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Power

Smart Thermostats Inadvertently Strain Electric Power Grids (cornell.edu) 159

According to a new study from Cornell researchers, smart thermostats are initiating peak demand throughout the network at a bad time of day. From a report: "Many homes have their smart thermostats turn down temperatures at night in the winter," said Max Zhang, a professor in Cornell's Sibley School of Mechanical and Aerospace Engineering and the Kathy Dwyer Marble and Curt Marble Faculty Director at the Cornell Atkinson Center for Sustainability. "The temperature can be programmed to ramp up before you wake up -- and you'll have a warm house. That's the smart thing to do. But if everyone keeps their default setting, let's say 6 a.m., the electric grid suffers synchronized demand spikes and that's not smart for the system. That's the challenge." "As we electrify the heating sector to decarbonize the grid," he said, "this so-called load synchronization will become a problem in the near future."

In 2021, about 40% of U.S. homes had smart thermostats, as utilities encourage adoption, according to the paper. Lee and Zhang examined wintertime smart thermostat data for over 2,200 homes in New York state, noted for its cold winter climate and a mix of urban, suburban and rural communities. Homeowners purchasing a smart thermostat can opt to share their data anonymously with electric utilities for research purposes. Lee and Zhang investigated "setpoint behavior" and learned that most homeowners use the smart thermostat's factory-default settings. Evidence showed that residents remain confused about how to operate their thermostats and are often unable to program it, the authors said. In fact, their data indicates homeowners achieved energy savings of only 5% to 8%, far less than the devices' potential of 25% to 30%, Lee said.

If hundreds of homes have their smart thermostat set to turn on at 6 a.m., the electric grids see a peak at 6:05 a.m., which is about an hour before daylight during New York state winters. While the setpoint schedules are designed to achieve the energy-saving benefit, the peak demands are concentrated primarily when renewable energy is unavailable -- aggravating the peak demand by nearly 50%, according to the paper. "The smart thermostat data shows both an increase in frequency of high daily peak heating demand," Lee said, "as well as an increase in the magnitude of the overall peak demand."

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Smart Thermostats Inadvertently Strain Electric Power Grids

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  • by Powercntrl ( 458442 ) on Thursday July 14, 2022 @06:32PM (#62703672) Homepage

    Massive simultaneous demand is a problem utility companies are going to have to deal with one way or another. Imagine every car you see on the highway in rush hour traffic, arriving at home and plugging in. Today's grid would shit itself.

    • People take different amounts of time to arrive at home, and will produce a steep but still sloping curve. But all the thermostats that are set to come on at 6 am come on at... yeah, you know

      • by Octorian ( 14086 )

        Except people don't start charging their cars the moment they get home. They start charging at a pre-determined time during the night, often whenever the power company lowers their rates (if time-of-use metering is available). So really, without some policy and technical changes to randomize daily charging times, you're going to run into the exact same problem.

        • We have the technology to solve this though by letting the power company control the time at which the cheap electricity starts using a remote-controlled meter. This would let them stagger the 8-hour period of cheap power across their region and do more effective load balancing. After all, if charging your EV takes 4-hours you don't really care which 4-hours it is within some reasonable limits - say between 10pm and 6 am and you can always provide a "charge regardless" switch for the nights where that's not
          • by bingoUV ( 1066850 ) on Thursday July 14, 2022 @10:38PM (#62704162)

            Ok, so the electric company failed to allocate any time slot for me, and I can't go to my office the next day. Their terms of service already include this, and if I complain they say sorry. I lose my job, the company loses nothing. A huge majority of the country, and much of the world does not have a choice in electric company.

            Have you learnt nothing from handing over your lives to corporates over the last half a century? Airlines overbook, then say fuck you. Internet service providers over promise, and then ban you for "unfair usage". Companies selling food to you make it nearly impossible to find out what is in your food, and pwn the regulators to boot.

            • If you drive it entirely off the price then it should be fine. I can set my car to start charging at 3:12am or any time the price drops below 8c/kWh - that'd pretty give me control while also giving the utility some measure of control. Hypothetically the utility could also stagger price changes over their customer base - My power price might be lowest from 11:10pm to 6:10am and yours might be 11:20 to 6:20. that'd allow them to do more of a smooth ramp. I don't see a viable path to really greening the pow
              • Yes, the company controlling the price at various times, and communicating with the car / charger is more reasonable*. While the company controlling the time at which the car charges is a recipe for disaster in a corporatocracy like the US, even the "market" of electricity needs multiple providers otherwise the market is only for blind worshippers of poorly understood Adam Smith, not reality.

                * But even here there may be traps. The company may notice that in power deficient nights, people force charge at 3

                • I don't think there's any great value to the power company in trying to "trick" people. Their goal is to pair supply and demand and they don't really want to create bumpy demand by changing the price too often. Plus if they play those games then people will get smart chargers that adjust by the second.

                  I can see a role for regulation in protecting residential customers from the extremes - so we don't see a repeat of the texas situation with people charged thousands of dollars for one days power. Perhaps t
        • Texas power company can't even handle the winter and this summer. Then throw a bunch of EV's charging during the night and then are really screwed. Back to main point: I'll keep my "dumb" thermostat and my heating/ac guy recommends leaving a static setting to maintain a constant temperature instead see sawing.
          • by necro81 ( 917438 )

            I'll keep my "dumb" thermostat and my heating/ac guy recommends leaving a static setting to maintain a constant temperature instead see sawing

            Your heating/ac guy's recommendation is costing you money. Allowing your interior temperature to fluctuate, particularly when you are not at home or are in bed, uses less energy [google.com] and therefore saves you money.

            There is a middle ground between a "smart" thermostat and your "dumb" one. Programmable thermostats have existed for decades, and aren't connected to the i

      • People take different amounts of time to arrive at home

        Maybe so, but all of them are on the road at the same damn time that I am.

      • Yup, it's the electrical equivalent of a water hammer.

        Which is how China will actually defeat the US in a future cyberwar, program every smart toilet in the country to flush at exactly the same time. Ba-woooosh!

    • I had a Chevy Volt briefly, I got on a 'time of use' power plan where power was cheap from midnight to 6am. The Volt was configurable to start charging at a certain time, midnight in my case. You plug it in but it doesn't start charging until later when power is cheap. This helps the power company by shifting loads to different times and makes it easier to manage the grid. But everyone kicking on charging at midnight will be a whole new problem.

      • This type of thing is why smart grids are actually really neat and important. If every electric car can do that to keep demand even that will increase capacity. As long as people's cars are charged by the morning they won't care otherwise.

        • by bhcompy ( 1877290 ) on Thursday July 14, 2022 @07:20PM (#62703798)
          The problem is when they're not charged because the smart grid isn't expecting you to head to work 2 hours early today
          • Part of the smart grid though is you tell your car "I need to be charged by whatever AM and the car and the grid can sort that out. People who need to leave at 6 get charged earlier because people who leave at 8 can eat those 2 extra hours of grid capacity.

            Will it work that great in practice? Probably not at first but that's the idea.

            • by Mal-2 ( 675116 )

              I think the implication is that you normally leave at 6 am, but you got a call that says they need you two hours earlier than that, and you can't go because your car hasn't even started charging yet. In that case, a charging plan should be to top up enough to get back to the office, regardless of the cost of power, and then wait to fill up the rest of the way.

              • by Entrope ( 68843 )

                A home charger for an EV won't be a supercharger -- unless you have a really low-end EV, two hours will not fill much of the battery. So the hypothetical situation should only really affect people who need to leave two hours early and who have a long commute relative to their EV range.

                • Not entirely true; my car can charge at a maximum of 48 miles range per hour, so two hours can be meaningful. It's only really a problem though if you need ~300 miles of range added in a 6-hour window.

                  Typically that isn't how people charge though. And, the utility tariffs are likely to add a demand charge if that is how people start acting, which will create enough of a disincentive to charge at full current that it isn't a big deal.

                • by cob666 ( 656740 )
                  Anyone who has an EV and has to drive 70% of their vehicles range to get to work is just asking for problems. It's not even comparable to having to drive near the limit of your regular car's tank capacity because it takes just a couple of minutes to stop and fill up the tank.
              • Oh, so you not only need to get an emergency call, but *also* have to live too far away from your place of work that you can't even make it on 70% charge? How contrived an example do you need to come up with for this to be a problem?
                • by Mal-2 ( 675116 )

                  I don't know, and I proposed a solution to said problem anyhow: charge to whatever the range of a back-to-work drive is, then defer the rest until off-peak hours. I know it's bullshit. Also, it would just be one more unlikely situation in a heap of others which have absolutely nothing to do with vehicle charging, yet could just as well stop someone from getting to work. Like a fire in the Sepulveda Pass stopping both the 405 *and* Sepulveda Boulevard. Sometimes shit happens, and you can only afford so much

                  • I don't know, and I proposed a solution to said problem anyhow: charge to whatever the range of a back-to-work drive is, then defer the rest until off-peak hours. I know it's bullshit. Also, it would just be one more unlikely situation in a heap of others which have absolutely nothing to do with vehicle charging, yet could just as well stop someone from getting to work.

                    For the EV to gain acceptability, the convenience, versatility, range and thoughtless operation need to be on par with today's current ICE

                    • Except for the Average american single family home, most of those issues are really solved.

                      If you've got a garage where your car is parked for 8 hours a day and your round trip commute is less than half of your range, then you've got to come up with some really contrived situations for it to break. We've got a PHEV and it's currently 4x cheaper to drive it on electricity than gasoline. Given that gas prices will generally rise and the lowest electricity prices will likely fall further (though i expect pe
                    • by dryeo ( 100693 )

                      For the EV to gain acceptability, the convenience, versatility, range and thoughtless operation need to be on par with today's current ICE vehicles.

                      People aren't going to want to sign up for more pain in the ass....they're going to want the thoughtless commodity convenience they currently have now with future vehicles.

                      You can't blame them...

                      Or the cost savings worth the hassle.
                      You have a good paying job without the expense of a family somewhere relatively cheap to live, so convenience is more important to you then cost.
                      Where I live, one of the most expensive places worldwide, gas is consistently the most expensive in N. America and electricity is dirt cheap, creating a huge demand for EV's, even with the hassle.
                      With the oil companies more interested in profit then expansion, how hard it is to build more refineries, gas prices are likely to rem

                    • Except for the Average american single family home, most of those issues are really solved.

                      If you've got a garage where your car is parked for 8 hours a day

                      Well, over the years, growing older and moving around the US a bit, I've come to find out that single family homes with off street parking aren't as much the norm for the average American as you might think.

                      Aside from those many, MANY folks living in apartment complexes that don't have private, covered parking....even many with single homes may not

                    • For big apartment complexes I think you just need to legislate that they install chargers for tenants who ask and that they don't mark up the cost of electricity beyond what the tenant pays in their own unit. I'm sure the landlords who balk at installing smoke alarms and fire escapes will cry foul about it, but I'm a bit low on sympathy for them.
                    • For big apartment complexes I think you just need to legislate that they install chargers for tenants who ask and that they don't mark up the cost of electricity beyond what the tenant pays in their own unit. I'm sure the landlords who balk at installing smoke alarms and fire escapes will cry foul about it, but I'm a bit low on sympathy for them.

                      Hmm..I've never seen an apartment complex with "fire escapes"...

                      At least not modern ones with parking lots. I"ve seen fire escapes on TV when looking at old build

                • *And* you need to have no charger at work and your long drive to/from it needs to not pass near any superchargers.

                  I'm sure it'll be a problem for somebody, somewhere, but so are breakdowns and those are more likely in an ICE car due to their engines being more complicated.

                • *And* you have to walk uphill in the snow both ways to reach your car.

            • Part of the smart grid though is you tell your car "I need to be charged by whatever AM and the car and the grid can sort that out. People who need to leave at 6 get charged earlier because people who leave at 8 can eat those 2 extra hours of grid capacity.

              This sounds like a whole most more pain in the ass, planning needed....a hell of a lot more than needed for current ICE vehicles.

              The parity you need to get to, is to make the EVs as convenient and thought free for operation as the current ICE.

              There is

              • Is it though? For the vast majority of people this will be something they setup when they buy the car and not adjust for the most part and the idea of a smart grid is that the nitty gritty details are automatic.

                Fact is for the average commuter with a total daily trip of 20-60 miles round trip they simply will cut 90% of their trips to the petrol station altogether since they are topped up everytime so in a way many people simply are not going to have to worry about "i need to leave early today and go out of

                • Well, as you said towards the end of you reply, maybe more practical for most in the 2030's perhaps.

                  ...and the idea of a smart grid is that the nitty gritty details are automatic.

                  And this might take care of it. ON the other hand, I've been in agreement with other folks on other threads, that I'm not really comfortable with ceding control of such things to corporations, or even the government ...whomever owns/runs the "smart grid".

                  Fact is for the average commuter with a total daily trip of 20-60 miles round

                  • those are all true and thats why the infratructure has to be in place.

                    If you are doing weekend 400 mile trips and stopping for 30-40 minutes versus 10 is a problem than an EV today is probably not the right car for you, or at least as a primary.

                    If having one vehichle for long trips with short refill times is cricitcal to your lifestyle than an EV today is probably not for you.

                    I think on the whole though you are talking about not so much edge cases but out of the norm stuff for sure. Just like people with b

        • No amount of code is going to solve the problem of lack of capacity.

      • So the new peak is at 12am instead of 6am, that's gonna make all the difference.

      • Did you like the Volt? I felt like they marketed that in the dumbest way possible. If they'd sold it as a plug-in EV with a range extender gas engine "just in case" they'd have sold way better.
        • No, overall the Volt was a piece of crap. I'd say that Chevy nailed average to below average on every single part of the car.

          Running only on battery it was fine and I enjoyed it, for the 30ish miles it delivered on that.

          With the engine running the car would vibrate badly, to where the rear-view mirror would vibrate out of place. The Volt has had every part of the car lightened to accommodate the combined weight of an ICE and Electric drive. The roof of the car is plastic, and would shake horribly with th

    • Even worse (Score:2, Interesting)

      by gillbates ( 106458 )

      Programmable thermostats have been available since the 80's.

      If your power grid takes more than four decades to meet the challenge of new technologies, you have much bigger problems than electric vehicles.

      The issue is AC power. AC made for a cheaper grid, but at the expense of increased complexity for the operator. While the grid could have been built with DC, it would have cost more to step up / step down to transfer over long distances. Now we have a grid - which for all practical purpose - is too

      • Re:Even worse (Score:5, Informative)

        by aaarrrgggh ( 9205 ) on Thursday July 14, 2022 @08:48PM (#62703966)

        WTF?!

        There are many things about AC power that make it easier for the grid operator, and the things that are slightly more complex have been solved for about 100 years (and more elegantly solved for over 20 years). Frequency and phase-angle load sharing is actually more stable than voltage based load sharing, and an order of magnitude more responsive and controllable.

        Now, should homes have central AC:DC converters? Still no. A centralized DC converter sized to accommodate smaller loads would need to be about 1kW for most homes, and would have a minimum voltage of 100VDC for voltage drop, leading to more point-of-use DC:DC converters. 100VDC is actually harder to work with than 120|240 VAC due to arcing issues and contact life.

        Ok, last chance... should utilities use DC power for transmission? MVDC is out because it would have to duplicate existing MVAC lines, and add more remote equipment. HVDC does serve a purpose though, and is used heavily (where it makes sense). But that doesn't get back to any of the benefits of using DC power beyond saving one wire: integrating batteries still needs voltage converters and a LVDC:HVDC boost converter is still going to be far more complex than a LVDC:MVAC:HVAC conversion.

      • While the grid could have been built with DC

        No. No it could not. That's an incredibly stupid idea.
        You could probably run your entire house on DC, but that's about the limit of how far it is practical.

      • Re:Even worse (Score:5, Informative)

        by serviscope_minor ( 664417 ) on Friday July 15, 2022 @03:12AM (#62704452) Journal

        Programmable thermostats have been available since the 80's.

        WTF? No, they've been available much longer.

        If your power grid takes more than four decades to meet the challenge of new technologies, you have much bigger problems than electric vehicles.

        Eh? The problem is not mechanical timers, it's that a small number of manufacturers are selling new timers with very precise, continuously set clocks with default times preprogrammed. This means there is a large spike of many users coordinated to the second. This is the complete antithesis of how humans control things and has only become a thing in the last few years.

        The issue is AC power. AC made for a cheaper grid, but at the expense of increased complexity for the operator.

        Oh FML a DC loonie. No. Everything you are saying is objectively wrong.

      • by AmiMoJo ( 196126 )

        The reason that the grid is AC is because back when the grid was being built there was no practical way to convert large amounts of power to high DC voltages and back down again. Solid state switch mode converters didn't exist, and it wasn't until many decades later that they got good enough to handle grid levels of power.

        Conversely converting AC is very easy, you just use a transformer which is two coils of wire. It also means you can use the output of your generator directly, instead of having to rectify

    • Not really an issue. You can set your car or charger to come on at a certain time, like 10pm-4am when power use is very low. Plus if someone has a typical electric forced air furnace that may draw 60-70amps so this 6am power surge is much worse than some EV charging late at night. Add these new on demand or tankless water heaters, those can pull 80amps so add that power draw happing about 15 minutes after the heaters all turn on. Also with a 250-300 mile range EV drivers don't all charge every day, maybe 1
    • Incorrect.

      The issue is that none of this shit is "smart" yet. It might be able to do some basic usage statistics and change some timing, but that's not smart.

      If this was actually a "smart" thermostat, we could tell it, "yes, they want it to be warm at 6am, but we're going to need a gentle 2 hour ramp-up to do that". That's actually smart. It's not smart to operate independently from a system you depend on!

      Same with electric cars. Many already support delayed and scheduled charging. However, they aren't quit

      • by Mal-2 ( 675116 )

        Any change in temperature is accompanied by a corresponding change in the amount of heat lost from the system. If you're letting the house settle 20 degrees above ambient, you will lose less heat than the exact same house at 21 degrees above ambient. So starting the change any earlier than necessary is wasteful from an individual point of view. Standard Prisoner's Dilemma stuff.

      • Yes, if everyone pluged in at 6pm after driving 300+ miles on absolutely empty batteries, it would fuck the power grid up. I will not dispute that! But that's not what happens in practice.

        But they WILL happen and the grid everywhere needs to be able to handle those occurrences.

        It is quite reasonable during any given year, that in areas of the US, you will have mass evacuations for fires, hurricane, etc.

        Let's take a hurricane like IDA or Katrina...you have from New Orleans alone, a mass exodus....then, in

    • by fermion ( 181285 )
      Out power grid is optimized for peak demand. So extra power is just unused or even just drained off. To meet the needs of the future we are going have to engineer to meet average damage and the over engineer storage so we can meet not only peak demand but extraordinary demand. If this storage can be localized even better.
    • Yes; if the tariffs incentivize cars to all start charging at midnight and be finished before 6AM the grid will not respond well as most of them are set up today. The "ready by" feature setting 6AM as the target isn't much better, but has a lower up-ramp (just a faster down-ramp typically*).

      So, the tariffs adjust. If they are smart, they widen the off-peak tariff window and incentivize EVs to be demand-responsive to a utility signal that softens the ramp-up, but ensures that everybody will be able to meet

    • by tlhIngan ( 30335 )

      Massive simultaneous demand is a problem utility companies are going to have to deal with one way or another. Imagine every car you see on the highway in rush hour traffic, arriving at home and plugging in. Today's grid would shit itself.

      And chances are, you charging doesn't have to be sudden an immediate. Most people will get home around 6-8PM, put their cars on charge, and their cars will sit there until 6AM or so when they head out to work.

      A smart charger will learn these sorts of schedules and then tell

    • It seems that when I set my Model 3 to charge at a certain time, thereâ(TM)s a randomized start time of a few minutes where it actually starts, apart from the slow ramping up to 11kW.

      Still it could become a problem but as with everything else, solutions are already being sold. You can buy home EVSE that looks at the current tariff and starts charging at the cheapest time and take your own solar production into account.
      On regular days, I use 16% of the battery.
      The last 2 days. My electricity were almost

  • Evidence showed that residents remain confused about how to operate their thermostats and are often unable to program it,

    This is what you get for your overpaid hacks. Can't even develop simple, step-by-step instructions on how to set a time for the temperature to rise or fall.

    We need fewer programmers and "designers" and more people who can translate monkey scat into English.

    • by Xenx ( 2211586 )
      While I don't doubt some devices are harder to program than others, I know from my experience in technical support that the problem is often the customer and not the product. People aren't good at even simple instructions when they have no interest. The number of times I literally have to explain a power button to a customer is higher than the average person would think.
      • I had many issues installing my 2 Ecobees but found their tech support to probably be some of the best I've ever experienced. But i think they were well practiced with a huge design flaw in the product - the internal temperature sensor is hugely influenced by the heat the own units gives off. So they are good at telling you how to work around it.
    • by Powercntrl ( 458442 ) on Thursday July 14, 2022 @06:44PM (#62703698) Homepage

      Working in the trade, the most common question I get asked about smart thermostats is how to turn the smart shit off. Seriously, if it's a household with more than one occupant not on an identical work schedule, the "smart" feature just means whoever is unfortunate enough to be at home during the energy saving part of the cycle is just going to be uncomfortable.

      I also don't buy for one second that you can sacrifice comfort in the middle of the night either, unless you like waking up at night with the sheet soaking wet and a freight train runnin' through the middle of your head.

      • I came here to post the same thing. I have two Honeywell programmable thermostats in my house. One for upstairs and one for downstairs. Fortunately it was easy to put them in "hold" mode. The temperature is maintained 24 hours/day. I'm in Florida where it's normally a hundred degrees out. My entire house is electric and the bill neve exceeds $250/month and usually in the $150/month range.

        Do these thermostats even save money. Even if you did leave the house from 9-5, it takes a few hours for A/C t

      • the most common question I get asked about smart thermostats is how to turn the smart shit off.

        I have a programmable thermostat, but have that "feature" disabled. I use fixed min/max temps with the system auto-switching between heat/cool as needed.

        I live in S/E Virginia and have a 3-ton, 17 SEER, 2-stage (single compressor), electric heat pump with third-stage electric strip heat and a variable-speed air handler. This static thermostat setup seems to work just fine. Granted I haven't set my min temp very high and max temp very low, but I'm generally always comfortable.

        Supposedly, in programmed

        • If you can avoid the strip heating, it will save. Strip is very expensive to operate. You may already be avoiding strip by ramping the temp up a degree or 2 at a time when you get home. You might even be able to set a really high delta T in the TStat installer programming for strip heating to come on. If it is a carrier TSTat, just go to the service menu and hold the button for 30 seconds to get into program mode. I've got gas so not sure what you'd need to do. The decision of whether to run low/high or str
      • Smart temperature control requires easily variable capacity control-- a static / PWM controller on a heating element or inverter on a compressor (and electronic modulating expansion valve).

        There are many things that impact the perception of comfort though, and there is always some room to work where you can stay in the comfort zone on the shoulders of sleeping hours.

    • If they think an ecobee is hard to program, they should try to install one.
    • Setting the clock on a VCR was remarkably easy, yet plenty of people still struggled with it, so the VCR blinked 12:00 eternally. There's a significant group of people that will always be easily defeated by even the easiest technology, no matter what era
    • "residents remain confused about how to operate their thermostats and are often unable to program it,"

      I have to get out the directions when I want to change the timing. Push this button, hold that one, rotate counterclockwise while standing on left foot, then the time ticks up one minute until it jumps ten minutes, then rockets on to twenty minutes per second.

      Added to that I only have to change it twice a year, so by the next time I've forgotten the ritual.

      So I have developed the cunning plan of leaving the

    • by PPH ( 736903 )

      ... customers took a look at the default settings, figured that they were pretty good and left them alone. Or not worth the trouble to change.

    • Ok, design something easy and intuitive where a single button can set everything. No, you can't have a second button, that would cost 5 cents more and we can't have that.

      I also need it finished by tomorrow because you can't cost more than 50 bucks for that whole design either. Because our customer wants cheap, not functional.

    • Dunno how smart these are, but mine says "you want it to be warm by 6.30am", so it starts up at a variable amount of time before that, based on how long it took to heat last time, what the outside temperature is, etc. I'll bet my thermostat never comes on at the same time in two rooms, never mind at the same time as anyone elses.

      Here's another point: Nest/Hive etc are "single zone" - that is they operate on the whole house at once. It's a whole lot simpler to develop a product like that than to make a multi

  • Simple fix (Score:5, Interesting)

    by schematix ( 533634 ) on Thursday July 14, 2022 @06:51PM (#62703720) Homepage
    Ecobee should change their firmware to follow the schedule but with a +/- 30 second random schedule delay. That alone will smooth the peak out. If you google around you can find stories about how the power grid in the UK used to work with their TV networks to know the timing of commercial breaks for major sporting events. Hundreds of thousands of brits simultaneously turning on a 230V hot pot for tea water at the same time creates massive energy demand issues and you need to be ramping at the same time the load is going up, not trying to catch up to it.
    • Looking long term, 1M+ people with smart thermostats will still wreck the power grid on +/- 30 seconds. It should be +/- 30 minutes on schedule randomly with no user control.
    • The American version of this is everybody flushing their toilet at the same time when Superbowl halftime starts.

      Perhaps another simple solution would be for loads that are not very time-sensitive (heating) to wait to turn on if they detect a sag or slight brownout in the power voltage. A bit like CSMA/CD in networking.

      • Does that mean that on game day, our sewage actually makes it to Washington with a single flush? Does crowdsourcing actually create synergy in the sewage system?

        I was always told you had to flush twice to get it all the way to Washington.

        Asking for a friend.

    • If you look at the ZigBee Smart Energy spec (dot dot, matter or what ever they are calling it this year) you will see it has a requirement for randomization. I wrote it. Synchronization of demand is a big strain especially when it's inductive loads like AC units. But there is an even bigger way to reduce stress on the grid that smart thermostats can do. If we had true time of use pricing (see what the hourly rates are in Ontario Canada - http://reports.ieso.ca/public/... [reports.ieso.ca]) then people would be motivated
    • by AmiMoJo ( 196126 )

      It would probably need to be more than a 1 minute window, but the principle is sound.

      They could go one better though. Allow the energy company to make the consumer an offer. If the energy company can turn up the thermostat up to 30 minutes early, they get a discount on their bill that more than covers the extra energy used.

  • by WaffleMonster ( 969671 ) on Thursday July 14, 2022 @07:08PM (#62703770)

    Especially in the winter the best course of action when using an air source heat pump is to pick a temperature and leave it.

    The reason is if you set the temperature back during the day when you are gone when you return at night when it is colder the efficiency drops to not only re-heat the air but also the solid mass within the home. This is especially true as conditions get colder and you creep closer to the balance point. Recovering from setback in very cold conditions for those on all electric heat means higher contribution of resistive heating at enormous cost.

    Even in a best case scenario with traditional gas heating and substantial +8F setbacks the seasonal savings is less than 10%. The green themes with substantial savings are mostly marketing slogans. There is no potential for anything approaching 30% savings using a smart thermostat. To achieve any real savings the temperature needs to be reduced and left there. From the Canadian study they only got 13% with an 11F day and night setback using gas heat.

    https://nrc-publications.canad... [canada.ca]

    • I noticed a similar phenomenon in Florida when I was working on my own Arduino-based HVAC controller & left it running (and logging) on a timer at one point for a few days after I found a bug & didn't have time to fix it immediately.

      The sun might go down around 8-8:30pm in the summer, but the A/C load doesn't really start to fall until around 4-5am... the AIR temperature outside might fall by a few degrees after sunset (or not... occasionally, we'll get wacky nights here when it's actually hotter at

    • But I want it colder at night than during the day. So that's how I have, do and will set my thermostat.
  • The user is too dumb to program the programmable thermostat he bought. It is the dumb user, too dumb to program a bloody thermostat, but buys the gadget he can't use anyway, pissing of cash, who is straining the grid not the smart device. That dumb user will find ways to strain everything with or without smart devices.
    • I'd like to see an experiment where these thermostats (and other smart things) do not have any default programming, and the user has no other choice than to go through the settings.

    • The user installs it or has it installed, finds it turns on at 6, and this works fine for them so they don't change it. I fail to see the stupidity in the process.

  • These silly things are connected to the Net 24/7 anyway so offer a discount for usage that allows the power company to defer the usage.

    They might need a signed blob from the power company for them to trust the metering, but that's just negotiating the details.

    They don't even need smart meters to get within the "good enough" range.

    They just need to decide to get started solving the problem.

    • by Isarian ( 929683 )

      I have a Nest 3rd Gen thermostat and in Illinois ComEd used to do exactly this. There was an opt-in program where during peak load you gave the utility permission to reduce air conditioning usage to smooth out the curve, and if you opted in you could get a small credit on your account. They killed the program after just a few years and I've never understood why. It seemed to me like grid coordination would be one of the major benefits of smart devices that handle home utilities like a thermostat.

  • by Tony Isaac ( 1301187 ) on Thursday July 14, 2022 @10:11PM (#62704126) Homepage

    As a person who has spent his lifetime in technology, I hate monkeying with thermostat programming. Most of them are as intuitive as a sprinkler system controller. One must continue to update it as your lifestyle or habits change. Or you can pay hundreds for a "really" smart thermostat, and you still have to monkey with it constantly.

    No thanks, I'll just keep my simple up/down arrows and leave it set at the temperature that works. Sure, I could save a few bucks a month, but is it really work all the constant tweaking?

  • The thermostats don't start at 6am. They start *before* 6am so that the target temperature is reached by the requested time. They supposedly use the history of how long it took from previous cycle(s) to change the temperature xx degrees and use that as a lead time. The problem they're talking about already.... solved?

    Are the authors of the paper really that unfamiliar with what they are researching? My smart thermostats have done this for years. If I set 75 cool at 5pm the system cranks up around 3:45ish to

    • My smart thermostats have done this for years. If I set 75 cool at 5pm the system cranks up around 3:45ish to start cooling from 80->75. It usually hits the target temp around 4:45-4:50pm.

      I didn't see anyone else post this. Am I the only one that RTFM for my thermostat?

      Does it really take that long to cool down your house? Do you live on the equator?
      Anyway, I don't have a "smart" thermostat, but my programmable one works great, so I have no intention of hooking it up to the internet for no reason.

      • Yes, sadly. Central Florida + No tree shade + block walls. My Honeywell wasn't internet connected but still did those functions. I take my measurements of when it ran from z-wave sensors I have at the electrical panel and temperature sensors throughout the house.

        Also, it takes about 12-15 minutes before the AC even reaches optimal cooling

  • by MagusSlurpy ( 592575 ) on Thursday July 14, 2022 @11:56PM (#62704290) Homepage
    There is no way in hell 40% of American homes have smart thermostats. We can't even get 40% of Americans to fucking vote. No way they are shelling out 100+ dollars for more future e-waste that knows they just left work and need the house temp dropped three degrees.
    • If you walk into a hardware store and peruse the HVAC department, you will likely find they carry one dumb thermostat and three or four smart ones. Most new home construction probably features a digital thermostat, since they are barely more expensive than a traditional type.

  • Virtually all European and UK domestic heating systems have used a "Programmer" - usually a programmable time-switch for heating and hot water - to turn of the system over night and perhaps during the midweek daytime if all the inhabitants are working. AFAIR the EU mandated such systems, including zoned heating (to allow say bedrooms to have different settings to living rooms) something like 15 years ago. Of course these programmers are just running independent mechanical or electric clocks, and they're i

  • It's the built-in clocks that are too good nowadays.

  • Change it so that the turn on setting has a 5 minute random offset.

    As for knowing how to set it up, that is simply bad GUI. They should connect to your phone etc with a good GUI and that problem vanishes.

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