Why Your Power Company Charges More at Dinnertime

Wednesday, August 19 · 6 min read

Your electric bill isn't one flat number behind the scenes, even if the total on the page looks like it. If your utility offers a time-of-use plan, the same kilowatt-hour costs different amounts depending on the hour you use it, and dinnertime is usually the most expensive hour of the day to run anything.

Reply and tell us if you already know your own utility's peak hours off the top of your head.

Electricity doesn't cost the same to generate at every hour of the day, and on a time-of-use (TOU) rate plan, your utility passes that difference straight to your bill.

The mechanism is straightforward: demand on the grid spikes in the early evening, when people get home, run the AC or heat, cook dinner, and switch on lights and screens all at once. Utilities have to keep enough generation and delivery capacity ready for that peak, even though it only lasts a few hours a day, and TOU pricing is how they recover that cost and nudge some of the demand elsewhere.

The typical shape, and it varies by utility, is three tiers:

The U.S. Energy Information Administration tracks time-varying rate plans like this as part of a broader shift toward pricing that reflects real-time grid demand rather than a single flat rate.

Not every utility offers TOU (time-of-use) pricing, and not every utility that offers it makes it the default plan, so the first step is confirming you're on one at all. Your last bill or your utility's account portal will say which rate plan you're on.

If TOU is available but you're not on it, the same portal will show the exact peak and off-peak hours and the price difference for your specific plan and region, and that number is worth finding, because it's the one that tells you whether moving a load is worth the hassle.

Once you know your hours, the move is simple: nothing changes about how much electricity you use, only when. A dishwasher, a load of laundry, an EV charging overnight instead of the moment you plug in, these are all loads that don't care what time they run, so shifting them out of the peak window costs you nothing but a short delay.

Note: many EVs allow you to schedule charging.

The savings from doing this once are rarely dramatic. Shift the right two or three loads consistently, though, and it adds up over a full billing cycle, especially in a household running an AC, a dishwasher, and a load of laundry through the same few peak hours most evenings.

Every electric bill hides two separate charges inside one number, and knowing which is which is the difference between understanding your bill and just paying it.

In a lot of states you can shop for your supply from a different company while your same utility still handles delivery, which is why some bills show two company names. Even if you can't shop around where you live, splitting the number in your head still matters, because delivery charges are largely fixed. They don't move much no matter how little electricity you use. Supply is the part that responds to a TOU plan, to how much you run the AC, to everything actually within your control day to day.

Then there's the fixed charge, sometimes called a customer or basic service charge: a flat fee you pay every month just for being connected, before a single kilowatt-hour is counted. It's usually a small line near the top of the bill, easy to miss, and it's the reason your bill never hits zero even in a month you barely use power at all.

Reading the bill this way changes what you look at when it goes up. A rising bill from a supply-and-usage problem is fixable with the moves in this issue. A rising bill from a delivery-rate increase, which utilities file for and get approved through their state regulator, isn't something a TOU plan or a smarter dishwasher schedule touches at all, and it's worth knowing the difference before you blame your own habits for a rate hike.

Every house has a baseline of power draw that never stops: chargers, a cable box, a router, a second fridge in the garage. Most people have no idea how much it adds up to until they measure it.

The tool for this is a plug-in power meter. Plug the meter into the outlet, plug the device into the meter, and it reads exact watts in real time. A Kill A Watt meter is the standard tool for this job: leave it running for a full day and it totals the kilowatt-hours too, not just the instant reading.

Go outlet by outlet through the always-on stuff: the TV and everything plugged into it, the office setup, the garage fridge, any charger left in the wall with nothing attached. A phone charger with nothing plugged into it draws almost nothing, but a cable box or an older game console left "off" can pull ten to twenty watts around the clock, every hour of every day, in use or not.

Add up five or six of those and you've found a real, permanent line on your bill that has nothing to do with time-of-use pricing at all, and everything to do with gear that never actually powers down. Once you know which outlets are worst, a simple smart plug or a power strip with a real off switch solves most of them without changing a single habit you already have.

Most dishwashers and a fair number of washing machines built in the last decade have a delay-start button, and it's one of the few free pieces of home automation already sitting on your appliance. Load it, set the delay, and it starts on its own hours later, no app, no subscription, no smart-home setup required.

If you're on a time-of-use plan, this is the easiest single change in this issue. Load the dishwasher after dinner like normal, but instead of starting it right away, set the delay for whenever your off-peak window begins, then walk away. Same dishes, same detergent, same cycle, a lower price for every one of them.

The button is usually labeled plainly, "Delay Start" or "Delay Wash," near the start button itself, sometimes requiring you to hold it or press it a set number of times to add hours. If you've never used it, the manual for your model has the exact steps, and it's worth the two minutes to find out, because once it's set, it's set. You don't have to remember to use it again after the first time. It becomes part of loading the dishwasher.

If the plug-in meter above sounds like the right idea but more hassle than you want to commit to, the SwitchBot Plug Mini (US) does the same job permanently, on one device, all the time.

Plug it into the wall, plug your device into it, and the SwitchBot app tracks real-time watts and logs daily, weekly, and monthly totals, so you're not spot-checking once, you're watching the actual pattern over weeks.

At $11.99, it's priced like the accessory it is, not a serious standalone energy monitor, and it reads one outlet at a time, so you're choosing which single device earns the permanent monitor versus which ones just get the one-time Kill A Watt check. For most households, that's the always-on suspect: a home office setup, an entertainment center, or, fittingly for this issue, a window AC unit or water heater on a schedule you actually want to verify is working.

It also works as a basic smart plug on its own. Schedule it to cut power to something overnight, or pair the schedule with your utility's off-peak window if a device doesn't have its own delay-start button. The product page has the full spec sheet, including the max load it can safely switch, worth checking before you put it on anything that draws serious current.

We haven't run this specific plug through months of daily use ourselves. The energy-monitoring feature and load rating above are SwitchBot's own published spec, and the smart-plug basics are the same mechanism as every other Wi-Fi plug in this category.

Do you know your own utility's peak hours off the top of your head, or did this send you digging for your last bill? Hit reply, we're curious how many of you are already on a TOU plan without realizing it.

See you tomorrow.

The Home Wire.

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