Do you have stats on this? I've developed coffee makers and other appliances. Yes, there's often a mode where the boiler keeps warm for some amount of time after the first cup is made. The first cup can take minutes to heat up, and the second is often much shorter. Then there's a certain amount of time where the preheat is left on, and eventually it's turned off if the coffee maker isn't used again. Different models/makes have different algorithms and modes, but this is a common pattern. There are energy conservation standards which also come in to play, so unless we're taking about a commercial machine, I don't think anything current will just keep the preheat on forever.
"Keurig brewers – unless turned off – continuously heat the water inside the heating tank even when the brewer is sitting idle. Some Keurigs such as K-Cafe and K-Elite feature an auto-off function that switches off the brewer two hours after its last brewing to save on energy."
I guess if your machine is trashing the planet with plastic waste anyway, why not also trash it on the energy consumption side? What a disaster.
I keep an electric kettle and Melitta pour-over on my desk at work. It is on when I turn it on, then it is off. The Keurig has always seemed like kind of a bad deal.
I guess you could make a case for this kind of thing in a breakroom or something where it's going to be in use all day, but then again, that's also the scenario where it would make the most sense to just be continuously brewing whole pots of coffee in a conventional drip machine.
Either way, a Keurig in a home, only brewing once or twice a day? The worst.
