This is the second in an occasional series about my Nest learning thermostat. See Life with a Nest learning thermostat: week one for the first installment.
Last night, my wife went out for dinner with friends. When she came home, she asked me what I'd been up to:
"Oh, I've just been comparing our gas bills for January 2014 and this year, and then figuring out the average daily temperatures for the month to see if we've been saving money."
The response was an eye roll.
Lower gas bill
When I told her that our gas bill was down $46 (about a 22% reduction), she seemed a little less annoyed. Coincidentally, my evening of geekery coincided with the release of a press release and white paper from Nest suggesting, on average, Nest owners really do save money—and this appears to be the case even when they replace an existing programmable (and programmed!) thermostat. Here's the very top-level summary:
Two independent studies and one internal study later, here’s what we know: On average the Nest Learning Thermostat saved US customers about 10-12% on their heating bills and about 15% on their cooling bills. We’ve estimated average savings of $131 to $145 a year, which means the Nest Thermostat paid for itself in under two years.
Now results varied, of course, from household to household, with some saving a lot more, and some saving none at all. (Apparently single-person households and older owners were least likely to save.)
A focus on behavior change
As I mentioned in my first post about the Nest thermostat, I remain convinced that far more than the fancy auto-away and time-to-temperature settings, one of the biggest advantages of the Nest is that both the thermostat itself, and the overall user experience, is designed to make you think about your energy use—and specifically your heating and cooling—more than you otherwise would.
From the access to energy history to the little "leafs" (yes, the plural of a nest leaf is leafs, apparently) you receive when you turn the heat down, the value of the device is as much about leveraging behavioral psychology as it is fine tuning how your HVAC's actual operates. For example, using the energy history function, I've been able to see first hand the difference in furnace runtimes if I set the nighttime setback to 63 instead of 65.
Nest are by no means the only folks thinking about this stuff. As I wrote over at MNN recently, from product designers to the US military, there is a huge amount of research (and investment!) going into how behavioral psychology can promote energy efficiency and conservation.
The Nest blog is just one example of how the overall user experience promotes energy literacy. Topics range well beyond HVAC itself, looking at weatherization, overall household energy use, and even the differences in how men and women perceive hot and cold. (Yes, women really are biologically predisposed to feel the cold in their extremities—apparently!)
Add this energy literacy advice to the fact that Nest sells blankets alongside its thermostats, and you start to get a picture of how they are positioning themselves as an energy (and comfort and convenience) focused lifestyle brand, more than a thermostat maker. Smartness is nice, but I suspect Nest will prove to be an ally in promoting the cause of the dumb home too.
Let's not jump to conclusions
As I noted in my first post, I cannot isolate any savings between this year and last year specifically to the installation of the Nest. Since last winter, we''ve added floor insulation. We've caulked some baseboards. We've weatherized some doors. And our schedules have changed too. (I suspect we would not have changed our thermostat settings with the old set up though.)
Oh, and if I did my calculations correctly, the average daily temperatures were also about 3 degrees colder here in January 2014. (I will say though—it would be nice if Nest's energy history helped me to see average daily temperatures, rather than having to figure them out myself.) Our price for gas was ever so slightly higher though too.
Still, it's always nice to see your energy bills go down. And it's kind of fun to spend an evening trying to figure out why.