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Take a look at the major power consumers in your house. You have HVAC. Refrigeration. Your washer. Your dryer. And your dishwasher. Each one of those things i

Take a look at the major power consumers in your house. You have HVAC. Refrigeration. Your washer. Your dryer. And your dishwasher. Each one of those things is inherently a form of energy storage, because you don't need any of those to start up or stop at the same milisecond where you flip the switch. What's left? Lighting. Entertainment. Communication. All of these you do expect to consumer power on demand without any time slack. But the major loads I listed above can defer to the minor loads that demand that kind of priority. So with a little TCP/IP to coordinate activities around your house, your need for power storage declines considerably.

thatwebdude 9y ago
Good point, but I'm not always home to do the laundry at the most opportunistic time. Doesn't a refrigerator run most efficiently if it cools continuously? I'd hate for my milk to spoil. I know that Nest has an option with some electric providers to integrate with their demand needs already for something like this; I have it enabled, but they've yet to utilize it. I could totally see a dishwasher utilizing this, it makes the most sense, assuming I had enough extra dishes and space for the relatively small inconvenience it'd provide.
- goda90 9y ago
  A well designed refrigerator can hold temperatures without "turning on" for quite awhile if the door isn't opened and warmer food placed in it in that time period. The insulation is "passively storing" the temperature differential.
  - thatwebdude 9y ago
    Yeah, "continuous" was a bad choice of word.
- ocschwar 9y ago
  Refigerators commonly have a compressor to cool the freezer, and then a heat exchanger to equalize between the freezer and the fridge. So the freezer can store energy by working extra hard bringing things down from -5C to -20C whenever it's expedient, and the equalizer keeps the fridge in its usual temperature range. Nothing spoils, and you don't even have to notice.
  - thatwebdude 9y ago
    It still isn't controlled by a timer or switch, though. That's the point I was opposing.
    - halomru 9y ago
      But there's no reason it can't be. So far there just wasn't a reason
      - thatwebdude 9y ago
        Food safety dictates a minimum chilling temperature, we can't override that without sacrificing health. We can make fridges/freezers more efficient and insulated though. My deep freezer (according to Energy Star) takes $24 a year to freeze my food. That already seems extremely efficient.
      - askvictor 9y ago
        Yes, but it's not going to be retrofitted onto existing fridges. You'd need to replace most of the fridges in the system.
    - deleted 9y ago
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- halomru 9y ago
  Today's washing machines already have timers to start in X hours (at least mine has, and it's not exactly top of the line). Once consumer electricity prices reflect the actual electricity price at that moment new models would quickly contain internet-connected logic to start the washing cycle at the point in the next 24h with the lowest predicted electricity price. If you integrate washing machine and dryer into one mashine, the cost-savings from electricity would be even bigger with very little convenience lost.
  - thatwebdude 9y ago
    Absolutely, although I don't know how they handle wrinkles, though without an auto-fold/hang feature (that'd be so cool!).
    - mhandley 9y ago
      Our drier tumbles the dry clothes for a second or two every five minutes or so for hours after the dry cycle has finished. This goes a long way to avoiding the clothes getting too wrinkled waiting for us to unload it.
      - thatwebdude 9y ago
        ...my dryer simply doesn't go long enough to keep them wrinkle-free.
- deleted 9y ago
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vinceguidry 9y ago
For household appliances to be used in this manner, they would have to be completely automated. Sure, I could choose to run my laundry cycle at 8pm rather than 5:30pm, but the convenience factor of doing it when I want to do it is going to trump the pennies they'd give me to wait, every single time. Now, if all I had to do was dump all my dirty laundry in a hamper, and it automatically sorts it and folds it after it's done washing, now that's something I don't care about anymore and can just let a program decide when it wants to accomplish each step.
- ocschwar 9y ago
  > Sure, I could choose to run my laundry cycle at 8pm rather than 5:30pm, but the convenience factor of doing it when I want to do it is going to trump the pennies they'd give me to wait, every single time. However, the heating element in your dryer doesn't have to be run like that. You start the dryer, and it starts tumbling your clothers with the motor, and blowing some air with the fan, but the heating element can turn on and off in coordination with the rest of your house, and you wouldn't even notice. Also, most of us run a load just before going to bed, and shuffle it to the dryer in the morning. Do you care if the washer takes a little while before starting up while you're sleeping? I sure don't.
  - settsu 9y ago
    > Also, most of us run a load just before going to bed, and shuffle it to the dryer in the morning. Not if you care about the longevity of your clothing and mildew in your washer. I don't know anyone who does this routinely on purpose.
    - wernercd 9y ago
      How much mildew is going to build up if it starts an hour or two later? Or sits in washer for a few hours after finish? Waiting days? Sure... random-internet-answer(s) seem to hover around 24-48 hours before mildew becomes an issue... So, sitting over night and then maybe a few hours before the dryer starts (Assuming that, it too, would be on a timer) shouldn't be a major issue.
moron4hire 9y ago
> Each one of those things is inherently a form of energy storage, because you don't need any of those to start up or stop at the same milisecond where you flip the switch. You lost me. I don't understand how that connects.
- halomru 9y ago
  In a way a dishwasher is storing energy in the form of clean dishes. Now instead of storing electricity to run the dishwasher whenever, you simply run the dishwasher when there's an electricity surplus
  - ocschwar 9y ago
    In particular, when the dishwasher's in the drying phase. Do you really care if the heating element turns off here and there at that time? Probably not.
nradov 9y ago
Running a clothes dryer unattended is not safe. Those appliances are among the more common causes of house fires. And as a practical matter, busy parents with small children can't defer running the washer and dryer. It needs to finish in time to fold and put away the clothes, and you often need to run multiple loads.
- ocschwar 9y ago
  > Running a clothes dryer unattended is not safe. Those appliances are among the more common causes of house fires. A smart-ified clothes dryer is more attended to than a conventional one. >And as a practical matter, busy parents with small children can't defer running the washer and dryer. It needs to finish in time to fold and put away the clothes, and you often need to run multiple loads I'm one of them. I can't always defer, true enough. But I can often enough.
  - deadbunny 9y ago
    > smart-ified I don't care how smart your dryer is, if it catches on fire it's not going to do shit.
    - ajarmst 9y ago
      Well, if you equip it with a halon suppression system in a sealed and heavily sensored room, it might. Of course, now your dryer is your single most expensive possession by an order of magnitude. Which always seems to start being the problem when people propose "smart" solutions. "Well, first we need a class IV AI and on-demand local fusion energy, then everything gets easy..."
      - Dylan16807 9y ago
        I mean, you could just put in a few more heat sensors.
        ajarmst 9y ago
oceanplexian 9y ago
Your house!? I think this misses the elephant in the room. Large industrial machinery. Data centers. Manufacturing. Electrified transportation. At the place I work, we use more electricity in a single, 19 inch high density server rack than your entire neighborhood. We have rooms full of batteries like the Tesla Powerwall and would be lucky if they could operate for 10 minutes.
- rb808 9y ago
  > Large industrial machinery. Data centers. Manufacturing The good thing is these loads are relatively constant and predictable. One reasons electricity is expensive is the peak loads are much higher than a regular day - you need a power station (or storage) on standby for that hot day when everyone suddenly runs their AC continuously all afternoon. >Electrified transportation This is different and a good opportunity that the article talks about. Esp a plugin hybrid could charge on windy sunny days and not charge in the peak times as above.
- deleted 9y ago
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- adrianN 9y ago
  Huge loads like Aluminium smelters are already "smart" and cooperate with the electricity providers, so there is not as much left to gain there.
  - askvictor 9y ago
    Yes and no; you can't just switch off an aluminium smelter with destroying it; it takes quite a bit of time to ramp it down. I think that for forecast high demand they shut down production in a planned way.
- philipkglass 9y ago
  In the United States, more electricity is used residentially than commercially or industrially (4.8, 4.6, and 3.2 quads respectively in 2016): https://flowcharts.llnl.gov/content/assets/images/energy/us/Energy_US_2016.png https://flowcharts.llnl.gov/content/assets/images/energy/us/...
xexers 9y ago
Don't forget "water heating". That could be done more dynamically than it is now... and water heating makes up 9% of household electricity usage: https://www.eia.gov/tools/faqs/faq.php?id=96&t=3 https://www.eia.gov/tools/faqs/faq.php?id=96&t=3
- WalterBright 9y ago
  True. A water heater tank can keep the water hot for a full day with no power. Even two days will still get you a warm shower. I discovered this during power failures :-)
- jopsen 9y ago
  It constantly surprises me how many places have electrical heating. I grew up in northern Europe where remotely heated water is the norm. https://en.wikipedia.org/wiki/District_heating https://en.wikipedia.org/wiki/District_heating In terms of efficiency, using excess heat, etc. electrical heating is utterly horrible.
- ams6110 9y ago
  Solar heated water is probably much more efficient than solar generated electricity.
agumonkey 9y ago
What about fridge heat harvesting btw ?
- twothamendment 9y ago
  I had a crazy idea to relocate the compressor and coil from my fridge to the mechanical room in the basement directly below it. It would cut down on noise and should make the fridge more efficient because it wouldn't be dumping its heat under itself. Once the heat is dumped in the mechanical room, a heat exchanger around the pipe to the hot water heater would have to help a bit. Even in the summer water out of the ground is pretty cold and anything to take the chill off would be a bonus.
  - agumonkey 9y ago
    Basically what I thought. I googled and saw a few "fridge harvesting papers" I should read (or you ? .. ?) - http://www.irdindia.in/journal_ijmer/pdf/vol4_iss1/9.pdf - https://info.ornl.gov/sites/publications/files/pub31294.pdf - https://www.acoustics.asn.au/conference_proceedings/AAS2009/papers/p28.pdf
matt_heimer 9y ago
So you want priority queuing for power consumption. I understand it would be able to eliminate some spikes for my individual house but my overall usage doesn't go down. The article is really about the grid and not an individual house. If every house in my town had priority queuing would the hourly consumption really change? Maybe that last dryer or dishwasher load of the night could be time shifted but you can only delay refrigeration or clothes washing so long withing either spoilage or killing your throughput.
- greglindahl 9y ago
  Yes, smart grids can really change hourly consumption. As an example, imagine a world where 1/3 of the cars are electric, and they're long-range cars like the Bolt or Tesla, which only need to be charged every couple of days, not all of the time. A system that looks at the solar/wind forecast and charges your car at the right time can make a huge improvement to the grid on a time-scale of days.
  - twothamendment 9y ago
    I still find "long-range" electric vehicles to be an oxymoron. A Bolt @ 75 mph can only make it 190 miles. I'm not sure that is enough to get me to a qualified mechanic and back and it sure doesn't compare to the nearly 500+ miles I get on fuel. I can't afford to drop $30,000 on a car that I can't take on a road trip. I think the progress made on electric cars is exciting to watch, but I have to laugh when they talk about "long-range". http://insideevs.com/instrumented-test-of-chevrolet-bolt-190-miles-of-range-at-steady-75-mph/ http://insideevs.com/instrumented-test-of-chevrolet-bolt-190...
    - greglindahl 9y ago
      You're getting off-topic, but, Tesla owners take road trips using the Supercharger network all of the time. Instead of focusing on your personal preferences, maybe you could also take a look at the actual behavior of early adopters?
twothamendment 9y ago
"Each one of those things is inherently a form of energy storage, because you don't need any of those to start up or stop at the same milisecond where you flip the switch." Using an appliance later is no more a form of energy storage than me "saving" air by holding my breath. Reduction in peak demand <> Storage. On a hot summer day when I'm cooking in the house, running a load of dishes and trying to cool the house to a reasonable temperature - all before the guests arrive - Should the A/C wait for the dishwasher, which waits for refrigerator, which waits for the oven? Not in my house. Storage - I'll gladly take some of that so my lighting and communication can be powered when the power is out. In that situation, the rest of those big loads can wait.
- btowngar 9y ago
  Load scheduling is precisely equivalent to energy storage. You store electrical energy with the intention of consuming it later. Load scheduling just makes this explicit. In fact one of the benefits of scheduling over storage is that there's no extra losses due to charging / discharging the battery.
  - twothamendment 9y ago
    "One of the benefits of scheduling over storage is that there's no extra losses due to charging / discharging the battery." Loss - that should be one of the first clues that scheduling is not storage. Any electrical storage in my lifetime will have loss, I can accept that. I'll give you scheduling as storage when it comes to a freezer or hot water heater. Why? Electricity was converted to something that can be stored. There is loss - a clue to real storage taking place, not pretend scheduling "storage". If I heat a tank of hot water and want to shower an 3 hours later after I've turned off the power to my house I'll have a hot shower (in the dark). Try the same thing with an electric clothes dryer. Plan to run it in 3 hours and turn the power off and see how well it works. What? The dryer didn't store any electricity? Storage, by definition, means you have something. When it comes to the grid, storage and scheduling can both reduce peak demand, bug scheduling is far from storage.
  - posterboy 9y ago
hwillis 9y ago
Back of the envelope math: Assuming a fridge has two cubic meters of air and twenty liters of water (the heat capacity of all the food and metal inside the fridge) and takes the temperature from 70 F to just above freezing (20 C difference), there's a heat storage of 472 watt-hours, or 1.6% of the average daily electricity consumption. A 100 gallon (380 liter) hot water heater that raises water from 50 F to 120 F (40 C) can store 17.6 kWh, or just under 60% of daily household power use. Of course this was gonna be huge, and its a good opportunity, since in the mornings a house will use 40-80 gallons with the showers. I'm not sure how much of that is actionable, though. The water would have to stay hot all night. The average newly built house in the US is 2600 sqft, which is 20,800 cubic feet with 8' ceilings. With a 45 F temperature change (25 C) the air in that alone is 5 kWh, which honestly surprised me with how big it is. You'll never want your house to be changing temperature that much during the day, of course. You'd get crazy condensation and whatnot. By the straight math this could cover 17% of daily usage- that could go up by several times due to the heat capacity of the objects and materials in the house, but down by 5 times since you wouldn't want your house changing that much in temperature. Water/heat capacity would be a pretty decent way to store a large amount of electrical load, but I think it's gonna struggle to catch on. In northerly climates you could combine the hot water and home heating, but those places will struggle much more to get cheap solar power, which is 2.5-3x more expensive in the winter. Meanwhile southern climates will have solar power at 70% the price of the rest of the country, and it tracks the summer power demand increase well- but it's way harder to store your energy in cold water. Other than that it makes sense: while you're at work, the system cools down a large insulated tank of water, which it then circulates to a heat exchanger right before you come home. You can't use it for hot water though, and it'll be a lot bigger and more expensive than an AC. Basically it would be good for load leveling, but not overnight storage or seasonal storage. There aren't many indications that load leveling is actually a real problem. It'll probably just be solved with a smarter grid.
- deleted 9y ago
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- wavegeek 9y ago
  > By the straight math this could cover 17% of daily usage If you are heating from room temperature to RT+50C the actual energy extractable (as electricity) from that heat is only about 15% of what you put in https://en.wikipedia.org/wiki/Thermal_efficiency https://en.wikipedia.org/wiki/Thermal_efficiency. If you used the energy purely for heating you would in theory get it all back but the low temperature differential would mean in practical terms it would not work fast enough. You also need to factor in loss from conduction.
yourapostasy 9y ago
Once I started renting and eventually owning a house, it always drove me a little nutty to observe that many of those power consumers you cited are variations of a heat pump of one kind or another. I've always wanted to co-locate the heat output from the compressor of the A/C+refrigerator+chest freezer, dryer, and dishwasher into the same equipment space as my water heater, which uses a heat pump to extract that heat and cool the space at the same time. Any "overflow" heat I'd like to put into zeolite balls [1], and release back when needed for the washer, dryer and dishwasher to use. This is on top of the nuttiness I accrete after observing that foamed glass insulation that can put us up to terrific equivalent R-values (R-100+ pencils out if you intend the building structure to pass through several generations), and drop climate control operational energy costs 80-90% from current typical expenses, is a dead letter in the US residential market [2]. The amount of energy developed world practices and infrastructure throw away is mind boggling, once you view everything around you in energy flow terms. But like others are discussing in this thread, industrial and commercial energy use overshadows residential [3], over 60%. The low-hanging fruit sits there, because the ROI is typically faster or more bearable in those business-oriented contexts. I'll still pursue saving for and building a highly-insulated and -instrumented shell on my property once my house is paid off in a few years, just to scratch those nutty itches. [1] https://www.extremetech.com/extreme/130523-zeolite-thermal-storage-retains-heat-indefinitely-absorbs-four-times-more-heat-than-water https://www.extremetech.com/extreme/130523-zeolite-thermal-s... [2] http://www.greenbuildingadvisor.com/blogs/dept/green-building-news/foamglas-exits-us-residential-market http://www.greenbuildingadvisor.com/blogs/dept/green-buildin... [3] https://www.eia.gov/tools/faqs/faq.php?id=86&t=1 https://www.eia.gov/tools/faqs/faq.php?id=86&t=1
- tekacs 9y ago
  Speaking of everything being a heat pump, another interesting supplementary solution is https://en.m.wikipedia.org/wiki/New_York_City_steam_system https://en.m.wikipedia.org/wiki/New_York_City_steam_system
- asdfgadsfgasfdg 9y ago
  Be careful retrofitting insulation to a house. It can cause damp issues.
ouid 9y ago
The most inefficient time to run your AC is when it is hottest, aka the time that most people are running their ACs and are unlikely to stop running their ACs. Peak usage isn't as flexible as you seem to think. Also, hot days happen everywhere at once, so you can't even borrow power from other grids, because they are likely just as in need of power as you are.
- WalterBright 9y ago
  When it's hottest corresponds to when the solar panels work best, so there's that. Also, AC can be shifted. When power is cheap, use it to chill a tank of water or block of masonry, then use that coolness to reduce the AC load later. A tank of water can work just like a battery for HVAC.
  - ouid 9y ago
    It's almost like you've forgotten the original argument.
  - askvictor 9y ago
    Unfortunately, most solar panels point toward the equator for maximum overall power during the day. The highest demand for AC is in the afternoon; if panels faced West, they'd provide less overall power but more at peak times ( at least during summer)
  - nkurz 9y ago
    When it's hottest corresponds to when the solar panels work best, so there's that. Sort of. Away from the equator, days are longer in the summer, so one gets more total energy per day during the season when it's hottest. But hour-by-hour, the peak temperature usually happens later in the day (mid-afternoon) than the potential peak solar production (noon). More pedantically, solar panels actually perform worse when they are hotter: https://www.thegreenage.co.uk/article/the-impact-of-temperature-on-solar-panels/ https://www.thegreenage.co.uk/article/the-impact-of-temperat.... The ideal for solar power would be full sun and frigid cold. In the extreme (Andean mountain versus Australian outback) this difference in efficiency might be as large as 50% (+25% for the cold, -25% for the hot). I agree with you that the "battery" doesn't necessarily need to store electricity, and that pre-cooling some large thermal mass might be better than a traditional battery.
FooHentai 9y ago
>with a little TCP/IP to coordinate activities around your house, your need for power storage declines considerably. There's been far lower-tech solutions for this stuff for a long time now: https://en.wikipedia.org/wiki/Load_management#Ripple_control https://en.wikipedia.org/wiki/Load_management#Ripple_control https://en.wikipedia.org/wiki/Radio_teleswitch https://en.wikipedia.org/wiki/Radio_teleswitch
deleted 9y ago
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jlg23 9y ago
> Each one of those things is inherently a form of energy storage Uhm. Maybe from a purely financial point of view. Physically they are energy consumers. They do not store energy in any sense that would be relevant here.
alacombe 9y ago
HVAC and refrigeration are critical. The first to heat your home when it's -30degC outside, and the second to preserve food.
hyperpallium 9y ago
Some, like Refrigeration, are also a form of storage. Your fridge stores coolness, and only runs when it gets too warm.

thatwebdude 9y ago

Good point, but I'm not always home to do the laundry at the most opportunistic time. Doesn't a refrigerator run most efficiently if it cools continuously? I'd hate for my milk to spoil. I know that Nest has an option with some electric providers to integrate with their demand needs already for something like this; I have it enabled, but they've yet to utilize it. I could totally see a dishwasher utilizing this, it makes the most sense, assuming I had enough extra dishes and space for the relatively small inconvenience it'd provide.

goda90 9y ago
A well designed refrigerator can hold temperatures without "turning on" for quite awhile if the door isn't opened and warmer food placed in it in that time period. The insulation is "passively storing" the temperature differential.
- thatwebdude 9y ago
  Yeah, "continuous" was a bad choice of word.
ocschwar 9y ago
Refigerators commonly have a compressor to cool the freezer, and then a heat exchanger to equalize between the freezer and the fridge. So the freezer can store energy by working extra hard bringing things down from -5C to -20C whenever it's expedient, and the equalizer keeps the fridge in its usual temperature range. Nothing spoils, and you don't even have to notice.
- thatwebdude 9y ago
  It still isn't controlled by a timer or switch, though. That's the point I was opposing.
  - halomru 9y ago
    But there's no reason it can't be. So far there just wasn't a reason
    - thatwebdude 9y ago
      Food safety dictates a minimum chilling temperature, we can't override that without sacrificing health. We can make fridges/freezers more efficient and insulated though. My deep freezer (according to Energy Star) takes $24 a year to freeze my food. That already seems extremely efficient.
    - askvictor 9y ago
      Yes, but it's not going to be retrofitted onto existing fridges. You'd need to replace most of the fridges in the system.
  - deleted 9y ago
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halomru 9y ago
Today's washing machines already have timers to start in X hours (at least mine has, and it's not exactly top of the line). Once consumer electricity prices reflect the actual electricity price at that moment new models would quickly contain internet-connected logic to start the washing cycle at the point in the next 24h with the lowest predicted electricity price. If you integrate washing machine and dryer into one mashine, the cost-savings from electricity would be even bigger with very little convenience lost.
- thatwebdude 9y ago
  Absolutely, although I don't know how they handle wrinkles, though without an auto-fold/hang feature (that'd be so cool!).
  - mhandley 9y ago
    Our drier tumbles the dry clothes for a second or two every five minutes or so for hours after the dry cycle has finished. This goes a long way to avoiding the clothes getting too wrinkled waiting for us to unload it.
    - thatwebdude 9y ago
      ...my dryer simply doesn't go long enough to keep them wrinkle-free.
deleted 9y ago
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vinceguidry 9y ago

For household appliances to be used in this manner, they would have to be completely automated. Sure, I could choose to run my laundry cycle at 8pm rather than 5:30pm, but the convenience factor of doing it when I want to do it is going to trump the pennies they'd give me to wait, every single time. Now, if all I had to do was dump all my dirty laundry in a hamper, and it automatically sorts it and folds it after it's done washing, now that's something I don't care about anymore and can just let a program decide when it wants to accomplish each step.

ocschwar 9y ago
> Sure, I could choose to run my laundry cycle at 8pm rather than 5:30pm, but the convenience factor of doing it when I want to do it is going to trump the pennies they'd give me to wait, every single time. However, the heating element in your dryer doesn't have to be run like that. You start the dryer, and it starts tumbling your clothers with the motor, and blowing some air with the fan, but the heating element can turn on and off in coordination with the rest of your house, and you wouldn't even notice. Also, most of us run a load just before going to bed, and shuffle it to the dryer in the morning. Do you care if the washer takes a little while before starting up while you're sleeping? I sure don't.
- settsu 9y ago
  > Also, most of us run a load just before going to bed, and shuffle it to the dryer in the morning. Not if you care about the longevity of your clothing and mildew in your washer. I don't know anyone who does this routinely on purpose.
  - wernercd 9y ago
    How much mildew is going to build up if it starts an hour or two later? Or sits in washer for a few hours after finish? Waiting days? Sure... random-internet-answer(s) seem to hover around 24-48 hours before mildew becomes an issue... So, sitting over night and then maybe a few hours before the dryer starts (Assuming that, it too, would be on a timer) shouldn't be a major issue.

moron4hire 9y ago

> Each one of those things is inherently a form of energy storage, because you don't need any of those to start up or stop at the same milisecond where you flip the switch. You lost me. I don't understand how that connects.

halomru 9y ago
In a way a dishwasher is storing energy in the form of clean dishes. Now instead of storing electricity to run the dishwasher whenever, you simply run the dishwasher when there's an electricity surplus
- ocschwar 9y ago
  In particular, when the dishwasher's in the drying phase. Do you really care if the heating element turns off here and there at that time? Probably not.

nradov 9y ago

Running a clothes dryer unattended is not safe. Those appliances are among the more common causes of house fires. And as a practical matter, busy parents with small children can't defer running the washer and dryer. It needs to finish in time to fold and put away the clothes, and you often need to run multiple loads.

ocschwar 9y ago
> Running a clothes dryer unattended is not safe. Those appliances are among the more common causes of house fires. A smart-ified clothes dryer is more attended to than a conventional one. >And as a practical matter, busy parents with small children can't defer running the washer and dryer. It needs to finish in time to fold and put away the clothes, and you often need to run multiple loads I'm one of them. I can't always defer, true enough. But I can often enough.
- deadbunny 9y ago
  > smart-ified I don't care how smart your dryer is, if it catches on fire it's not going to do shit.
  - ajarmst 9y ago
    Well, if you equip it with a halon suppression system in a sealed and heavily sensored room, it might. Of course, now your dryer is your single most expensive possession by an order of magnitude. Which always seems to start being the problem when people propose "smart" solutions. "Well, first we need a class IV AI and on-demand local fusion energy, then everything gets easy..."
    - Dylan16807 9y ago
      I mean, you could just put in a few more heat sensors.
      - ajarmst 9y ago

oceanplexian 9y ago

Your house!? I think this misses the elephant in the room. Large industrial machinery. Data centers. Manufacturing. Electrified transportation. At the place I work, we use more electricity in a single, 19 inch high density server rack than your entire neighborhood. We have rooms full of batteries like the Tesla Powerwall and would be lucky if they could operate for 10 minutes.

rb808 9y ago
> Large industrial machinery. Data centers. Manufacturing The good thing is these loads are relatively constant and predictable. One reasons electricity is expensive is the peak loads are much higher than a regular day - you need a power station (or storage) on standby for that hot day when everyone suddenly runs their AC continuously all afternoon. >Electrified transportation This is different and a good opportunity that the article talks about. Esp a plugin hybrid could charge on windy sunny days and not charge in the peak times as above.
deleted 9y ago
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adrianN 9y ago
Huge loads like Aluminium smelters are already "smart" and cooperate with the electricity providers, so there is not as much left to gain there.
- askvictor 9y ago
  Yes and no; you can't just switch off an aluminium smelter with destroying it; it takes quite a bit of time to ramp it down. I think that for forecast high demand they shut down production in a planned way.
philipkglass 9y ago
In the United States, more electricity is used residentially than commercially or industrially (4.8, 4.6, and 3.2 quads respectively in 2016): https://flowcharts.llnl.gov/content/assets/images/energy/us/Energy_US_2016.png https://flowcharts.llnl.gov/content/assets/images/energy/us/...

xexers 9y ago

Don't forget "water heating". That could be done more dynamically than it is now... and water heating makes up 9% of household electricity usage: https://www.eia.gov/tools/faqs/faq.php?id=96&t=3 https://www.eia.gov/tools/faqs/faq.php?id=96&t=3

WalterBright 9y ago
True. A water heater tank can keep the water hot for a full day with no power. Even two days will still get you a warm shower. I discovered this during power failures :-)
jopsen 9y ago
It constantly surprises me how many places have electrical heating. I grew up in northern Europe where remotely heated water is the norm. https://en.wikipedia.org/wiki/District_heating https://en.wikipedia.org/wiki/District_heating In terms of efficiency, using excess heat, etc. electrical heating is utterly horrible.
ams6110 9y ago
Solar heated water is probably much more efficient than solar generated electricity.

agumonkey 9y ago

What about fridge heat harvesting btw ?

twothamendment 9y ago
I had a crazy idea to relocate the compressor and coil from my fridge to the mechanical room in the basement directly below it. It would cut down on noise and should make the fridge more efficient because it wouldn't be dumping its heat under itself. Once the heat is dumped in the mechanical room, a heat exchanger around the pipe to the hot water heater would have to help a bit. Even in the summer water out of the ground is pretty cold and anything to take the chill off would be a bonus.
- agumonkey 9y ago
  Basically what I thought. I googled and saw a few "fridge harvesting papers" I should read (or you ? .. ?) - http://www.irdindia.in/journal_ijmer/pdf/vol4_iss1/9.pdf - https://info.ornl.gov/sites/publications/files/pub31294.pdf - https://www.acoustics.asn.au/conference_proceedings/AAS2009/papers/p28.pdf

matt_heimer 9y ago

So you want priority queuing for power consumption. I understand it would be able to eliminate some spikes for my individual house but my overall usage doesn't go down. The article is really about the grid and not an individual house. If every house in my town had priority queuing would the hourly consumption really change? Maybe that last dryer or dishwasher load of the night could be time shifted but you can only delay refrigeration or clothes washing so long withing either spoilage or killing your throughput.

greglindahl 9y ago
Yes, smart grids can really change hourly consumption. As an example, imagine a world where 1/3 of the cars are electric, and they're long-range cars like the Bolt or Tesla, which only need to be charged every couple of days, not all of the time. A system that looks at the solar/wind forecast and charges your car at the right time can make a huge improvement to the grid on a time-scale of days.
- twothamendment 9y ago
  I still find "long-range" electric vehicles to be an oxymoron. A Bolt @ 75 mph can only make it 190 miles. I'm not sure that is enough to get me to a qualified mechanic and back and it sure doesn't compare to the nearly 500+ miles I get on fuel. I can't afford to drop $30,000 on a car that I can't take on a road trip. I think the progress made on electric cars is exciting to watch, but I have to laugh when they talk about "long-range". http://insideevs.com/instrumented-test-of-chevrolet-bolt-190-miles-of-range-at-steady-75-mph/ http://insideevs.com/instrumented-test-of-chevrolet-bolt-190...
  - greglindahl 9y ago
    You're getting off-topic, but, Tesla owners take road trips using the Supercharger network all of the time. Instead of focusing on your personal preferences, maybe you could also take a look at the actual behavior of early adopters?

twothamendment 9y ago

"Each one of those things is inherently a form of energy storage, because you don't need any of those to start up or stop at the same milisecond where you flip the switch." Using an appliance later is no more a form of energy storage than me "saving" air by holding my breath. Reduction in peak demand <> Storage. On a hot summer day when I'm cooking in the house, running a load of dishes and trying to cool the house to a reasonable temperature - all before the guests arrive - Should the A/C wait for the dishwasher, which waits for refrigerator, which waits for the oven? Not in my house. Storage - I'll gladly take some of that so my lighting and communication can be powered when the power is out. In that situation, the rest of those big loads can wait.

btowngar 9y ago
Load scheduling is precisely equivalent to energy storage. You store electrical energy with the intention of consuming it later. Load scheduling just makes this explicit. In fact one of the benefits of scheduling over storage is that there's no extra losses due to charging / discharging the battery.
- twothamendment 9y ago
  "One of the benefits of scheduling over storage is that there's no extra losses due to charging / discharging the battery." Loss - that should be one of the first clues that scheduling is not storage. Any electrical storage in my lifetime will have loss, I can accept that. I'll give you scheduling as storage when it comes to a freezer or hot water heater. Why? Electricity was converted to something that can be stored. There is loss - a clue to real storage taking place, not pretend scheduling "storage". If I heat a tank of hot water and want to shower an 3 hours later after I've turned off the power to my house I'll have a hot shower (in the dark). Try the same thing with an electric clothes dryer. Plan to run it in 3 hours and turn the power off and see how well it works. What? The dryer didn't store any electricity? Storage, by definition, means you have something. When it comes to the grid, storage and scheduling can both reduce peak demand, bug scheduling is far from storage.
- posterboy 9y ago

hwillis 9y ago

Back of the envelope math: Assuming a fridge has two cubic meters of air and twenty liters of water (the heat capacity of all the food and metal inside the fridge) and takes the temperature from 70 F to just above freezing (20 C difference), there's a heat storage of 472 watt-hours, or 1.6% of the average daily electricity consumption. A 100 gallon (380 liter) hot water heater that raises water from 50 F to 120 F (40 C) can store 17.6 kWh, or just under 60% of daily household power use. Of course this was gonna be huge, and its a good opportunity, since in the mornings a house will use 40-80 gallons with the showers. I'm not sure how much of that is actionable, though. The water would have to stay hot all night. The average newly built house in the US is 2600 sqft, which is 20,800 cubic feet with 8' ceilings. With a 45 F temperature change (25 C) the air in that alone is 5 kWh, which honestly surprised me with how big it is. You'll never want your house to be changing temperature that much during the day, of course. You'd get crazy condensation and whatnot. By the straight math this could cover 17% of daily usage- that could go up by several times due to the heat capacity of the objects and materials in the house, but down by 5 times since you wouldn't want your house changing that much in temperature. Water/heat capacity would be a pretty decent way to store a large amount of electrical load, but I think it's gonna struggle to catch on. In northerly climates you could combine the hot water and home heating, but those places will struggle much more to get cheap solar power, which is 2.5-3x more expensive in the winter. Meanwhile southern climates will have solar power at 70% the price of the rest of the country, and it tracks the summer power demand increase well- but it's way harder to store your energy in cold water. Other than that it makes sense: while you're at work, the system cools down a large insulated tank of water, which it then circulates to a heat exchanger right before you come home. You can't use it for hot water though, and it'll be a lot bigger and more expensive than an AC. Basically it would be good for load leveling, but not overnight storage or seasonal storage. There aren't many indications that load leveling is actually a real problem. It'll probably just be solved with a smarter grid.

deleted 9y ago
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wavegeek 9y ago
> By the straight math this could cover 17% of daily usage If you are heating from room temperature to RT+50C the actual energy extractable (as electricity) from that heat is only about 15% of what you put in https://en.wikipedia.org/wiki/Thermal_efficiency https://en.wikipedia.org/wiki/Thermal_efficiency. If you used the energy purely for heating you would in theory get it all back but the low temperature differential would mean in practical terms it would not work fast enough. You also need to factor in loss from conduction.

yourapostasy 9y ago

Once I started renting and eventually owning a house, it always drove me a little nutty to observe that many of those power consumers you cited are variations of a heat pump of one kind or another. I've always wanted to co-locate the heat output from the compressor of the A/C+refrigerator+chest freezer, dryer, and dishwasher into the same equipment space as my water heater, which uses a heat pump to extract that heat and cool the space at the same time. Any "overflow" heat I'd like to put into zeolite balls [1], and release back when needed for the washer, dryer and dishwasher to use. This is on top of the nuttiness I accrete after observing that foamed glass insulation that can put us up to terrific equivalent R-values (R-100+ pencils out if you intend the building structure to pass through several generations), and drop climate control operational energy costs 80-90% from current typical expenses, is a dead letter in the US residential market [2]. The amount of energy developed world practices and infrastructure throw away is mind boggling, once you view everything around you in energy flow terms. But like others are discussing in this thread, industrial and commercial energy use overshadows residential [3], over 60%. The low-hanging fruit sits there, because the ROI is typically faster or more bearable in those business-oriented contexts. I'll still pursue saving for and building a highly-insulated and -instrumented shell on my property once my house is paid off in a few years, just to scratch those nutty itches. [1] https://www.extremetech.com/extreme/130523-zeolite-thermal-storage-retains-heat-indefinitely-absorbs-four-times-more-heat-than-water https://www.extremetech.com/extreme/130523-zeolite-thermal-s... [2] http://www.greenbuildingadvisor.com/blogs/dept/green-building-news/foamglas-exits-us-residential-market http://www.greenbuildingadvisor.com/blogs/dept/green-buildin... [3] https://www.eia.gov/tools/faqs/faq.php?id=86&t=1 https://www.eia.gov/tools/faqs/faq.php?id=86&t=1

tekacs 9y ago
Speaking of everything being a heat pump, another interesting supplementary solution is https://en.m.wikipedia.org/wiki/New_York_City_steam_system https://en.m.wikipedia.org/wiki/New_York_City_steam_system
asdfgadsfgasfdg 9y ago
Be careful retrofitting insulation to a house. It can cause damp issues.

ouid 9y ago

The most inefficient time to run your AC is when it is hottest, aka the time that most people are running their ACs and are unlikely to stop running their ACs. Peak usage isn't as flexible as you seem to think. Also, hot days happen everywhere at once, so you can't even borrow power from other grids, because they are likely just as in need of power as you are.

WalterBright 9y ago
When it's hottest corresponds to when the solar panels work best, so there's that. Also, AC can be shifted. When power is cheap, use it to chill a tank of water or block of masonry, then use that coolness to reduce the AC load later. A tank of water can work just like a battery for HVAC.
- ouid 9y ago
  It's almost like you've forgotten the original argument.
- askvictor 9y ago
  Unfortunately, most solar panels point toward the equator for maximum overall power during the day. The highest demand for AC is in the afternoon; if panels faced West, they'd provide less overall power but more at peak times ( at least during summer)
- nkurz 9y ago
  When it's hottest corresponds to when the solar panels work best, so there's that. Sort of. Away from the equator, days are longer in the summer, so one gets more total energy per day during the season when it's hottest. But hour-by-hour, the peak temperature usually happens later in the day (mid-afternoon) than the potential peak solar production (noon). More pedantically, solar panels actually perform worse when they are hotter: https://www.thegreenage.co.uk/article/the-impact-of-temperature-on-solar-panels/ https://www.thegreenage.co.uk/article/the-impact-of-temperat.... The ideal for solar power would be full sun and frigid cold. In the extreme (Andean mountain versus Australian outback) this difference in efficiency might be as large as 50% (+25% for the cold, -25% for the hot). I agree with you that the "battery" doesn't necessarily need to store electricity, and that pre-cooling some large thermal mass might be better than a traditional battery.

FooHentai 9y ago

>with a little TCP/IP to coordinate activities around your house, your need for power storage declines considerably. There's been far lower-tech solutions for this stuff for a long time now: https://en.wikipedia.org/wiki/Load_management#Ripple_control https://en.wikipedia.org/wiki/Load_management#Ripple_control https://en.wikipedia.org/wiki/Radio_teleswitch https://en.wikipedia.org/wiki/Radio_teleswitch

deleted 9y ago

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jlg23 9y ago

> Each one of those things is inherently a form of energy storage Uhm. Maybe from a purely financial point of view. Physically they are energy consumers. They do not store energy in any sense that would be relevant here.

alacombe 9y ago

HVAC and refrigeration are critical. The first to heat your home when it's -30degC outside, and the second to preserve food.

hyperpallium 9y ago

Some, like Refrigeration, are also a form of storage. Your fridge stores coolness, and only runs when it gets too warm.