My electric bill doubles every August in Texas. Where is the heat getting in?

What does a summer electric bill Texas homeowners see in August actually pay for?

Start with the one number that is genuinely verified. The U.S. Energy Information Administration's Table 4 puts the average Texas residential electricity price at 14.94 cents per kWh for 2024. That is a statewide annual average across all providers and plans, not a rate you personally pay, but it is a defensible anchor.

Now the assumption, and this is ours, not the EIA's. Say a house uses 1,200 kWh in a mild April month and 2,400 kWh in August. Those are illustrative figures we chose to make the arithmetic visible. The EIA does not publish a DFW household bill total, and we are not going to invent one and put their name on it.

Run the multiplication:

• April: 1,200 kWh × $0.1494 = about $179
• August: 2,400 kWh × $0.1494 = about $359
• The difference, 1,200 kWh, is about $179 of estimated added cost for that one month
• Every additional 100 kWh, whatever your baseline, is $14.94

All four of those are estimates derived from the EIA rate, not EIA-published bill figures. The useful part is not the dollar total. It is the conversion factor. Once you know that 100 kWh is roughly fifteen dollars, every efficiency claim you read becomes checkable. A measure that saves 20 kWh a month is saving you three dollars a month, no matter how it is advertised.

How do I get my own numbers instead of using yours?

Your own bill is better data than any average, and it takes about ten minutes to pull.

1. Find kWh, not dollars. Every bill shows usage in kilowatt-hours somewhere, usually near the meter reading. Dollars mix in delivery charges, base fees and plan quirks. kWh is the physical quantity.
2. Pick your shoulder month. April or October, when the system barely runs, is your baseline load: refrigerator, water heater, lights, everything that is not cooling.
3. Subtract. August kWh minus shoulder-month kWh is a rough estimate of your cooling load for that month. It is rough because pool pumps and longer daylight muddy it, but it is close enough to make decisions with.
4. Multiply by your actual rate. Divide last month's total charges by last month's kWh to get your real all-in cents per kWh, including delivery. It will usually land above the 14.94 cent statewide average, because that average excludes nothing but also reflects plans cheaper than most people are on.

Do this for three summers if you have the history. One hot year will make any fix look brilliant and one mild year will make it look useless. The National Weather Service recorded 55 days at or above 100°F at DFW Airport in 2023 and roughly six or seven in 2025. A house that did nothing at all between those years still saw a very different August.

Which fix returns the most per dollar spent?

Ranked honestly, using only figures that trace to a published source. Where no verified savings number exists, we say so rather than filling the gap.

1. Shade the outdoor condenser. The Arbor Day Foundation states that shading the air conditioning unit itself can cut its electricity use by up to 10 percent. This is close to free if you already have something that can shade it without restricting airflow around the coil. Nothing else on this list has that ratio.
2. Attic air sealing, $200 to $600. No verified percentage exists that we are willing to publish, and we are not going to make one up. What the attic cost guidance does say is that air sealing usually returns more than adding insulation depth past R-38, which is a ranking statement rather than a savings figure.
3. Attic insulation top-up, $300 to $800 for a 1,500 square foot attic going from R-38 to R-49.
4. Attic radiant barrier, $350 to $2,700. HomeGuide gives 5 to 10 percent cooling savings and, separately, 10 to 20 kWh a month. Those two figures do not reconcile. At 14.94 cents, 10 to 20 kWh is $1.49 to $2.99 a month, while 5 to 10 percent of a 1,200 kWh cooling delta is $9 to $18 a month. Plan on the low end and be pleasantly surprised.
5. Shade trees. Up to 35 percent of summer cooling cost, per Arbor Day, for large deciduous trees on the east, west and northwest sides. The catch is time, and we could not verify how many years it takes to get meaningful canopy, so we will not guess.

Why does the attic usually beat the windows on payback?

Two reasons, and both are about area.

A typical DFW house has far more ceiling than glass. A 2,000 square foot single-story home has roughly 2,000 square feet of ceiling separating conditioned space from an attic that runs punishingly hot on a July afternoon. The same house might have 250 to 350 square feet of glass. Even if a square foot of glass admits more energy than a square foot of insulated ceiling, the ceiling has six to eight times the area working against you.

The second reason is that attic work fixes a defect while glass treatment reduces a design feature. An attic at R-19 in a Zone 3A climate is under-built, and bringing it to code depth is recovering performance the house should already have had. Windows facing west are doing exactly what glass does. You are not repairing a fault, you are reducing a load, and reductions cost more per unit of effect than repairs do.

There is a third practical reason that does not show up in payback math. Attic work is invisible. You will never look at it, never clean it, never have an opinion about how it changed the room. Every dollar goes to the energy result. That makes it the right first move on pure economics, and also the reason people put it off for years in favor of things they can see.

If your budget only stretches to one project this year and the criterion is dollars, seal and insulate the attic. That is the honest ranking even from a window film company.

So where do the windows actually cost me money?

They cost you real money, just less than the marketing usually implies and more than the skeptics assume.

The Department of Energy's long-standing guidance is that heat gain and loss through windows accounts for roughly 25 to 30 percent of residential heating and cooling energy use. That is a national figure across all housing stock and all orientations, so treat it as a scale marker rather than a prediction for your house. Applied loosely to the estimated $179 of added August cost in our example, glass would be responsible for somewhere in the range of $45 to $54 of it.

Your own share depends on things you can look at directly:

• Orientation. West and southwest glass carries most of the afternoon load. North glass carries almost none.
• Area. A wall of sliding doors is a different problem from two bedroom windows.
• Existing glass. Single-pane clear glass admits far more than a modern low-E double-pane unit already does.
• Shading. A deep porch, a neighbor's two-story, or a mature tree may already be doing the work.

If your glass is mostly north-facing, already low-E, and shaded by a porch, the honest answer is that windows are not where your August money is going, and you should spend it in the attic. If you have 120 square feet of west-facing single-pane glass over a tile floor, glass is a serious line item and worth treating.

Does window film pay for itself?

We are not going to publish a payback period, because we do not have a verified one, and any company that quotes you a confident number without measuring your glass is guessing.

Here is what can be stated from published specification. 3M's Prestige Series technical data sheet lists total solar energy rejection between 50 and 62 percent at normal incidence depending on the model, and as high as 66 percent when the sun strikes the glass at 60 degrees, which is close to the geometry of a late Texas afternoon. The line spans 21 to 69 percent visible light transmission, and the film contains no metals.

What that converts to in dollars depends on your glass area, orientation, existing glazing, electricity rate and how cold you keep the house. Multiply those five variables together and the honest range of outcomes is wide enough that a single advertised payback figure is meaningless.

The other half of the answer is that energy is not the only return. Film reduces the afternoon glare that drives people out of a room, and it blocks a minimum of 99.9 percent of UV, which is the part of the return that shows up as furniture and flooring that has not faded. Whether that counts as paying for itself depends on whether you value those things, which is your call and not something we can put in a spreadsheet. If your only criterion is dollars per dollar, the attic still goes first. Our sun control film pages list the specs so you can do your own math.

Can I just shop for a cheaper rate instead?

In most of the ERCOT service area you can, and it is worth an hour of your time before you spend anything on the building. Reducing the price of every kWh applies to your whole bill at once, including the two-thirds that has nothing to do with cooling.

Two cautions. First, plan pricing in Texas is frequently structured around usage tiers and bill credits that trigger at specific monthly totals. A plan advertised at an attractive average rate at 2,000 kWh can be poor value at 900 kWh, which means the plan that suits your August may be a bad fit for your April. Read the electricity facts label at three usage levels, not one.

Second, rates move. The EIA figure of 14.94 cents per kWh is the 2024 Texas annual average. A third-party tracker citing EIA, ERCOT and PUCT methodology put the Texas residential rate at roughly 16.11 cents per kWh as of April 2026, which is a secondary source and a directional signal rather than a number to build a contract around. At 16.11 cents, the same 1,200 kWh August difference in our example works out to about $193 instead of $179.

Context for why summer pricing behaves the way it does: ERCOT's all-time summer peak demand record is 85,508 MW, set on August 10, 2023. Your August bill and the grid's worst afternoon are driven by the same weather, at the same hour, across several million households at once.