Fixed vs Variable in a Texas Summer: What You're Really Betting On
A fixed-rate plan locks your per-kWh energy charge for the contract term, so a Texas heat wave cannot raise your rate mid-contract. A variable-rate plan resets every billing cycle with wholesale market prices, which can fall in mild months and climb during high-demand stretches. Fixed buys certainty. Variable trades that certainty for the chance of a lower month.
A fixed-rate plan and a variable-rate plan can carry similar headline numbers in June and finish the summer hundreds of dollars apart. The difference is not the rate you start with. It is who absorbs the risk when demand climbs on the hottest weekday afternoon of the year. In a Texas summer that question stops being academic, because the month your rate is most likely to move against you is the same month your air conditioner is working hardest.
What Fixed and Variable Actually Buy You
A fixed-rate plan locks your energy charge, the price you pay per kWh, for the entire length of your contract. Sign a 12-month fixed plan and that per-kWh number does not move, no matter what happens on the grid in July. A variable-rate plan, sometimes called a month-to-month or index plan, resets your rate every billing cycle based on what ERCOT's wholesale market is doing that month. Say your usage lands at the Texas average of 1,094 kWh a month (EIA, 2026). At a fixed 16.44¢/kWh, that's 1,094 × $0.1644 = $179.85 in energy charges before any base fee or delivery charge. Under a variable plan, that same 1,094 kWh could price lower in a mild spring month or considerably higher in a heat-wave month, because the rate itself is not locked.
Why a Texas Summer Sharpens the Bet
Texas runs a mostly deregulated wholesale electricity market. When demand climbs toward the grid's limit on a hot afternoon, wholesale prices can climb with it, and ERCOT, the operator of the Texas grid, periodically asks homes and businesses to cut usage during those stretches. A fixed-rate plan insulates you from that entirely: your contracted rate holds no matter what the wholesale market does that day. A variable-rate plan passes the swing straight through to your bill. The exposure grows with how much power you use during exactly the hours prices move, and Texas summer usage is not small. Our city estimates put Katy around 1,500 kWh a month, the highest figure in our data, and Houston around 1,420 kWh. High summer usage and a floating rate are a combination worth thinking through before you sign anything.
Here is the asymmetry nobody walks you through at signup. A fixed-rate plan caps your downside and your upside at the same number. A variable plan leaves both open, and the month most likely to move against you is the month you use the most power. In Texas that is August, when the grid is tightest and your air conditioner runs hardest. The bet is not symmetric, because the high usage and the high price tend to arrive together.
The Fixed-Rate Trap Hiding in the EFL
Every retail electricity plan in Texas comes with an Electricity Facts Label, or EFL, a standardized one-page disclosure every provider is required to give you. It shows the rate type, the contract term, and a table of average prices at 500, 1,000, and 2,000 kWh of usage. Here is the trap: a plan's advertised average price is built around those three tiers, and your household's real usage rarely lines up neatly with any of them. A summer household running 1,420 kWh or 1,500 kWh, around where our estimates put Houston and Katy, can land in a very different price bracket than the 1,000 kWh column most people glance at. The other line to read carefully is the early termination fee, or ETF, the charge for breaking a fixed contract before its term ends. Variable plans typically skip this fee since there is no term to break, but that flexibility is the flip side of the price protection you are giving up.
Don't judge a fixed plan by the 1,000 kWh row on the EFL alone. Across 159 distinct bills uploaded to Voltcheckr over the last 90 days, the median came in at $296.86 while the average was $343.81, a spread wide enough to show how differently real households use power. Check the average price at the usage level closest to your own bill, and read the early termination fee line before you sign a multi-month contract.
- •Is my usage stable month to month, or does it swing hard with the thermostat? Pull your last few bills and compare.
- •What does the EFL's average price table show at my actual usage level, not just the 500 or 1,000 kWh column?
- •What's the early termination fee, and how many months are left if I need to break the contract early?
- •Do I have any hedge against a spike, like solar, a smaller home, or a habit of cutting usage during conservation alerts?
- •Can my budget handle a bad month if wholesale prices jump during the next ERCOT conservation appeal?
If your summer usage runs above the Texas average of 1,094 kWh a month, and our city estimates put Houston around 1,420 kWh and Katy around 1,500, a fixed rate through August removes the single biggest unknown: what wholesale prices do on the hottest weekday afternoon of the year. Save the variable gamble for a season when your usage and the grid aren't both maxed out at once.
A fixed rate and a variable rate are two different bets on the same summer. See which fixed and variable plans are actually available for your address today, side by side, before you lock in either one.
Compare Today's RatesFrequently asked questions
A fixed-rate plan holds your energy charge steady for the length of your contract, usually 6 to 36 months. A variable-rate plan changes your per-kWh charge every billing cycle based on the wholesale electricity market that ERCOT, the Texas grid operator, runs, so your rate can move with no warning.
For most households, yes, because it removes the risk of a wholesale price spike during a summer heat wave. It is not automatically the cheapest option, but it is the more predictable one.
Yes. In months when wholesale prices are low, a variable plan can price below a comparable fixed plan. The trade-off is that during high-demand summer afternoons, the same plan can price well above it, and you won't know which month you're getting until the bill arrives.
An early termination fee (ETF) is a charge for canceling a contract before its term ends. It's built into most fixed-rate agreements but rarely appears on variable, month-to-month plans, since those don't lock you into a term in the first place.
Check the Electricity Facts Label, or EFL, that came with your enrollment. It states the rate type plainly near the top, along with the contract term and any early termination fee.