If most of your electricity runs after 9 p.m., a free hours plan can shave hundreds off your bill. If most of it runs before dinner, the same plan can add hundreds. TXU Free Nights and Weekends and Ambit Free and Clear Nights sit on opposite sides of that math: TXU throws in the whole weekend, while Ambit keeps its free window strictly overnight but stretches it to seven nights a week. Which one wins depends on one number pulled from your own smart meter, and the sections below walk that number all the way to a dollar answer using an original Free Hours Break-Even Framework.

Key takeaways

• TXU Free Nights and Weekends offers free electricity roughly 9 p.m. to 4:59 a.m. every night plus all day Saturday and Sunday, per the current TXU Energy plans page and its August 6, 2026 Oncor EFL.
• Ambit Free and Clear Nights offers free electricity 9 p.m. to 5:59 a.m. seven nights a week, per Ambit's own Free and Clear Nights launch announcement.
• A 2026 field analysis of two Dallas Fort Worth homes on Oncor by Watt Owl found real nighttime usage of only 15 to 22 percent, well below the 47 percent breakeven that specific plan required, and both homes paid $165 to $1,024 more per year than they would have on a competitive fixed rate.
• Energy portfolio analyst Greg Steagall concluded in a 2024 review that customers on a TXU Live Your Free variant generally pay more unless at least 70 percent of their kWh runs during the free window.
• You still pay TDU delivery charges of roughly 4.98 to 6.47 cents per kWh even during the free hours, per ElectricityPlans' 2026 residential TDU delivery table, so nothing on a free hours plan is actually free.
• The Free Hours Break-Even Framework in this article turns those five variables into one dollar answer per year, using only free data from Smart Meter Texas and the Power to Choose EFL for your ZIP.

What is TXU Free Nights and Weekends?

TXU Free Nights and Weekends is a time of use residential electricity plan from TXU Energy that zeroes out the energy charge portion of your bill for a set overnight window each day and for all day Saturday and Sunday. The plan is served across TXU's Oncor, CenterPoint, AEP Texas, and TNMP service areas, and the specific free-hour window and daytime rate can vary by EFL and territory, per the current TXU plans page.

The 2026 Oncor EFL for a TXU free-nights variant lists a $9.95 monthly base charge, a 12-month term, and a $150 early termination fee, per a review by ChooseTexasPower citing the August 6, 2026 EFL. Daytime energy charges on TXU free-hours products historically run in the 18 to 22 cents per kWh range, with an example as high as 26.7 cents per kWh flagged by author Enri Zhulati in the ElectricRates.org 2025 category review (published December 31, 2025, updated April 13, 2026). The exact daytime rate on your EFL is what makes or breaks the math.

The tradeoff is baked into the design. TXU gives you more hours of free electricity than any other Texas plan by adding both weekend days. In exchange, TXU sets the daytime rate high enough that a homeowner who uses most of their electricity during the workday, on a laptop, air conditioning, cooking, laundry, will pay a premium versus a straight fixed rate plan.

What is Ambit Free and Clear Nights?

Ambit Free and Clear Nights is a residential time of use plan from Ambit Energy that provides free electricity from 9 p.m. to 5:59 a.m., seven nights a week. Ambit's launch announcement states the free window is nightly and that the plan is available across Ambit Texas markets with smart meters installed.

Secondary plan summaries put the daytime energy charge on the current Free and Clear Nights 12 at 21.9 cents per kWh, a $9.95 monthly base charge, a 12-month term, and a $199 early termination fee. That daytime rate sits at the higher end of the ElectricRates.org 2025 range for free-nights plans, which is the same tradeoff every plan in this category makes: cheaper nights come from more expensive days.

The Ambit design is narrower than TXU's on hours. There is no free weekend. In exchange, Ambit's overnight window is an hour longer than the TXU 9 to 4:59 a.m. window, running until 5:59 a.m., which matters more to a shift worker or an EV charger than to a typical weekday household.

TXU Free Nights and Weekends vs Ambit Free and Clear Nights: side by side

Every figure in the table above is drawn from the current EFL or from published plan summaries. Always pull your own EFL from Power to Choose or the retailer's site and confirm the numbers for your specific ZIP code and enrollment date. Plan details, EFL availability, and credit approval apply. Rates as of August 2026.

The Free Hours Break-Even Framework: the three numbers that decide

Most head-to-head reviews stop at feature grids. This article walks the math one step further with the Free Hours Break-Even Framework, an original three-variable framework you can run on your own smart meter data before you enroll. The whole comparison collapses into a single question: what percent of your kWh runs during the free window? That number has to clear a threshold, and the threshold is not the same on both plans because the free windows are not the same size.

The framework distills the comparison to three numbers.

1. Free share, the percent of your kWh that runs during the plan's free window. You can pull this from your smart meter data at Smart Meter Texas.
2. Daytime premium, the difference between the plan's daytime kWh rate and the flat rate you would otherwise pay. If the free-nights daytime rate is 21.9 cents and a 12-month fixed plan in your ZIP is 14 cents, the premium is 7.9 cents per kWh.
3. TDU delivery still-owed, 4.98 to 6.47 cents per kWh depending on your utility per ElectricityPlans, which you owe on every kWh, free-window or not.

The breakeven is the free share that makes the daytime premium equal to the free-window savings. On a plan with a 7.9 cent daytime premium and a 14 cent baseline, that free share sits in the mid-30 to low-40 percent range for the plan itself, and closer to 47 percent once you fold in TDU delivery on your daytime hours, matching Watt Owl's field-derived 47 percent breakeven. On a plan with a wider premium (Zhulati's 26.7 cent example), the required free share climbs into the 60 to 70 percent range. Greg Steagall, a Fortune 50 energy portfolio manager writing at Energy Choice Experts, concluded in his 2024 review of a TXU Live Your Free variant that customers generally pay more unless at least 70 percent of their electricity runs during the free periods. That number is a useful worst-case guardrail for the framework.

TXU Free Nights and Weekends usually has a lower breakeven than Ambit Free and Clear Nights on the same daytime rate, because the weekend hours pull more of an average household's usage into the free window without any behavior change. That is the structural advantage TXU is selling.

How much do TDU delivery charges add during the "free" hours?

Nothing on a free-nights plan is actually free, because the TDU wires charge is separate from the energy charge and it does not go away. According to ElectricityPlans in 2026, the residential delivery charge is roughly 4.98 cents per kWh in CenterPoint territory, 6.03 cents per kWh in Oncor, 5.83 cents per kWh in AEP Texas Central, 5.67 cents per kWh in AEP Texas North, and 6.47 cents per kWh in TNMP. Competitor coverage of this plan class routinely omits that per-utility breakdown; the Framework treats it as its third variable.

A 2026 field analysis at Watt Owl put it plainly: even the "free" hours on a Dallas-area free-nights plan cost about 6 cents per kWh in TDU delivery. On 400 kWh of overnight usage in a month, that is $24 you were told was zero. Whether the plan still wins depends on how much the daytime savings on the rest of your usage outrun that delivery bill.

Why TXU Free Nights and Weekends usually wins on the clock

TXU has roughly 41 more free hours per week than Ambit does, and that structural advantage does most of the work. A typical Texas household that spends Saturday running the AC, the dishwasher, and the laundry gets to move all of that consumption into a free window without changing a single habit. The plan is friendly to weekend-heavy homes, families with kids home from school on the weekend, and remote workers whose electric load is roughly the same seven days a week.

TXU's design also handles the summer AC problem better than an overnight-only plan. Air conditioning cycles hardest in the mid-afternoon on hot Texas weekend days, and putting those hours in the free window is a real bill mover. Per the US Energy Information Administration, air conditioning is the single largest end use of residential electricity in the US and the largest single load in Texas homes during summer months, which is why the weekend savings matter more here than they would in a cooler market.

Why Ambit Free and Clear Nights can still win for pure night owls

The Ambit plan targets a specific customer: the household whose overnight window is long and predictable, and whose weekend usage is not much heavier than a weekday. An EV owner who charges every night, a shift worker on a 10 p.m. to 6 a.m. rotation, a family that runs dishwashers and pool pumps only after bedtime, all sit inside the Ambit free window.

Ambit also runs an hour longer overnight than TXU's typical 9 to 4:59 a.m. window. That extra hour, 5 a.m. to 5:59 a.m., is when many households run their coffee makers, heat their water for showers, and start dryers before the workday begins. Small change, but it is real. Over a year of 365 nights, that single extra hour adds roughly 23 free hours per month that TXU does not offer, which is the Ambit design's whole reason to exist.

The trap is easy to see. If a household picks Ambit because "free nights" sounds good, then runs its dishwashers, laundry, and pool pumps on Saturday morning like everyone else does, the 21.9 cent daytime rate quietly outruns the overnight savings.

What real Texas homes have found: the two most cited datasets

Real household data is more useful here than a marketing brochure. A 2026 field analysis of two Dallas-Fort Worth homes on Oncor by Watt Owl, published March 1, 2026, found only 15 to 22 percent of the households' actual kWh fell inside the free-nights window. On the specific free-nights plan the study compared to a competitive fixed rate, the breakeven was 47 percent nighttime use. Neither home cleared the bar.

Watt Owl's conclusion: the two homes paid $165 to $1,024 more per year on the free-nights plan than they would have paid on a competitive fixed rate. The higher figure came from the home with the lowest nighttime share and the heaviest afternoon AC load.

A parallel review by ComparePower author Graham Griffin, TXU Free Nights and Weekends: Avoid a $720 Mistake, edited by Enri Zhulati, walked a specific TXU EFL scenario and found the plan cost a modeled household $720 more per year than a fixed-rate alternative on the same annual usage. Two different independent reviews, using different homes, both landed in the $165 to $1,024 range of annual damage for the wrong household.

Academic research reaches a similar cautious view. In a Knowledge at Wharton discussion of dynamic electricity pricing, Wharton finance professor Arthur van Benthem describes a two-sided outcome: efficient time-varying prices can shift demand away from peak periods, but complicated tariff structures can backfire when customers do not fully understand them. A 2020 MIT Center for Energy and Environmental Policy Research working paper on retail rate design in a decarbonizing economy reaches parallel conclusions on time of use and critical peak pricing designs.

That is a fair summary of the free nights choice. The plans work for the households that fit them and cost the ones that do not.

What independent experts and researchers say

Five independent voices frame the tradeoff, and their views cluster in the same place: free hours plans work when the free share is well above the breakeven, and lose real money when it is not.

• Greg Steagall, Fortune 50 energy portfolio manager, Energy Choice Experts, 2024: on a TXU Live Your Free variant, customers generally pay more unless 70 percent or more of consumption runs in the free window.
• Enri Zhulati, ElectricRates.org, 2025 to 2026 update: daytime rates on free-nights products run 18 to 22 cents per kWh with examples as high as 26.7 cents per kWh, which raises the required free share the household must clear.
• Graham Griffin, ComparePower: a specific modeled TXU Free Nights household paid $720 per year more than a fixed rate on the same annual kWh.
• Watt Owl, March 2026 real-data analysis: two DFW homes on Oncor saw 15 to 22 percent night share and paid $165 to $1,024 more per year than a competitive fixed rate.
• Arthur van Benthem, Wharton, in Knowledge at Wharton: dynamic pricing can improve efficiency but complicated tariffs backfire when customers do not fully model them.

None of these five sources appears in the top-ranking competitor coverage of these plans. That is the ground the Free Hours Break-Even Framework is trying to stand on.

Which shift patterns fit which plan

• Weekend-heavy household with school-age kids: TXU Free Nights and Weekends usually wins on the weekend hours alone.
• Retired couple home most days: either plan can lose. A straight fixed rate usually wins.
• Shift worker on nights: Ambit Free and Clear Nights fits, thanks to the longer overnight window.
• EV owner charging 10 p.m. to 6 a.m. every night: Ambit Free and Clear Nights usually wins for the extra hour, but check whether the daytime rate outruns you on the rest of your usage.
• Remote worker heavy on 9 to 5 laptop and AC: neither plan tends to win. Look at a straight fixed rate instead.
• Solar owner: neither free-nights plan is designed for solar. Look at a solar buyback plan instead.

Early termination fees and other fine print

Both plans lock you in for 12 months with real teeth. TXU's early termination fee on the current Free Nights variant is $150 per the August 6, 2026 EFL. Ambit's Free and Clear Nights ETF is $199 per plan summaries. Neither is unusual for a Texas 12-month product, but neither is trivial if your free-share number ends up below breakeven and you want to switch mid-contract.

Two other fine-print items to check on each EFL:

• Base charge treatment when usage is very low. On a low-use month, a $9.95 base charge can push the effective per-kWh cost above the daytime rate you were quoted.
• Minimum usage fees. Some free-hours products carry a minimum monthly usage requirement or an escalating late payment fee. Read the "Other Key Terms" section of the EFL, and confirm the standard-service backstop with the Public Utility Commission of Texas consumer help hub.

How to run your own Free Hours Break-Even Framework

You do not have to guess at the free-share number. Every Texas home with a smart meter can pull their own hourly consumption data from Smart Meter Texas. Once you have 12 months of hourly kWh, you can slice usage into the plan's free window and the rest of the clock, and compute your real free share directly. This is the framework in five steps.

1. Register at Smart Meter Texas with your ESI ID from your current bill.
2. Download 12 months of hourly usage data as a CSV.
3. Sum kWh inside the TXU free window (Mon to Fri 9 p.m. to 4:59 a.m., plus all of Saturday and Sunday) and separately inside the Ambit free window (every night 9 p.m. to 5:59 a.m.).
4. Divide each by your annual total. Those two percentages are your free-share numbers for each plan.
5. Compare each free share against the breakeven implied by the plan's daytime rate versus a fixed-rate alternative in your ZIP, using Power to Choose for the EFL and the daytime rate. Watt Owl's real-data cases suggest a floor near 47 percent on many current free-nights EFLs, and Greg Steagall's guardrail is closer to 70 percent for plans with the widest daytime premium.

If your calculated free share sits comfortably above the plan's breakeven, the plan can save you money. If it sits below, a straight fixed rate almost always wins.

For a deeper walkthrough of how to read a free-nights EFL line by line, see The Real Cost of Free Nights Plans, and for a shortcut calculator by ZIP code see Best Free Nights Plans in Texas by ZIP Code. If you want to check whether the plans available at your address include a free-nights option worth running through this test, our Free Nights Plan Calculator is the fastest way in. And if you are new to how Texas retail electricity even works, How Texas Deregulated Electricity Works is the primer.

Frequently asked questions

What time do the free hours start on TXU Free Nights and Weekends?

The current 2026 TXU free-nights EFL for Oncor territory lists free electricity from 9 p.m. through 4:59 a.m. daily, plus all day Saturday and Sunday. The exact window can vary by EFL edition and TDU service area, so always confirm on the EFL for your ZIP code at Power to Choose before enrolling.

What time do the free hours start on Ambit Free and Clear Nights?

Ambit's launch materials state free electricity from 9 p.m. to 5:59 a.m., every night of the week. That is one hour longer than the typical TXU overnight window and applies seven nights a week, but there is no free weekend on this Ambit plan.

Is TXU Free Nights and Weekends worth it?

It depends on your free share. TXU's plan usually needs your household to run at least 40 to 50 percent of its electricity during the free window to beat a competitive fixed rate, and closer to 70 percent when the daytime premium is at the high end of the range. Weekend-heavy households often clear that bar without changing habits. Weekday-heavy households usually do not, per the modeled $720 annual delta in ComparePower's review.

Is Ambit Free and Clear Nights worth it?

It works for households whose usage is heavily overnight and whose weekends are not much busier than weekdays. Shift workers, overnight EV chargers, and households on strict overnight run schedules are the ones who tend to save. A typical family with heavy Saturday and Sunday usage often does better on a plan that includes the weekend.

Do you still pay TDU delivery charges during the "free" hours?

Yes. The TDU wires charge, 4.98 to 6.47 cents per kWh depending on which utility delivers your power per ElectricityPlans, applies on every kWh you use. The plan zeroes out the retailer's energy charge for that window but not the TDU's delivery charge, per the 2026 Watt Owl field analysis.

Which plan has the lower early termination fee?

TXU's Free Nights variant lists a $150 ETF on its August 6, 2026 EFL for Oncor. Ambit Free and Clear Nights lists a $199 ETF in plan summaries. Both are 12-month contracts. Neither is a soft exit if you decide mid-contract the plan does not fit.

Ambit Energy is a home-based business opportunity and a licensed retail electricity provider in Texas. Earnings vary. Individual results and household savings vary. All plans are subject to credit approval and to the terms of the current Electricity Facts Label for your service area.