Oy. The unit of heating/cooling temperature comparison is the degree-day, not the average temperature of the month.
For each time period, take the difference from your desired temperature. If you have an acceptable range, take the difference from the near edge of that range.
e.g. with a desired range 65-75, a 40 degree day counts as negative 25 and a 90 degree day counts as positive 15.
Keep track separately of positive and negative.
Now you have a record of how much you needed to cool or heat. Local newspapers -- remember those? -- will usually keep track for you on their weather page.
That's a suitable basis for comparison. Not monthly average temperature, not average high, not average low.
>Now you have a record of how much you needed to cool or heat. Local newspapers -- remember those? -- will usually keep track for you on their weather page
Yahoo! has a great free weather API with historical data, as does NOAA.
In Texas, companies give away Nests [0][1] to lure customers, thanks to the deregulated market. Competition is so healthy, they are even trying to capture 'green' customers who use less.
If I was to guess, I'd say they are most interested in the idea of smoothing demand. The more base load and the less peak load, the more profitable you can be.
If I were to guess, I'd say that buying electricity at 3 cents/kWh and selling it at 12 cents/kWh is profitable enough that you can afford to give away a thermostat to attract new customers. There's a $300 cancellation fee so they'll get their money back if you depart early.
Note: Our peak capacity is ~68,000 MW. There are some peaking-plants that may be brought online if we exceed that, or we'll begin having rolling-blackouts like last summer.
Thanks for pointing this out. Many people think we're a "yeehaw" state, but we have more wind farms than California to the tune of 2x more [1] thanks to oil money. I guess you can say cowboys like their texas tea, lower taxes, and greener pastures.
Californian cities are making it awfully difficult to resist the appeal of places like Austin.
The dysfunction in government and the general unfriendliness to the upwardly mobile is appalling.
California neither benefits from the good Puritan economic sense seen in New England states nor the thrift of good-governance states like Montana.
Yes, Montana ! :
For six years it has been one of the only states in America with a budget surplus: this year it is a record $433 million, proportionally equivalent to a federal surplus of $858 billion. Thus we’ve been able to cut taxes, invest in education and infrastructure and keep essential services intact. We recently got our first bond rating upgrade in 26 years.
And we’re not simply riding the Western energy boom. The recession has driven unemployment to 7.5 percent, and while we’ve had a great run with oil, coal and gas, royalties from these commodities account for only 9 percent of our budget surplus.
How do we accomplish what most states and the federal government cannot? I like to say we run government like a ranch. In ranching — my old job — you either pinch pennies or go belly-up. We do the same in government. Perhaps Washington can try it.
For one thing, we challenge every expense. If it isn’t absolutely necessary, we eliminate it. When the recession came we found $80 million in savings, which helped us avert a budget crisis. Little things added up: we renegotiated state contracts, cut our energy consumption by 20 percent, auctioned off state vehicles and canceled building projects and computer upgrades.
"A boom in revenues from sales taxes as well as taxes from oil and natural gas production have given Texas a budget surplus that the state comptroller has estimated at $8.8 billion."
And of course California is bleeding companies and jobs. No wonder its on the verge of bankruptcy:
"I tracked for 2011, that 254 companies of all sizes and shapes and kinds left the state for primarily other states,” said Vranich, the president of Spectrum Location Services in Irvine."
Some of it is just having a lot more wind, which sure helps when it comes to wind power. Texas's 50m wind-resources are somewhere around 20x California's [1], mostly because the usable generation area in Texas is across a huge area, while in California it's limited to some areas of the Sierra Nevada [2].
Yeah, growing up I had the impression that California was this place where everybody was more interested in renewable energy and saving the environment than most other places.
The reality is California doesn't really make an especially strong showing.
I think Texas is a great state. I live in Georgia. I travel to Texas a lot. I've visited Houston, Dallas, and Austin. Houston is a decent city once you get to know it and if you can embrace the cowboy-style. Dallas is fine; although I never really got the feel for it. Austin is awesome. I could visit Austin any time; if I wasn't happy here in Georgia I could easily live in Austin.
Houston is a decent city once you get to know it and if you can embrace the cowboy-style.
Now I'm wondering what I missed in Houston. I lived there for years, and graduated from high school there. But what do cowboys have to do with it? My experience of it was that it was just a modern American city like anywhere else, with a heavy focus on sprawling suburbs. I didn't feel there was a lot of uniquely "Texan" culture or anything. Life had little to do with cowboys; it revolved around living in suburban houses that cover literally hundreds of square miles (most of the city), and doing things like studying to get into good colleges and trying to get a decent job. Nobody I knew even spoke with a Texan accent, which was something more associated with West Texas or the Panhandle, places like San Angelo or Lubbock.
Now if you had said flying cockroaches, africanized ants, hurricane evacuations, and 6 months of the year where you can't reasonably go outside because it's >90 F and humid as hell, then yes, it's great if you can embrace that part of the lifestyle. ;-) I do like visiting nowadays, but only in December.
The OP must've come during Rodeo season - which is about the only time the city generally has a "cowboy" feel to it. =) Unless, of course, they were located some many miles to the northwest of the city, out in Waller county or something.
BTW, you left out flooding every other week or two, when we're not in a drought (and once a month when we are!). The running joke around here is that no one feels the heat of the summer for more than a few seconds, as that's how long it takes them to get from their house/office to their car.
To the original point of the post, we haven't been able to find any value in getting a Nest, outside of having a "fun toy." Considering that we are able to regularly negotiate 0.08-0.10/kWh rates for 100% renewable, our highest electricity bill out of the year tends to be in Aug/Sept at about $58 on average. That is for a 1400 sqft. 1940's bungalow that only has a radiant barrier in its efficiency profile, along with large oaks that cover the canopy of the house. Our elec management is a simple process: set the thermostat to 80 when we leave, and back to 77 when we return. It's three clicks of a button that we've ingrained into our daily routine.
The real big bill around here, which I'm sure other states can appreciate, is the water bill. Since the drought and the implementation of drainage fees, our water bill has shot up over 10x in the past three years. Not joking at all - we went from an average of $6/month to and average of $60/month in just three years, with our consumption remaining static. If only water consumption were able to be regulated more effectively, but in this environment, daily showers are a must =)
I wouldn't say it has great museums, having moved from Chicago to Houston as a kid. I found most of the museums... not as good in comparison. But Chicago has particularly good museums, so this might be unfair.
It does, however, have very good art museums specifically. And even more specifically, it has good art museums that are well-endowed enough to be cheap to visit. The Museum of Fine Arts Houston has one of the lowest entry fees of major metropolitan art museums, and the Menil Collection is completely free. Definitely a high-culture perk of the city.
Also, if you are willing to drive ~20-50 miles to visit something (and you had better be, if you are in Houston) there is NASA's Johnson Space Center, where you can see lots of rockets and rocket facilities; and Brazos Bend, where you can see lots of alligators.
I wasn't impressed with Chicago's Field Museum compared to HMNS, but I've only been there once, and IIRC there was renovation going on, so maybe I missed the good stuff. I'll give it another try next time I go to Chicago. Glad to hear someone is enjoying the MFA and Menil. The Menil was mostly the result of the Schlumbergers IIRC.
I lived in Clear Lake when I was young, and I was fortunate enough to get to hang out at JSC, and get really good access to the place. My Little League coach was an Astronaut. I can barely stand to go there anymore. It kills me.
Alligators? Yeah, and mosquitoes. I've seen enough of both.
On the science museum, part of my view, I think, is that HMNS is trying to do what two different Chicago museums are covering: the Field Museum (classic archaeology / natural science) and the Museum of Science and Industry (modern science, and technology of the industrial revolution to present).
The Chicago Field Museum is a classic "natural science" museum: a very large, multistory lobby greets you, with a monumental dinosaur reconstruction. The building is also impressive, from some century-ago world's fair. The rest of the exhibits, on the other hand, range from good to being quite obviously 100 years old with no love given in the preceding century (sometimes this is nice and quaint, sometimes annoying). It feels more impressive to me than HMNS, but HMNS might have better exhibits. The latter certainly has a nice gem collection.
But if you want something more sciencey, the Museum of Science and Industry is really nice. There's an entire simulation of a coal mine you can go down into, exhibits on the history of trains, on urban history, and on the history of agriculture, and even a captured German U-505 submarine. It was definitely my favorite museum as a kid, and I didn't find much like it in Houston.
These companies also charge a higher rate and lock you in to a long term contract. So they are just financing it for you. It probably works out to a crazy interest rate but people love it.
If we're going the route of reducing usage, I'd rather the gov't give a tax credit for reducing energy usage each year. The consumer should decide how that energy is reduced. If they want to use a Nest, great. If they want to manually adjust, fine.
Give the consumer incentive to reduce energy usage and then allow them to decide how that's done. If gov't forces a specific thermostat, chances are the process will be corrupt and inefficient.
In a oil burning boiler property with 8 baseboard zones and 8 Nest units, it saved me a thousand dollars a month all winter. Paid for itself the first winter.
Previous thermostats were programmable "eco" models that I kept programmed and used away/vacation modes on.
Savings was from being able to see on/off cycles for all 8 zones to better balance them, so boiler was on less overall.
I've recommended them to others and use one in a loft as well. Every installation is saving at least 10%.
He's confusing kilowatts with kilowatt hours? They mean very different things. kW is a rate (kilojoules/sec) of usage (power). kWh a stackable amount (in the sense that you can stack money) of energy and is what the electric company charges you for. A basic mistake like this makes me question the validity of the results.
I'm in the market for 3 new thermostats and was hoping this article would help me with my decision. Presently, I'm leaning toward an Ecobees (https://www.ecobee.com/) thermostat which has a lot more features than the Nest and even has an API. It seems to be the Android of the thermostat world where Nest is the iPhone. Features vs polish.
Nope, it's not worth it. And this data does not prove it is.
I need to know everything about the conditions prior to installing a Nest. In particular, I need to know about the thermostat and, if programmable, how it was programmed. I also need to know about living patterns. Did anything change? Was the programmed temperature higher in the summer and lower in the winter with Nest or was it set to about the same conditions?
In terms of energy efficiency. How is the house insulated? Can you add insulation to the walls or attic? Are the windows double-insulated? Do you use a whole house fan in the summer to cool the house at night? Do you have a multiple zone system so you don't have to heat or cool the entire house when you spend all day in, let's say, an office or the kitchen? Is it a two story home? Do you push hot air down in the winter in order to equalize the temperature? Do you have attic ventilators?
I see Nest as more of a neat gizmo with lots of marketing behind it than a real solution to a real problem. To be sure, the real solution requires a lot more work than bolting a piece of slick looking electronics to a wall. The payoff from a real solution would almost certainly be far greater and it doesn't have to cost a lot of money. For example, I use a $200 fan to cool my home at night (taking advantage of my local conditions). We have probably used the air conditioner a grand total of four weeks in the last three years. The savings in three years are already in the thousands and the investment was $200.
Like most engineers/geeks/hackers, you've completely missed the point of the Nest. The point is: people like to adjust their thermostat. They're too hot? They want to cool it down. Too cold? Turn it up. The Nest allows one to perform those actions while retaining some level of efficiency, and additionally attempts remaining possible optimizations (e.g. turning the A/C down while you're not at home).
The Nest is not about ideal efficiency -- it's about a system that works with the way people already behave.
If you're comparing against an ideal savings regime, I imagine it's not worth it. However, in my case, I was always putting off figuring out how to program my thermostats, deciding it was too much trouble to adjust them, etc. Against that, I expect the Nest to pay off fairly quickly.
But given that the average contract developer is charging themselves out at $100/hour investing the time to "program a thermostat" will rarely result in a ROI.
This has got to be one of the most impressive uses of "My time is worth too much to do X" I've ever seen.
It took me like 10 minutes to program my schedule into my cheap honeywell programmable thermostat. A leisurely 10 minutes. I can't speak to my ROI on the endeavor, but since the thermostat was ~$25 I can only assume I'm rocketing toward breaking even.
my hat is off to you if you are able to sell all the 16 hours that you're awake every day to someone for 100$ each without dropping in productivity and maintaining mental well beeing.
It will. I bought a house 3 months ago and it had a terrible thermostat that was difficult to program and even programmed it would reset itself occasionally. We bought and installed a Nest and it programs itself by learning your patterns.
I don't know if it's saving us money because I have no baseline to compare it to (other than the previous year's electrical usage comparison on our electric bill), but the device is a breeze to use. The app is nice as well when you are laying in bed and it's too hot or cold in the house - just grab your phone and change the temperature.
Meanwhile, my father had mastered the old VCR-style programmable thermostats, but he doesn't really 'get' the Nest I gave him. Too high-tech and automatic for him. But, Mom likes changing the temperature from her iPad.
I see a vision of all our futures. Cranky old tech guy and hot-flashing old woman spend retirement in hacking war to set the indoor temperature with their phones/tablets/whatever we're using in a decade or two.
For me, it made a larger difference in my awareness of how much energy I actually use. Before nest I simply programmed my thermostat once and never touched it again because of the pain. Now I consciously adjust the temperature throughout the day from my desktop or phone. Just being able to walk out the door and turn the temp down from my phone if I'm suddenly not going to be home for a while is savings enough for me. I'm sure there are other thermostats that do the same thing but nest has done their advertising right and their interface/product design is top notch.
I think it would be worth looking at this using "degree days". (Degree day stats from Wunderground, I eyeballed his KW since no firm numbers are provided).
* August 2011 vs. August 2012: 809 cooling degree days vs. 594 (1.36x). 2100 KW vs. 1500 (1.4x)
* January 2012 vs. January 2013: 544 heating degree days vs. 595 (0.91). 3000 KW vs. 2000 (1.5x)
So accounting for the weather with "degree days", with A/C it looks like there was no savings, but with heat it made a massive difference.
There is also the "poor man's nest" - the Filtrete 3M 50 which is $89 on Ebay and fully wifi supported with a well-documented API and fantastic Android app:
I'm not sure looking at the pure money saving in terms of lower energy is the way to go, since a lot of the benefits are more intangible than that. The ability to detect when you're away, automatic scheduling and easy control from a smartphone are pretty big benefits for me but they'd be hard to quantify in terms of being "worth it".
As others have pointed out, you can achieve a lot of that with other (cheaper) products. But to be honest, I think Nest's main strength is making the features easy and fun to use rather than having totally revolutionary new features. But that's the Android and Iphone claim to fame in the smartphone world, and they did OK ;)
This needs to be correlated to the weather/temperature pattern of the two years since the nest is on your HVAC. Much of the US has had a milder summer and winter than the previous year; it may be the same for you.
I live alone in a house, in Phoenix. I use pynest to set my Nest to "Away" when my iPhone leaves the network (I just ping it constantly from a script).
My power bill is a lot less than it was pre-Nest, and it requires no effort. Accessing the Nest when I'm about to head home is a nice benefit, too, to get the house cool before my iPhone is detected again.
(I have a sporadic schedule so the auto-away feature wouldn't work for me).
I had a Nest early since I preordered it. Unfortunately it just died so I'm not the happiest person.
But, over the 1.5 years I had it I saved about 3% from previous years with a dumb thermostat. This doesn't recoup the cost at all.
One reason the savings was so low was that the firmware on the Nest was very inadequate during the 1st year. It didn't even do automatic heating/cooling on a schedule. All that was resolved last year.
The other reason is that the Home/Away detection is worthless for me (and I suspect many folks) because the thermostat location isn't in the traffic pattern of the house. I've pleaded with them to do a remote sensor but so far they don't care. Most of the new modern wireless system have the ability to add remote sensors so they're being left behind quickly.
Even so I'm not disappointed in the Nest. It's cool and I am very pleased to have wireless access via my smartphone to the temperature settings.
But they need to do a lot a work to get back to the level of companies like Honeywell and their distributed system.
The failure stories I have heard convince me these are not fail-safe devices. If the thing shuts down in the winter and doesn't restart correctly, and you are away, you could come back to frozen/burst pipes. (Probably hasn't happened yet, but the failures have happened, so it's likely just a matter of time.)
So I would only use one of these paired with a conventional thermostat serving as a safety net, in case the Nest fails. But then I resent having to compensate for a manufacturer that cannot be bothered to build the failsafe into their own product in the first place.
I live in an area where you rarely need air conditioning. Many homes around me do not even have them. However we do need heating from about November to about April, but it rarely does get below freezing. With that said my power bill is about 50/month for gas and electricity. I really didn't need a Nest, but it is certainly a fun tech toy to have. Being able to remotely turn on my heat or AC remotely is pretty nice when you want you're on your way home. So even if I don't make back the $249 that I spent, I still feel that it is worth the money.
I believe the "auto away" detection feature on our Nest has made the biggest impact on our energy bill. Nowhere close to what the OP is saving, but I'd bet it's in the $50/year range.
Feels like a tipping point for Nest. Someone like this could be the next Apple.
I feel strongly a few of these Internet enabled devices will pave the way for a new industry. Imagine Nest being purchased by every household (like the iPod) and then moving on to other products.
At some point it feels like they could charge a subscription. Would you take a free device and pay them 10$ of your 30$/month savings?
It is very unlikely that this is accurate, or there are substantial externals that are not being accounted for (e.g. stopping using a desktop as much as a tablet gets heavy usage) -- the difference between 2012-01-01 and 2013-01-01 is just way beyond what even the biggest Nest hyper claims.
Outside of savings that grossly exceed even the best expectations, when questioned whether they used a programmable thermostat already (the absolute bog standard $20 variety automatically dropping the temperature in a manner that is close to optimal for about 95% of people), the author gave a very wishy-washy answer that didn't actually answer the question.
I've been a Nest user since nearly Day 1, and about 19 months now overall. At this point I've probably recouped about 80% of the price of the thermostat, with my electric bill reduced by about $10-11/month ($55-65/mo to $45-55/mo) for a 725 sqft luxury apartment.
I should probably write a blog post with all the details, but here's my take:
* I have a south-facing apartment with about 110-square feet of window glass. It heats up like a sonofa in the morning. I was able to counter this by setting a warmer limit for cooling in the summer. The blinds were always correctly set every evening to minimize summer cooling and winter heating.
* The leaf stuck out at me. I always wondered "why can't I get the leaf with my setting -- what do I have to adjust it to to get the leaf to appear?" This resulted in behavioral changes such as wearing different clothes, and taking better advantage of the windows to make getting the leaf to appear achievable.
* Once I hit the leaf, I then looked into other ways to maintain comfort, particularly in the summer. I've since invested in a fan to eliminate the envelope of heat that surrounds my body. Running the fan 20 hours a day is equivalent to running the A/C for 20-25 minutes, which is a big savings if I can eliminate 2.5 to 3 hours of A/C usage a day (at 18.5 cents/kWh).
With the addition of the fan, and finally finding some LED light bulbs with the right lens type and color temp (to replace some halogens in the track lighting), my electric bill was $42 for July, despite the ridiculous northeast heat wave. Despite constant 90+ degree temperatures and high humidity, I was able to get by with about 1 hour and 15 minutes of A/C a day, and didn't feel bad about it.
I'm not sure I agree. If the Nest helps to change your habits then I would consider it a net win. It doesn't really matter how you saved the money, just that the Nest is paying for itself. Sort of like paying Weight Watchers to help you stick to your diet. :)
This is what I was trying to get across. The Nest isn't magic. Instead it provided information I could use to adjust my habits, and provide the data to show that my changes were resulting in a net benefit.
Of course, you don't need a Nest to learn to change your habits. Just stop using the HVAC, and you'll come up with alternatives. In my case, a mixture of fan usage and blinds/window usage.
If the nest is what makes it fun and simple enough to change the habits, it's entirely reasonable to say the nest caused them. Maybe most of the value of the nest comes from behavior modification rather than more precise temperature control. But even so, that's still value.
Exactly. It's like how the LCD with the real-time and historical fuel economy info in the Prius has been teaching people to drive more efficiently via the instant feedback you might not get in most other vehicles.
It's easy to say you could achieve the same thing without it, but facts show most people don't.
Many, many vehicles have real-time fuel-usage meters. Most people completely ignore them. The people who care about fuel-usage -- the sort of person who buys a Prius -- of course pay attention to it because it justifies the reason to buy the car.
Yet I suspect that very few of the people who bought the Nest actually care about energy usage, or reducing it. It is a lifestyle product and is a talking point, and while there are some who really desire it for that, many more set it to a static temperature and forget it. I hugely doubt that the total set of Nest users have seen any measurable decline in usage.
Isn't there a huge difference between the meter that the Prius has and the typical "real time" fuel meter. In particular, it is difficult to see how instant readings contribute to long term averages.
Not as many vehicles had those when the Prius first came out, and even now few make MPG as front-and-center with graphs and such. Implementation matters.
I have a south-facing apartment with about 110-square feet of window glass. It heats up like a sonofa in the morning.
You should consider solar screens. They cost about the same as regular window screens and are remarkably effective at keeping the heat out because they are on the outside, so the heat never enters the living space. Take them down in the fall when you start to want the heat.
At this point, it'd be diminishing returns. If it cut another $3-4/mo off the electric bill, time to recoup would likely be in excess of a decade. Next, it would ruin the gorgeous view I have (I very deliberately chose having a wall of glass). Additionally, it's an apartment building so I can't do any exterior modifications such as that. Last, I'm on the 4th floor, where installing 7 foot x 3.5 foot screens might be a bit dangerous.
Compared to buying a fan and a Nest, way too much effort.
TL;DR: Too much effort and sacrifice for negligible return.
Just so no one else gets the wrong impression - solar screens don't ruin the view, unless your nose is right up against them, they look like window tinting. Also it isn't just about saving money but also increasing comfort for the same amount of money.
Heck, I didn't have a programmable thermostat for three years, in Atlanta, and would be surprised to see anywhere near these savings. I had a thermostat with a manual lever, which was mechanically coupled to a mercury-glass switch that controlled the A/C (this was a new apartment building built in 1999, strangely enough, not some ancient relic). I turned the thermostat way up (i.e. reduced the intensity of the A/C) when I would leave, and turned it back down when I got home. This by itself was enough to reduce almost to zero the operation of the A/C when I wasn't home, which was a pretty good approximation of the desired outcome.
"the difference between 2012-01-01 and 2013-01-01 is just way beyond what even the biggest Nest hyper claims"
Doesn't the temperature chart explain most of the savings? A colder winter and hotter summer for the first year (pre-Nest). The simple total of net degrees by month disguises the fact that the second year is much milder. What you want to look at is KWH from months (days if possible) with nearly identical avg temperatures, come up with composite "savings" for different month types and project that on a year.
Below are the charts for each period. My attention isn't here but if someone with some statistical know-how wants to give even a casual analysis it would be interesting.
I agree ... And the thing I noticed is that during the cold snap (which wasn't nearly as long but was just as cold), they hardly used any power compared to the previous year. Perhaps they wer on vacation? I think "occupied hours" would be pretty important for these measurements. And if you multiplied occupied hours times the inside-outside temperature differential, you'd (maybe) start to see some patterns.
It's a convention of building physics to convert all energy useage to kW (sometimes BTU in the US) regardless of whether its gas, electric, oil, biomass etc. For example, Passivhaus calcs are done this way.
For each time period, take the difference from your desired temperature. If you have an acceptable range, take the difference from the near edge of that range.
e.g. with a desired range 65-75, a 40 degree day counts as negative 25 and a 90 degree day counts as positive 15.
Keep track separately of positive and negative.
Now you have a record of how much you needed to cool or heat. Local newspapers -- remember those? -- will usually keep track for you on their weather page.
That's a suitable basis for comparison. Not monthly average temperature, not average high, not average low.