NEW YORK — Electric bills have long been take-it-or-leave-it affairs: Pay one rate for all the power you used the month before, no matter when you used it.
But some electric companies want to shake up that rigid business model. They are increasingly offering plans that sound like come-ons from mobile phone companies: Free nights, free weekends, and pre-paid plans.
‘‘We are seeing a transformation in the way people buy and use electricity in the US,’’ says Steven Murray, president of Direct Energy’s residential energy programs.
The more customized plans are made easier by the growing use of digital meters that wirelessly link electric companies and customers, allowing both to track usage in real time.
Digital meters have not only spurred competition, they have also enabled traditional utilities to reduce their costs by encouraging customers to use electricity during off-peak hours, when it is cheaper.
Forty-two percent of US electric customers have digital meters, up from less than 5 percent in 2008. In 2015, more than 50 percent will have them, according to Navigant Consulting.
This new breed of electric plans comes with risks.
Customers can end up paying a lot more for power than they expected. Some plans offer low introductory rates that can quickly skyrocket.
Others have high early-termination fees. Some fixed-rate plans are a great deal if power prices rise, but they may seem awfully expensive if prices fall.
If customers are careful, though, they can pay less.
Dorothea Miller of Sinking Spring, Pa., signed up for a Direct Energy plan that gives her one day of free power every week.
She picked Saturday, and now saves as much of her housework as she can until then.
She stops short, she says, of letting mountains of dirty laundry or dishes accumulate in anticipation of Saturday’s free power.
‘‘We pretty much run things the way we did before the plan, but now we set our dishwasher to go on after midnight [Friday] and do most of our laundry on Saturday,’’ she says.
TXU Energy offers a similar plan to Texas customers that offers free power every night from 10 p.m. until 6 a.m., or free power Saturdays and Sundays, in exchange for a higher rate during other times.
Customized plans are most prevalent in the 13 states and Washington, D.C., where regulators have allowed companies to compete to sell electricity.