At 3:15 on a Friday afternoon, Tessa was at the top of the basement stairs with a full laundry basket when I called from my desk in the office, "Can that wait until seven?" She looked at me for a long second and said, "You read the bill again."
I had. Our Consumers Energy bill for July came to $146 for electricity. June had been $109, and a normal month outside summer runs us about $88. Some of that is just Michigan in July and a 2011 air conditioner doing its job. But the bill also breaks our usage down by time of day, and that part bothered me.
What the bill was telling us
We're on Consumers' summer peak pricing, which on our rate at the time means electricity costs more on weekdays from 2 to 7 p.m., June through September. Weekends and every other hour count as off-peak. When I added up the lines, about a quarter of our kilowatt-hours had landed in those five weekday hours.
It wasn't hard to see why. The AC works hardest in the late afternoon. Friday is Tessa's day off and my work-from-home day, so Friday afternoon had become laundry day, and our dryer is electric. Dinner happens on an electric range around 6, and the dishwasher used to start right after. We'd built our whole week around the five most expensive hours in it.
The 2-to-7 rule
We didn't want to live in a hot house to save a few dollars, so we kept it simple:
- No laundry and no dishwasher between 2 and 7 on weekdays. Weekends are fair game.
- On Fridays, when I'm home, I cool the house to 72 by 1:30, then set the thermostat to 76 until 7.
- Monday through Thursday nobody's home in the afternoon, so the thermostat sits at 76 all day and nobody touches it until evening.
- On hot weekdays, dinner goes on the grill, or into the slow cooker in the morning, when we remember.
Our thermostat is the original kind you adjust with a thumbnail, so the Friday pre-cool runs on a phone alarm at 12:45 that just says COOL THE HOUSE. A thermostat that can do this by itself is now on my list for the fall.
The laundry part needed some negotiating. Tessa made it very clear she would not be folding towels at ten o'clock on a Tuesday night, which is fair. Laundry moved to Friday mornings and Saturdays, and the dishwasher runs right before bed. That covers most of it without anybody waiting up for the dryer buzzer. The part I didn't expect to like is that Saturday laundry gives the weekend a rhythm: everything's folded by noon, and Friday afternoons are quiet now.
Upstairs, where the sloped ceilings hold heat like an oven, we added a box fan in a dormer window at night instead of turning the thermostat down. It does more for sleep than another degree of air conditioning, and it runs while the cheap hours are on.
The dehumidifier I left alone. It runs about six hours a day in summer, around $17 a month, and a basement that smells like a basement again would cost us more in other ways.
What August looked like
The next bill showed up yesterday: $131. That's $15 less than July, with most of the month under the new rule. Our share of kilowatt-hours in the peak window dropped from about a quarter to about an eighth.
I want to be careful with that $15, though. The middle of July was the hottest stretch of the summer and the last week was milder, so some of the drop is weather. The price gap between peak and off-peak hours on our rate isn't enormous per kilowatt-hour, either. Moving the laundry and dishes is worth a few dollars a month, not a fortune. The air conditioner is still the big number, and the only real lever there is how warm we're willing to let the house get, which in our house is a two-person vote that I usually lose.
At work we'd call this shifting demand off the peak, the same way you'd move a shipment off a slammed Monday dock. At home it mostly means the dryer runs on Saturday and I set an alarm on Fridays.
Moose came up with his own version of the rule without reading any bills. From about 2 to 7 on hot days, he lies flat on the basement floor next to the dehumidifier, on the coolest square of concrete in the house, and doesn't move for anyone.
