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Power Science

Smart Power 41

Posted by samzenpus from the I-can-feel-the-whole-house dept.
ajnsue writes "How would you like to control your homes power consumption at the level of the appliance - About 300 Washington State and Oregon Power users are now testing software and devices that allow them to actively control their household power consumption based on the price of power. From the article... "...(Using)real-time price information (provided) through a broadband Internet connection and automated equipment that will adjust energy use based on price. In addition, some customers will have computer chips embedded in their dryers and water heaters that can sense when the power transmission system is under stress and automatically turn off certain functions briefly until the grid can be stabilized by power operators." This technology also provides beneift to the provider network "...The Grid Friendly TM Appliance Controller chip could help prevent widespread power outages by turning off certain parts of an appliance when it senses instability in the grid - something that happens about once a day on average. Shutting down the heating element for a few minutes, while the drum continues to tumble, would likely go unnoticed by the homeowner but drastically reduces power demand within the home...""
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  • It's about as unlikely that a dryer would be affected by a momentarily jittery power signal as an elephant would notice stepping on a cracked peanut shell.

    As for dryers automatically shutting down the heating element, it makes sense to do so to conserve energy anyway. You wouldn't leave your car engine running all night just to keep the seats warm for when you wake up the next day.
    • >> It's about as unlikely that a dryer would be affected by a momentarily jittery power signal as an elephant would notice stepping on a cracked peanut shell.

      The dryer may not care but a strained power grid suddenly having significant load reduced as the modified appliances reduce their power usage would.

      >> As for dryers automatically shutting down the heating element, it makes sense to do so to conserve energy anyway. You wouldn't leave your car engine running all night just to keep the seats w
    • It's about as unlikely that a dryer would be affected by a momentarily jittery power signal as an elephant would notice stepping on a cracked peanut shell.


      Well, considering that the elephant's feet are extremely sensitive sensory organs, I *think* it would notice... ;-P

    • Comment removed (Score:4, Funny)

      by account_deleted ( 4530225 ) on Thursday January 12, 2006 @09:10AM (#14453655)
      Comment removed based on user account deletion

    • Re:Excess power usage (Score:3, Insightful)

      by CMiYC ( 6473 )
      As for dryers automatically shutting down the heating element, it makes sense to do so to conserve energy anyway

      The example of the dryer shutting down isn't to conserve energy. The example given is for when the power grid is un-stable because of execessive usage. If enough appliances suspend their power activities for a few minutes or have the ability to coordinate their usage, then the power-grid will remain stable.
    • Some folks at work do insist on leaving their space heaters on all weekend to ensure that they do not face fifteen minutes of chilly discomfort on Monday morning. I took this up with their department's supervisor, only to discover that it was her idea.

      So your second analogy might be bad for a reason other than you thought. Good effort, though. :-)
  • This technology also provides beneift to the provider network

    Where was the bit about how it benefits the consumer...? While I'm all for energy conservation, this sounds like the thin end of a 'lets ration your electricity' wedge.

    • Re:"Benefit"? (Score:3, Insightful)

      by Tx ( 96709 )
      Well, cost, according to TFA. It's not strictly rationing, since the consumers choose when to curtail their energy use. But as usual I suspect the energy companies will benefit more than the consumers, and since they control the other important parameter, energy price, I guess it could indeed be seen as a sort of rationing.

    • Re:"Benefit"? (Score:3, Informative)

      by Capt'n Hector ( 650760 )
      Where was the bit about how it benefits the consumer...?

      Less power outages. People in California know what I'm talking about...

      • Re:"Benefit"? (Score:3, Interesting)

        by skinfitz ( 564041 )
        As do I - was not pleasant being stuck in a house in Highland Park in July last year during power outage lasting a few hours in 90+ degree heat.

  • Dynamic Demand (Score:5, Interesting)

    by bjpirt ( 251795 ) on Thursday January 12, 2006 @06:02AM (#14452785)
    A friend of mine is working on a similar system here in the UK. Have a look at his website [dynamicdemand.co.uk] for more information.

    It is a really elegant solution to the problem of grid instability. I love the idea that by measuring the frequency of the grid you can tell whether there is a surplus or deficit of power and then decide to either cool the fridge further or wait until there is a surplus (or until the temperature drops to it's lowest limit). This way you could treat all of the fridges in the country as a massive battery, using the surplus power so they don't need it when there is a deficit.

    One of the big benefits is to make it easier for energy sources with an unpredictable output to be integrated into the grid, such as renewables. It also avoids having to turn on extra turbines when there is a grid emergency, saving lots of CO2.
    • I love the idea that by measuring the frequency of the grid you can tell whether there is a surplus or deficit of power and ...

      I don't think they (or at least should) use the frequency to measure the load. You can trust the grid to supply an average frequency as specified (50/60 Hz).
      Appliances are more resistant to variations in power (read: voltage) than in current or frequencies and the power supply reflects this; the supply voltage in the outlets are usually "far off" the specified value (110/230 V
      • I don't think they (or at least should) use the frequency to measure the load. You can trust the grid to supply an average frequency as specified (50/60 Hz).

        On the contrary, frequency is an excellent indicator of power system health. Proportioning the load to observed frequency is a simple and potenially very effective method of improving power system stability.

        Appliances aren't that picky about frequency (with the exception of synchronous motors used for tape machines and turntables) - I've seen motors

    • An interesting idea, but wouldn't it be better to just have a home battery backup system, like your computer does? Not something that'll let you live off grid, just something that'll keep your home going for 30-60 minutes, on average. Then you don't have to overcool your fridge before the grid has issues and let it warm up when there are issues. Same goes for heating (electric dryers, stoves, etc) and lights.

      One of these proposed sensors, several car batteries (or similar) and an inverter. Charge the batter

    • Re:Dynamic Demand (Score:3, Interesting)

      by radtea ( 464814 )

      I think this is a great idea, but wonder about some of the implementation details. In particular, this implicitly couples all the homes using the load-leveling technology. That creates the possibility for feedback.

      A simple scenario goes like this: demand on a given sub-grid is high due to a particular industrial load, say. All the homes in the area dutifully stop running their fridges and moderate their air-conditioning (by far the two biggest cyclic loads). The industrial user goes off-line, and all t
    • That web site has a cool power meter [dynamicdemand.co.uk], which gives me an interesting idea. If PCs could receive dynamic power data like this, which was reliable (and they claim this meter isn't calibrated), they could be set to adjust their screen blanking interval accordingly, which would save a great deal of power from CRT monitors.

      The user could set a minimum, average, and maximum screen-blanking interval, and an extreme power emergency could force monitors on, or maybe even off.

  • Off-peak meter (Score:2, Insightful)

    by tdemark ( 512406 )
    Doesn't all this technology re-invent what we already have via the "off-peak meter"?

    When our house used electric drying, cooking, and water heating, we had a secondary meter on the outside of the house. This meter powered a separate panel to which the above devices were connected to and was scheduled to be turned off from Noon to 7 PM every day and could be turned off at any other time at the POCO's discretion.

    In exchange for this, power from that meter was about 25% the cost of power from our main meter.

    Do

    • Re:Off-peak meter (Score:4, Interesting)

      by warpSpeed ( 67927 ) <slashdot@fredcom.com> on Thursday January 12, 2006 @10:02AM (#14454169) Homepage Journal
      Doesn't all this technology re-invent what we already have via the "off-peak meter"?

      Two point to this. First the power company controls this, thus elimnating your ability to pay more to get power when you need it.

      And second, with the individual appliances doing the work you get more granular contol over your power consumption.

      I think allowing your appliances to be programmed by you is a good start to the power problems we face. If this comes as a standard option in most appliances, much like the "green energy approved" appliacnes more people will start to use it. People savvy enough to take advantage of it will (in theory) save money. The Power companies will save money, and there will be less demand for power during peak usage periods, thus less outages.

      The 2nd power meter is a good theory, but the costs to deploy it in a wide spread fasion are too large. Rewiring and adding a second meter is cost prohibative in general for most home owners. Having all your appliances manage your power consumption for you is a much better plan. Your going to have to replace your appliances at some point, but you do not have to install a whole new power system in your house.

      • In Belgium we have a similar but better system :)

        You can have a dual meter in your house, one for electricity at night and the other for your usage during the day. It's one box with 2 meters. Hours can depend from town to town, but usually 10pm - 6am is 'night tarriff'.

        In the fusebox there's a switch installed which gets automatically triggered by the power company. To that you can connect the parts of your house which get activated at night (water heater on electricity in my case). The power company contro
        • Any system the encourages the easy savings of energy is good. The only nit I have to pick about this system is why would the general public sign up for something that if you are caught in a bind and need to use power during peak periods you pay a preimium over what the general public would pay. Why risk it?

          I guess if you can setup your house appliabces to work on a schedule and the savings was there (and it would have to be big) it would be worth it.

          In the ideal world you want to encourage everyone to

          • Over here (Finland) the dual rate thing goes like this: For those who have a dual-rate contract, all power comes in through one meter, which has two counters. It switches between them by control signals from the grid. One counter is for the daytime rate and the other one is for the nighttime rate (obviously). Any electricity consumed is tallied to the meter currently in use. Therefore, it is economical to run things like water heaters and washing machines at night, but nothing prevents them from being used
  • I do hope that the devices are programmed *carefully*. Somehow I feel trepidation about devices that add or shed significant load (driers? air conditioners? water heaters?) based not on local conditions (in a thermostat or such) but responding to less local conditions on the power grid...all at once.

    It's not hard to see how having a large number of installed devices all running the same or similar program could cause *instability*.

    Think of programmed trades on the stock market, for example.
    • Two things that together determine the stability of a feedback control system are the loop gain and the loop phase delay. High gain and a long delay in the loop make for a very jittery system and one that's easily driven into oscillation. In the power control system described, adding more and more 'smart' devices would progressively increase the gain, while the delay would be somewhat unpredictable, since it would depend on the speed of an appliance's Internet connection and the speed at which the power uti
      • it would depend on the speed of an appliance's Internet connection and the speed at which the power utility updated its energy forecast

        What Internet? What forecast? From the other comments, it seems like the devices look at the power signal itself to determine whether the grid is in trouble or not.
        • The article summary mentioned, among other things, the appliances getting price-of-power and system load information over a broadband Internet connection. So that's where my Internet reference came from. Having the devices use local frequency change information is possible only if they have access to a long-term-stable frequency reference, and even then their reaction time and their local environment would influence the stability of the control loop.
          • The long term stability of the frequency reference is not critical - something on the order of 100 ppm should work nicely (my Timex watch does better than 10 ppm). A simple device that drops the load when the local frequency dips and picks up when the frequency rises would do wonders for improving grid stability as it acts to damp out the oscillations in the power system (think huge weights connected by springs - the frequency sensitive load acts as friction).

            Another way to describe what's being done is lo

  • There are lots of hair-brained ideas to merge the Internet with Fridges and toasters, but when it comes to energy conservation, this is where the idea makes sense. It's not an outrageous idea at all.

    First, by having each appliance monitor its energy consumption, this will make consumers aware of just how much energy respective appliances are using. Outside the Geek and Nerd community, many people are simply not aware that running an oven or dryer for hours at requires a lot of energy and can cost a lot of

  • Limited usefulness (Score:4, Interesting)

    by blueZ3 ( 744446 ) on Thursday January 12, 2006 @11:20AM (#14454924) Homepage
    I can only think of one appliance that runs without intervention--that's the refrigerator. Everything else in my house that requires significant electricity is run on demand. I'm not sure I see how helpful this is going to be overall.

    Take this scenario: I am running a load of laundry through the clothes dryer and it's about 1/2-way dry. The dryer "senses" that the grid is under stress and turns off the heating element, but the drum continues to spin. The grid stays under stress for 30 minutes, then things return to normal. The dryer senses that the grid is normal and turns the heating element back on. The element must return to its heated state and dry the clothes the rest of the way. To me, this sounds like a recipe for selling more power, not less.

    In any event, having worked for a company that provided metering services to electric utilities, I can say that "grid stress" is almost certainly not the real reason behind a push for this technology. The idea of "grid stress" makes it sound like the transmission mechanisms are under stress. But in reality, the problem is peak power generataion. During peak power usage, utilities rely on "peaker" power generation (sometimes small diesel plants) which frequently cost an order of magnitude more to operate than regular power generation. For instance, if it costs the utility $0.07 KWH to produce power, peaker power may cost $0.70 per KWH. However, most utilities are not set up to charge based on time of consumption, so the flat rate the PUC allows them to charge (say $10.10 per KWH) means that generating this extra power is a loss for them. So anything the utility can do to reduce spikes and eliminate the need for this type of generation is going to save them big money.

    • I can only think of one appliance that runs without intervention--that's the refrigerator. Everything else in my house that requires significant electricity is run on demand. I'm not sure I see how helpful this is going to be overall.

      I don't know if you've looked at the 'dynamic demand' link above but basically it talks about reducing power consumption to deal with short-term grid fluctuations, i.e. people boiling the kettle during TV comercial breaks. At the moment short fluctuations are dealt with by havi

  • Smart Power Usage (Offtopic) (Score:4, Interesting)

    by OzPeter ( 195038 ) on Thursday January 12, 2006 @12:01PM (#14455366)
    [rant-ish]
    Its interesting that the article summary mentions the dryer as one appliance to turn off when the power grid gets stressed, as I feel that the dryer is the one thing for which there is a perfectly good solar equivelent .. its called "the Sun".

    Growing up in Australia, pretty well every house had a Hills Hoist [ozbird.com] in the backyard, and clothes were dryed by the power of the Sun. It was only during the most shitty weather that you couldn't get the 1/2 day needed to dry your load of clothes.

    Now fast forward to me living in the US. I find that 2 story houses are being built with the Laundry room on the upper floor as it minimises the transport of clothes to/from the bedrooms/bathrooms where they are most likely to be removed/stored, so you are being coerced to use the power hungry dryer over the use of a more environment friendly method. But what astounds me more is that many communities have laws restricting placing any sort of clothes line out in the backyard. Thus on a day like today, when the sun is streaming in my window, I am going to have to use the dryer to dry the clothes I will be washing (And yes I do realise that I could string my clothes out inside the house .. but dripping water doesn't do carpet any good either)

    It just seeems crazy to me that arbitrary asthetic restrictions are forcing people to use more energy, and that high tech solutions are being enacted to reduce peak energy usage. What is being proposed is not really energy reduction or energy effieciency, but rather shifting the production of energy to time periods when it won't be noticed. To me this is really sweeping the energy production limitations under the carpet while allowing society to keep increasing average usage. In the long term its nuts to do so.

    Why are we headed in this direction? Where are the programs for reducing energy consumption? Or are the leaders who dictate energy policy playing Nero while Rome is starting to smoulder in the background? I wish I knew the answer to these questions.

    As an example of energy policy, there is the current US issue of drilling in the arctic wilderness (Note that I am not Bush bashing, just that he is currently the leader and this is a current issue .. I am sure other leaders had their own examples) A few years ago I saw the projected energy output from the potential arctic park drilling. Over the course of its lifetime, it amounted to at most 10% of the total US energy consumption at any one time, while the energy usage growth over that same period was huge, easily more than 10%. It would seem that if you could enforce more energy effieciency, then you wouldn't have to be scrapping around in contreversal places looking for more.

    As a final stat, it is pretty common knowledge that in rough terms, the US has 5% of the worlds population, but uses 20% of its energy. I can't see this as being sustainable in the long term, as what happens when the other 95% of the worlds peoples want *their* 20% of the worlds energy? Somewhere it is all going to end in tears for some people.

    [/rant-ish]
  • While I'm all for energy conservation, especially when it comes to completely unneccessary little things like the blinking LED on your VCR, I see an unintended consequence of this being that utility companies have even less incentive to upgrade the nortoriously outdated power distribution system (e.g., the great blackout of 2003 http://www.cnn.com/2003/US/08/14/power.outage/ [cnn.com]). Kind of like how faster processors and more RAM means software makers have less incentive to remove bloat and memory leaks from thei

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