How Xcel’s time-of-use works now
Since November 1, 2025, Xcel Energy’s Colorado residential time-of-use schedule puts the on-peak window at 5–9 pm on non-holiday weekdays, year-round, with higher summer pricing June through September. Customers with smart meters are placed on it by default and can opt out to a flat rate.
The ratio is what matters: on-peak runs about 2.7 times off-peak. Dinner, laundry, the dishwasher, the EV plugged in on arrival and the air conditioner on a July evening all land in that window unless you move them.
What a battery does in those four hours
A battery fills from your solar during the afternoon, then covers the house from 5 to 9 pm. A single Tesla Powerwall 3 holds 13.5 kWh, which covers the evening peak for most homes that aren’t running central air hard. Enphase IQ Batteries and SigEnergy systems do the same job in different module sizes.
Without a battery, solar alone still helps on time-of-use: your afternoon exports offset kilowatt-hours you buy, and summer production is strong. But if your exports and your evening usage are priced differently, a battery captures the spread.
Will peak shifting pay for the battery?
Usually not by itself. A first Powerwall runs about $19,000 installed; shifting a few kilowatt-hours a day at the on-peak differential produces savings that take many years to recover that. The case gets better when you stack it with backup value, the 10% Colorado storage income-tax credit (tax years through 2026), the sales-tax exemption on residential storage, and any utility battery program you enroll in.
Our peak-shift calculator uses your actual evening usage to estimate how much of the window a battery covers. If the result is small, we’ll say so.
Free peak savings before you buy anything
Before spending money, move what you can: set the dishwasher and laundry to start after 9 pm, schedule EV charging overnight, and pre-cool the house in the afternoon. Many households trim a meaningful share of their peak usage this way. A battery makes sense for the load you can’t move.
Sources & dated facts
- Colorado residential energy storage income tax credit: 10% of purchase price, nonrefundable, tax years 2023–2026 (C.R.S. 39-22-546, SB25-026).As of Sep 23, 2026 · source
FAQ
Questions we hear
What are Xcel’s on-peak hours in Colorado?
5 pm to 9 pm on non-holiday weekdays, all year, under the time-of-use schedule in effect since November 1, 2025. Weekends and holidays are off-peak. Check your bill or Xcel’s rate page for your exact schedule and current prices.
Can I opt out of time-of-use?
Xcel lets residential customers opt out to a flat rate. If you have solar and a battery, staying on time-of-use is often better, because you can avoid the expensive hours. Without a battery, it depends on how much you use in the evening.
Does a battery sit idle when I’m on a flat rate?
On a flat rate with 1:1 net metering, shifting energy doesn’t save money, so the battery mainly serves as backup. That’s fine if backup is why you bought it, but it’s worth knowing before you choose a rate.
How many batteries do I need to cover the peak?
Most homes need one. Four evening hours of typical use without heavy air conditioning or EV charging fits in 10–13.5 kWh. Large homes, all-electric homes and summer A/C loads may need two. We size it from your interval data if you can download it from your Xcel account.