A rooftop array produces most of its energy in the middle of the day, when many households use the least. The surplus flows back onto the grid. What you get for it is the most consequential and least understood variable in residential solar economics, and in Texas it depends on which utility serves your address and which retail plan you are on.
Three different arrangements
True net metering. The meter runs backward. Every exported kilowatt-hour offsets an imported one at the same retail rate, and you settle on net consumption. This is the most favorable arrangement and it is not universal.
Net billing, or a buyback credit. Imports and exports are measured separately. You pay retail for what you import and receive a credit for what you export, and the credit is lower than the retail rate. The gap between those two numbers is the whole story. A plan paying 4 cents for exports while charging 15 cents for imports gives exported energy roughly a quarter of the value of self-consumed energy.
No compensation. Some plans credit exports at zero. Exported energy is simply given away. This is rare but it exists, and it is a catastrophic pairing with an oversized array.
Why neighbors get different answers
In Texas, two things vary independently. The transmission and distribution utility that owns the wires to your house is fixed by geography. The retail electric provider that sells you energy is your choice in most of the deregulated market, and each provider sets its own solar buyback terms.
Municipal utilities and electric cooperatives are outside the deregulated market and run their own programs entirely, with their own credit rates, their own caps, and sometimes their own rebates. So a house served by a co-op and a house four miles away served by a competitive retailer genuinely have different solar economics, and neither neighbor is misinformed.
The questions that determine your credit
Before signing anything, get written answers to these about the specific plan you intend to be on after installation:
- What is the export credit rate, in cents per kWh, and is it fixed or indexed to a wholesale price?
- Do credits roll over month to month? If so, do they expire annually, and do you ever receive cash for an unused balance or is it simply forfeited?
- Is the credit applied only to the energy portion of the bill, or does it also offset delivery charges and the fixed monthly customer charge?
- Is there a monthly minimum charge or a solar-specific fee?
- What is the contract term, and what happens to the buyback rate at renewal?
That last question deserves weight. Buyback plans are commonly offered on twelve or twenty-four month terms while the solar asset lasts twenty-five years. Model what happens if the credit rate at renewal is materially worse than today's, because over the life of the system it probably will be at some point.
Self-consumption beats export
When export credits are below retail, every kilowatt-hour you use inside the house at the moment it is produced is worth more than one you send out. That changes household behavior in ways that are cheap and effective:
- Run the dishwasher, laundry, and pool pump in the middle of the day rather than the evening.
- Pre-cool the house in the early afternoon so the air conditioner runs less during the evening peak.
- Charge an electric vehicle during daylight when the car is home.
These are not marginal. On a net billing plan with a wide spread between import and export rates, shifting a few large loads into the production window can move annual savings by a noticeable percentage without any equipment at all.
Where batteries fit
A battery stores midday surplus for evening use, which converts low-value exports into high-value self-consumption. Whether that pays depends entirely on the spread. With true net metering and a full retail credit, a battery adds little economic value and is bought for backup power. With a wide import-export spread or time-of-use pricing, the arithmetic is much more favorable.
Separate the two motivations when you evaluate a quote. Backup power during an outage has real value to many households and it is a legitimate reason to buy a battery. It is a different reason from bill savings, and a proposal that blends them is harder to check.
Interconnection comes first
You cannot legally export anything until the utility approves interconnection and installs or reconfigures the meter. The installer normally files this, but ask who is responsible, what the current processing time is, and whether the system will be allowed to operate before approval. Systems have sat dark on roofs for weeks waiting on paperwork nobody was tracking.
Put the assumption in writing
Whatever export rate a savings projection assumes, ask for it to be stated explicitly in the proposal, in cents per kWh, alongside the retail rate it is compared against. A projection with both numbers on the page can be verified against your utility's published tariff. A projection that shows only a savings total cannot be checked by anyone, including the person who printed it.