PEC Solar and Distributed Generation (Tier I, under 50 kW AC; plus any required upgrades) | mypec.com/solar-and-distributed-generation-dg/ | October 28, 2026 |
| Austin Energy news release, Oct 22, 2026: Value of Solar up 27% effective Oct 1, 2026 (12.89¢ under 1 MW, 10.22¢ for 1 MW and larger; 6 kW example $1,000 to $1,300 a year; recalculated every three years) | austinenergy.com/about/news/news-releases/2026/Austin-Energy-increases-Value-of-Solar-rate-for-customer-owned-solar | October 28, 2026 |
| Austin Energy electric tariff FY 2026-27, Value-of-Solar Rider (effective Oct 1, 2026): monthly credits cannot exceed total electric charges; the excess carries forward | austinenergy.com/-/media/Project/Websites/shared/PDFs/Rates/Value-of-SolarRider.pdf | October 28, 2026 |
| Texas Tax Code Sec. 11.27 (2025 text): exempts the appraised value added by a solar or wind-powered energy device used primarily for on-site energy | law.justia.com/codes/texas/tax-code/title-1/subtitle-c/chapter-11/subchapter-b/section-11-27/ | October 28, 2026 |
| Texas Comptroller, Form 50-123 (file with your county appraisal district, Jan 1 to Apr 30) | comptroller.texas.gov/taxes/property-tax/exemptions/ | October 28, 2026 |
| EnergySage, Austin TX solar cost, updated Oct 23, 2026 ($2.24/W, before incentives; Austin average system 12.43 kW) | www.energysage.com/local-data/solar-panel-cost/tx/travis-county/austin/ | October 28, 2026 |
| EnergySage: federal tax credit for buyers expired at end of 2025 | energysage.com/local-data/solar-panel-cost/tx/travis-county/austin | October 28, 2026 |
Validation
Every input must be a number inside the range shown beside it. Blank, zero, negative, text and out-of-range entries show a red message and no result. Nothing is replaced behind your back.
Corrections
If a rate changed, email [email protected] with the utility page. We will check and update.