Is it the Nest the single greatest invention in human history? Probably not. Is $250 a lot of money for a thermostat? Of course.

That being said, after a year of using the Nest, I’ve become an evangelist.

I’m going to break down my real costs, and while there are all kinds of variables to consider when making comparisons between what I have seen and what you might see, this should at least give you a decent idea of what your savings could look like.

For us, the plan was simple. Our energy bill from June 2011 – May 2012 was $2,010.That’s a whole lot of money, and we were looking for ways to cut cost. Thermostats control about 50% of any energy bill so that seemed like a good place to start. Less than an hour after picking up a Nest, our old thermostat was off the wall and the Nest was up and running. Installation is crazy easy.

So here we are, a year in, with at least anecdotally good results. Our energy bill for the first 12 months of Nest usage was $1,352. That represents an energy cost savings of $658 (32%).

I really think the Nest does 3 things better than even very good programmable thermostats.

• It’s very easy to program. If you can use a smart phone, you can program a Nest – without a manual.
• Auto-Away – I don’t know how it’s so good at knowing when you’re gone, but it’s impressive.
• Airwave – Coolest thing, it cuts off your A/C but keeps the fan running across the condensor to get every ounce of cold into your house.

All in all, the Nest saved us a lot of money, and I’d highly recommend it.

By the way, here’s a pretty chart showing our energy saving month to month:

I have the Gen 1 version so I have no idea if Gen 2 would have the same results. It should, but I don’t know.