The Three-Variable Problem Most Customers Miss
Every residential electricity bill in Texas is the product of a simple equation: kilowatt-hours (kWh) used, multiplied by an effective rate per kWh, plus fixed fees that sit there regardless of consumption. Providers and their marketing materials tend to advertise the middle variable while burying the third one and leaving you to figure out the first on your own.
When a bill comes in higher than expected, the diagnostic question is not “is my provider ripping me off” (though that is sometimes the answer). The right question is: which of the three variables moved, and by how much?
This guide runs through each variable with enough specificity that you can open your actual bill and locate the number being discussed. It also covers peak hours for electricity and how to weatherize your home, because those two levers are the most direct tools a residential customer controls.
Variable 1: Kilowatt-Hours Consumed
What your bill should show you
Every Texas bill is required by the Public Utility Commission of Texas (PUCT) to include a usage graph covering at least the prior 12 months. If yours does not have this, that is a billing compliance issue worth noting. The graph is the fastest way to see whether your current month is an anomaly or part of a trend.
A typical 2,000-square-foot Texas home uses roughly 1,100 to 1,400 kWh in a mild spring month and 2,000 to 2,800 kWh in July or August, depending on thermostat settings, insulation quality, and home age. If your summer bill is showing 3,500 kWh or more, the usage itself is the story.
The HVAC factor
Heating, ventilation, and air conditioning accounts for 50 to 60 percent of a Texas home’s electricity consumption in summer, according to the U.S. Energy Information Administration’s residential survey data. A unit running continuously rather than cycling is the single most common cause of an unexplained usage spike. A system that ran 10 hours per day in June but runs 16 hours per day in July will produce roughly a 60 percent increase in HVAC-related consumption alone.
Other high-draw appliances worth checking against your usage timeline:
- Electric water heaters: 4,000 to 5,000 watts per hour of operation.
- Pool pumps: 1,000 to 2,500 watts, often set to run on timers that customers forget to adjust seasonally.
- Electric dryers: 5,000 watts per cycle.
- A second refrigerator in a garage: 100 to 400 watts continuously, meaning 72 to 288 kWh per month for doing nothing but sitting there.
How to isolate the cause
If your provider offers a smart meter data portal (and all Texas providers operating on the ERCOT grid do, because Oncor, AEP, CenterPoint, and the other transmission and distribution utilities (TDUs) have deployed advanced meters statewide), download your hourly usage data. Look for the hours between 2 p.m. and 8 p.m. in summer. If consumption is spiking sharply during those windows, HVAC and peak-hour pricing are interacting, which leads directly to Variable 2.
Variable 2: Your Effective Rate Per Kilowatt-Hour
Advertised rate versus effective rate
Texas REPs are required to publish an Electricity Facts Label (EFL) for every plan. The EFL lists a price per kWh at three usage levels: 500 kWh, 1,000 kWh, and 2,000 kWh per month. These three numbers are not the same, and the difference is not accidental. Many plans include bill credits that only trigger above a certain threshold, making the 2,000 kWh rate look more attractive than the 500 kWh rate.
If you used 1,650 kWh last month, you are probably paying a blended rate that sits between the 1,000 kWh and 2,000 kWh figures. To find your actual effective rate, divide your total bill (after removing TDU delivery charges, which are set by the utility, not your REP) by your kWh consumed. That number is your true cost per kWh.
For context, the average Texas residential retail rate as of early 2025 sits around 12 to 14 cents per kWh (effective rate, including fixed charges spread across consumption). A plan that looked like 11 cents on the EFL at 2,000 kWh may actually be costing 13.5 cents at your 1,400 kWh actual usage because the bill credit did not trigger.
Time-of-use plans and peak hours for electricity
Time-of-use (TOU) plans are increasingly common among Texas REPs, and they are worth understanding before signing one. Under a TOU structure, the rate per kWh is not flat. It varies by hour.
Peak hours for electricity in Texas typically run from noon to 8 p.m. in summer, with the most expensive window usually falling between 3 p.m. and 7 p.m. This aligns with ERCOT’s systemwide demand peak and with when solar generation starts to decline while air conditioning load remains high. Some TOU plans charge two to three times the off-peak rate during this window.
A customer on a TOU plan who is running the dishwasher, dryer, and oven between 5 p.m. and 7 p.m. is paying a premium for every one of those kWh. Shifting those loads to after 9 p.m. or before 10 a.m. can produce a 15 to 30 percent reduction in the electricity portion of the bill, depending on how pronounced the plan’s peak-to-off-peak spread is.
The math: if your TOU plan charges 18 cents/kWh during peak and 9 cents/kWh off-peak, and you use 400 kWh per month during peak hours, moving 300 of those kWh to off-peak saves (300 x $0.09) = $27 per month. Over a Texas summer (June through September), that is $108.
Plan mismatches worth flagging
A fixed-rate plan with a low advertised rate at 2,000 kWh is not well-suited to a customer who consistently uses 900 to 1,200 kWh. The bill credit threshold is never reached, the effective rate is higher than the headline, and a different plan structure would serve the actual usage pattern better. LightCompanies profiles individual providers with usage-tier breakdowns for exactly this reason.
Variable 3: Fixed Fees and TDU Delivery Charges
What you cannot negotiate away
Regardless of your provider, a portion of your bill is set by the TDU serving your area. Oncor covers the Dallas-Fort Worth region. CenterPoint covers Houston. AEP covers West Texas and parts of the coast. These are regulated utilities with rates approved by the PUCT.
TDU charges typically include a fixed monthly customer charge (ranging from roughly $3 to $10 depending on the utility) plus a per-kWh delivery charge (ranging from roughly 3 to 6 cents/kWh in recent rate cases) plus occasionally a transmission cost recovery factor. These numbers are published and available on each TDU’s website, but most customers have never looked them up.
For a customer using 1,200 kWh on Oncor’s system, TDU charges alone can account for $55 to $75 of the total bill before the REP’s energy charge enters the picture. This is not a REP billing error. It is a regulated component, and switching providers does not reduce it.
REP-specific fixed fees
Some REPs add their own fixed monthly fees on top of TDU charges. These range from $0 to $15 depending on the provider and plan. A $9.95 monthly base charge spread over 600 kWh of actual usage adds 1.66 cents per kWh to your effective rate. That is not trivial. It is the difference between a competitive plan and a mediocre one at lower usage tiers.
How to Weatherize Your Home to Reduce Consumption
Weatherization is the only lever that reduces Variable 1 (consumption) without changing behavior. The upgrades below are ranked by typical payback period for a Texas home, from shortest to longest.
Air sealing: shortest payback, most overlooked
Texas homes lose a significant share of conditioned air through gaps around recessed light fixtures, plumbing penetrations, attic hatches, and door frames. The Department of Energy estimates that air leakage accounts for 25 to 40 percent of heating and cooling losses in typical residential construction. Sealing these gaps with caulk, spray foam, or weatherstripping costs $50 to $300 in materials for a DIY project and can reduce HVAC runtime meaningfully.
A home that drops from 2,400 kWh in August to 2,000 kWh through air sealing saves approximately $48 to $56 per month at a 12 to 14 cent effective rate. Payback on a $200 material investment: roughly four summer months.
Attic insulation
Texas building codes historically permitted lower insulation R-values than northern climates require. Many homes built before 2000 have attic insulation at R-19 or less. The current IECC standard for Climate Zone 2 (Houston, South Texas) recommends R-38, and Climate Zone 3 (Dallas, Austin) recommends R-49.
Adding blown-in insulation to bring an attic from R-19 to R-38 costs roughly $1,000 to $2,500 for a 2,000-square-foot home, depending on contractor and access conditions. HVAC savings of 10 to 20 percent are typical. At 2,000 kWh summer usage and a 13 cent effective rate, a 15 percent reduction is 300 kWh per month, or $39 per month. That pencils out to a two-to-five-year payback, which is competitive with most home improvement investments.
Thermostat strategy during peak hours for electricity
A programmable or smart thermostat set to pre-cool the home before peak hours begin reduces compressor runtime during the most expensive pricing window on TOU plans. Setting the thermostat to reach 73 degrees by noon and then allow drift to 76 degrees by 4 p.m. (before cooling again in the evening) can shift a meaningful share of HVAC consumption out of peak hours. This is not about comfort sacrifice. It is about timing the same total cooling load differently.
Window film and shade
Solar heat gain through west- and south-facing windows is a meaningful load driver in Texas summers. Reflective window film applied to these exposures can reduce solar heat gain by 50 to 70 percent. At roughly $4 to $8 per square foot installed, this is a longer-payback investment than air sealing or insulation but worthwhile for homes with large single-pane or low-performance double-pane glass.
Putting the Diagnosis Together
If your bill is higher than expected, work through this sequence:
- Pull your 12-month usage graph from your bill or provider portal. Identify whether this month is an anomaly or a trend.
- Download hourly data from your smart meter portal. Flag whether consumption spikes align with peak hours for electricity (noon to 8 p.m. in summer).
- Calculate your effective rate per kWh by dividing the energy-only charges (strip out TDU delivery charges) by your kWh consumed. Compare this to the EFL rate at your actual usage level.
- Check whether your plan’s bill credits or TOU structure are working for or against your usage pattern.
- If usage is the driver, prioritize air sealing and attic insulation before any other investment. Both weatherize your home against the specific climate conditions Texas presents.
Provider switching may not solve a problem caused by high consumption. But if the effective rate analysis shows you are paying materially above what comparable plans charge at your usage tier, that is a separate and correctable issue. LightCompanies maintains provider profiles with effective rate comparisons by usage band to help readers make that determination without doing the full research from scratch.
The billing system in Texas gives customers more choices than most U.S. markets. That cuts both ways. More choice means more opportunity to find a plan that fits actual usage patterns. It also means more opportunity for a plan mismatch to go unnoticed for months.