I haven't directly noticed any savings (although I haven't payed much attention,) but the design, remote access, and general pleasantness of it are well worth it.
They have clearly paid a lot of attention to even the smallest details and if you like that kind of thing, a Nest Thermostat will make you very, very happy.
I bought one of these at the beginning of the summer and I definitely noticed a fairly significant savings. In my case I updated from a really old, couldn't-be-programmed, thermostat right to one of these which almost certainly skews the results since any kind of programmable thermostat would have shown a savings.
I live in NJ and work in NYC so during the week I'm only home for a few hours, besides sleeping, and it learned my schedule on its own. When I get home it's just kicked in and started bringing the temperature down and it goes off shortly after I leave.
The only issue I had was during the first setup it mixed up the heater and air conditioning because of my settings. But I just restored and went back through and changed what I selected and all was well.
I bought two of these, and a guy I work with bought one. My co-worker has measured pretty significant savings in his electric bill. I have not, but it's because I just bought this house and installed the Nests pretty soon afterward so I have nothing to compare.
I'm wondering if they provide any meaningful savings vs a cheap programmable thermostat. Putting your HVAC on timers so it runs less will obviously save energy, but can Nest actually do much better than a unit from Home Depot?
When you're running the AC, it actually learns how long it can continue to cool by just running the fan due the the lingering coolness of the coils after the compressor has been running. This causes the AC compressor to run less while you're still able to be kept cool, at significant cost savings.
Your standard thermostats currently don't do this.
Well... the really cheap ones are just timers/thermometers. The amount of control you have over it is related to how much you can program it. I used to have one that was very simple: I could set 2 times/temps for the week and 2 for the weekend. It was easy to program but didn't have much smarts. SO on days that I worked form home, it still let it get hotter/colder for my pre-programmed "away" time frame. So I was constantly tweaking it when I was not really away. My new house had some fancier ones that gave me more times/temps to program and I think I could adjust them per day (not just "week" and "weekend") but it was actually overly complicated to program. And some of the fancier ones still cost $150-175 at HD. So at $250, the Nest is not that much more expensive than some of the fancier ones at HD. But you get some much more "smarts" with it. And you get all the cool extra stuff like remote access, monthly usage reports, habit learning, etc.
> I'm wondering if they provide any meaningful savings vs a cheap programmable thermostat.
In my experience, yes. I left town for two weeks and forgot to turn on away mode. If I'd had a cheap one, I'd have paid for two weeks of A/C keeping my house at 72. Instead, I was able to remotely tell it to let the house get up to 85 before kicking in.
Auto-away does the same thing on a smaller scale on a near-daily basis for me, as well. We've got a pretty unsettled schedule, so it's a wonderful feature.
I bought one 3 months ago (damn!) and am very happy with it. I can't say for sure I saved X dollars but between airwave, auto-away and it's easy scheduling (compared to my old, confusing, impossible to understand thermostat) I can't imagine it hasn't saved me at least some money.
But on top of that it looks good in my high traffic hallway. Being in the hallway to my bathroom it acts as a nice night-light (it turns on when I step out of my bedroom to goto the bathroom and visa-versa) and overall has been a joy to work with.
