back to article Gov beta test for grid-friendly, carbon-saving smart fridges

Dynamic demand technology, in which domestic appliances adjust their drain on the national grid so as to smooth out collective spikes and dips, is to get a widespread UK trial next year. The Guardian, reporting on the new initiative from the Department of Energy and Climate Change, says that three thousand intelligent demand- …


This topic is closed for new posts.
  1. Anonymous Coward
    Paris Hilton

    Easy solution

    Just build more nuclear power. The one thing the French are doing right and other countries should copy.

  2. Steve

    Spike smoothing

    Rather than integrating fancy frequency measuring tech into every consumer device, why not fit a fairly chunky battery or ultra capacitor in every house. Fill it up when the grid is nominal, allow it to take some load as the grid is put under strain.

    I'm not talking about proper UPS, just something that could provide a couple of minutes worth of power to the household under normal drain, that should be enough to smooth the sharpest spikes.

    Pirate - spiky cutlasses

  3. GettinSadda

    Other appliances

    How about fitting this to some other appliances too?

    I have a 2kW electric heater in the room I am currently in (only option for this location!) and that should be able to adjust for short gaps quite nicely.

    Perhaps if I set the demand temperature to 21C {probably turning on at ~18C and off at ~24C) it could adjust this depending on grid-load (as measured by frequency) so that as the grid gets over-loaded it moves the range down a degree or two. If the grid has power to spare it could adjust up a little to compensate too. I very much doubt that most people would notice any of this happening.

    How many other devices could work like this?

  4. Jon G

    Scarp Eastenders and Corrie

    ...or just cancel Eastenders and Coronation Street - just think of the savings, as blokes across the country aren't kicked out into the spare room to use their games consoles whilst the missus watches the telly

  5. Filippo Silver badge

    A percentile here, a half-percentile there...

    ..add up to "not solving the problem". If the problem is becoming mostly independent from oil and/or bringing emissions to a point where CO2 in the atmosphere isn't increasing any more, then the only solution is nuclear power.

    Wind power, tidal, biodiesel, shutdown-instead-of-standby, banning patio heaters, even if cost wasn't an issue, would hardly make a dent in the bigger picture - and they have the detrimental effect of persuading the public that maybe, if we remember to turn off the lights and spend a bit on smart fridges, we can have sustainable energy without nuclear, and without stopping using cars and heating our homes.

    Which we can't. All this fiddling with tiny fractions of power consumption is just muddling the issue.

  6. Anonymous Coward

    Switched mode power supplies

    In days gone by, when the demand for electricity was close to the available capacity, the fix was to reduce the voltage, which worked fine in the short term - a few minutes - for resistive loads (heaters, some motors).

    These days, a lot of kit comes with switched mode power supplies of various kinds - electronics such as TVs, bigger stuff such as motors in factories.

    When you reduce the voltage, they don't reduce their power demand, they just take more current to get the same power. I've heard about this for ages but actually watched it with a meter the other day!

    A similar thing applies to kit with thermostats - reduce the volts, the heating output reduces, so to maintain the same temperature (of room, water, or whatever) the thermostat has to stay "on" for longer. The hourly energy input remains the same even though the voltage is lower.

    Remote control of domestic fridges, whilst interesting in principle, is practically pointless.

    To the poster who suggested domestic electrical energy storage: an interesting idea, especially if you have enough electric vehicles whose batteries can be used for that purpose.

    Anyway, there's trouble brewing ahead. Hence the need for a fire.

  7. davefb

    so standby is baad , mkay.

    but having all this electronics added to each appliance is okay?

    Oh but it's great , says the spokesperson for the company involved..

    This isn't really carbon saving is it ? Since the overall consumption would stay the same , but add the consumption for the detection hardware??

  8. Paul

    WAX blocks

    OK, this is from memory of an article a while back so please excuse any errors.

    A company that manufactures wax products is making a mint producing wax blocks to fit around the temperature sensor of commercial fridges. It smooths out the rapid variations during normal use. By reducing the high number of short active periods an overall saving is achieved.

    Could this method be applied to domestic fridges? I have a few candles I can melt down so maybe I will experiment.

  9. Anonymous Coward
    Anonymous Coward

    Think big...

    Lay a cable between Britain and Iceland and tap into some of their enormous untapped hydroelectric potential. We get a huge amount of clean electricity, they get lots of hard currency and a diversified economy.

  10. Rob
    Black Helicopters

    Hardly selling it to the consumer...

    ... we've just been given news of reduction in VAT which could save consumers anything up to 3p if they are buying a Mars bar, even Joe Public saw through this as being completely useless. Saving something like a £10 on your yearly leccy bill still isn't going to impress the average Joe.

    Yet again it seems another issue dodged by the governement and dumped on the consumers door because nobody in central gov seems to have a clue about anything.

    At what point will Gov actually think seriously about alternative power sources, as in actually supporting research in that area. This countries R&D has fallen through the floor and they wonder why science and technology in schools isn't as popular as it used to be, of course nothing to do with funding sources drying up due to central gov bailing out bolovian marching powder snorters from the city who have dropped us in a recession.

    Viva la revolution!

  11. Anonymous Coward
    Anonymous Coward

    Food safety?

    With this comes a risk of fridges drifting to higher temperatures than normal:-

    Note the very small temperature discrepancy.

    Might be better to run up a big flywheel on the compressor overnight when you get reduced prices or just batteries or those giant cap's.


    You would hope that a micro-controller operated fridge has better temperature control than a wax block stuck on a thermistor.

  12. dodge

    Are we not creating a dangerous resonant system?

    Just tossing this on the plate to see if anyone pours mayonnaise on it, but the beauty of the current system is its randomness... you may get some clustering (gaussian?), but generally one assumes fridges will turn on in a pretty random distribution.

    But now you fit a whole bunch of devices with electrickery that essentially links them to a system, would this not start to bring them into a synchronisation with each other, possibly creating an avalanche of fridge power-suck? All the fridges in Blighty all stay off because they detect grid strain, and when it relieves they go "phew" and turn on. Goodbye handy random distribution. Fair enough in the evening when grid is under least strain ... but that's when you don't really care. And its during the heat of the day that they'll be turning on and off more often.

  13. Anonymous Coward
    Anonymous Coward

    Some much simpler ideas...

    Just turn the fridge down a notch. Also, loose weight and maintain fridge temperature by not opening it so often.

    Same with heating. Turn down the heating by 1 or 2 degrees. The net effect over a millions of homes must make a difference.

    Some extreme ideas -

    Ban the sale of tea, coffee, hot chocolate, Ovaltine and Horlicks- no need then for several million kettles to switch on after Eastenders.

    Ban the sale of large fridges, especially those big American style monsters - if most of the food stored in them is thrown away anyway, by keeping the sizes down, fridges will only hold what people need, not what they think they need.

  14. Anonymous Coward

    Dynamic demand technology on refrigerators

    Here in the States, we call those "thermostats". They work on furnaces as well.

  15. Ian Ferguson
    Dead Vulture

    Funnily enough

    Not all of us are selfish enough to ONLY think of the financial cost or advantage to ourselves. If the appliances I can buy in the future help reduce the country's power consumption, at no noticable cost to myself, I'd be happy to choose those appliances.

    I think this is a great idea, and don't see any particular reason for knocking it. No, it's not going to solve global warming (debatable I know) or our dependancy on fossil fuels (no debatable), but as you well know, there isn't a golden solution to it all - it's many little savings and improvements in efficiency around the place that will matter.

    And as for most consumption being industrial - in that case, apply this technology to industrial machines as well as consumer machines. Be positive for a change!

  16. Chris

    cable to iceland

    im no physicist but i would imagine the loss of power due to resistance in the cable will not make it worthwhile. He we had superconducting cables, them maybe.

  17. Dave
    Paris Hilton

    Isn't this an old idea

    Remember "Economy 7" using cheap off peak 'leccy for high power appliances like water heaters and storeage heaters, to mop up the spare grid capacity at night

  18. david wilson

    £2 per bill

    Would seem to make sense given the figures, if the bills are quarterly ones.

  19. Richard Porter

    Wouldn't it be better..

    to have a water heat exchanger at the back of the fridge and use the extracted heat to pre-heat the hot water supply tank insted of releasing it back into the kitchen? You would only need a couple of 15mm pipes from the kitchen to the loft or wherever the tank is located.Such a system would actually reduce the energy consumed by the hot water system.

  20. Richard

    @Think big...

    Would be nice ... they could pay back all the hundreds of millions they owe us 8-)

  21. Dan Paul
    Thumb Up

    Building Control Systems are one answer

    I work in the Building Automation business in the USA and these systems perform load shedding for commercial & institutional buildings on demand.

    If there is a high demand for electricity, the power companies can tell their customers to go into load shedding mode and the customer uses their building automation system to reduce lighting, heating and air conditioning loads. When the power shortage is over, the equipment is brought back online in staggered sequence to prevent usage spikes.

    Of course the building has to be designed to use these Building Automation Systems properly but the fact remains that the technology is already here, it's not being used to the fullest potential.

    In California, they even have a pilot project that allows a homeowners thermostat to be remotely controlled by the power company in the case of power shortages.

    So let me know how you feel about the power company controlling your personal comfort or even your refrigerator. I'm sure you'll have something to say.

  22. Anonymous Coward

    Uses same energy, needs maybe 1GW less capacity????

    With the greatest possible respect to Ian... the technique being discussed does NOT noticeably decrease the energy consumption in this picture. Anybody's fridge will still use roughly the same number of kilowatt-hours (aka "units of electricity") per day, per year, etc. What this technique does do is allow some control over the timing of the demand from appliances such as freezers, heaters ("furnaces"), etc, where the thermal inertia means that there won't be too much effect if the motor has to stay off for an extra few minutes. But the amount of generating capacity that we're saving, at least with fridges and freezers, is really quite small. If it was immersion heaters, maybe it would be different? Maybe?

    Do some sums, based on facts not hype. Fact: a decent modern domestic freezer typically uses very roughly 200 kWh per year. Call it 0.5kWh per day. The actual power consumption is a few hundred watts when operating, but most of the time they sit idle; to make 0.5kWh a day it could be say 500 watts for 1 hour a day. So at any given time, the chances of any given freezer motor running are roughly 5% (1/24). If there are 20 million or so freezers in homes in the UK, if you could switch them all off for a while, you might actually switch off 5% of 20 million as the rest weren't running anyway. So 1 million freezers at 500W each get switched off. That's 500MW (0.5GW) of generating capacity we don't need to build, or can leave idle. Decent power stations are usually a few GW.

    So is this really a worthwhile saving? It might be, e.g. if we're looking at just South East England, and the London Olympics need more power than can profitably be delivered to the South East, but in general 0.5GW across the UK is not a huge deal. The UK's actual electricity demand in the last 24 hours varied between roughly 30GW and 60GW [1].

    The Yanks talked about this kind of thing a year or two back, when the Gubernator wanted Californians aircon boxes (big things, they are) to be remote controllable by the electricity supply folks. That kind of thing makes a worthwhile difference to electricity demand out there.

    But fridges and freezers? They're having a laugh.


  23. Anonymous Coward


    What iceland has is more geothermal than hydroelectric, but I take your point.

    If they played their cards right maybe they actually *could* export some of their energy. Maybe not via undersea cable, maybe by boat as liquid hydrogen? After all, now that North Sea Gas has practically run out, we're already importing liquefied methane (LNG) from our friends in Libya and the like. Doing it with liquid hydrogen instead wouldn't be that much of a problem in transport terms, you just need to choose sensible end users.

    Using natural gas to generate electricity was always a daft waste of a limited and valuable resource, but market forces can't be expected to reflect that.

    So, convert a few of today's big gas-based power stations (and maybe a few CCGT ones too) to run on imported hydrogen instead, and the natural gas it frees up can be used for more valuable things (maybe domestic and commercial heating, cooking, etc?).

    You could do the same with hydrogen generated from solar electricity in Africa. We're already importing LNG from there; it won't last long, but solar power (and geothermal in Iceland) will hopefully be around for a while.

  24. Anonymous Coward

    Make it pay

    To even out spikes, the obvious thing to do from an economic perspective would be to charge more for electricity when it is in demand. Given that freezers can manage it, it's obviously technically possible - it would 'just' need ~30 million meters to be replaced. And if the law is being set up to require the grid to take all micro-generator output, maybe the two could be done at once.

  25. Anonymous Coward
    Thumb Down

    give me a break

    (1) do you REALLY, REALLY think your 'leccy bill will be going down and that you will ever live to see it? everybody out there raise a hand if you seriously believe this.

    (2) any idea what this will cost for a new fridge and what will happen to the one you have now that's perfectly good? who is going to pay to put enough of these in place to make it worth while. I'll wait.... that's what I thought.

    (3) and idea how much more effective it would be for big business to implement the type of power savings they are needing to make this workable? Think they'll get some nice tax write-off to cover it? Yup, thought so.

    (4) any idea how long this new "circuitry" will last in the new fridge? how long has it been tested in real usage with repeated signaling sent to it to control anything?

    You'll gain more savings replacing incandescent bulbs with CFLs; and they have their own problems.

  26. Anonymous Coward
    Anonymous Coward

    @Dave : Economy 7

    I'm still on it the entire flat is electric.

    In fact, if everyone were put on it then the national energy consumption would massively drop because no-one would be able to have warm showers or heat their house properly.

    I think they should dedicate a GCSE to operating the bloody heaters as well, they have an incredibly mystic set of controls and obviously no-one has ever seen a manual for the damn things.

    If you really want to save the planet ditch the gas. ;)

    Perhaps the biggest effect on energy for fridges would be to have inner doors so only the compartment that has the milk in gets opened. Wouldn't make a very nice fridge of course.

  27. Christian Berger

    Saves power and nice idea

    First of all, currently the grid actually has to _waste_ power transforming it into heat in order to cope with sudden drops in supply. The AC system forces all generators to run synchroniously. So if the demand suddenly drops, the turbines would move more easily and you'd have to adjust the steam. This can, unfortunately not be done quickly, especially not with nuclear power plants. If you could shape the demand, you could suddenly also use more regenerative energy like wind or solar. Simply put, you would tell your fridge to cool down your stuff during the day or when it's windy.

    What I like especially is the simple idea to do it over the mains frequency. It's simple and elegant.

  28. Anonymous Coward
    Anonymous Coward

    ...frequency... Huh?

    The article's credibility departed at about the point where it said "As any fule kno, the UK national grid's frequency rises and falls from its base level of fifty Hertz in response to demand variations against supply. As more electric power is used, the frequency changes."

    Er, no. Clearly the author doesn't grasp the basics about the fluctuating grid demand. Frequency remains pretty much constant, precisely synchronised as it is to all the huge spinning things that generate electricity.

    Demand fluctuations more typically cause the voltage to drop. Shedding load can be useful as a way of avoiding firing up some extra generating capacity. Typically this is the most expensive to run, so it tends to be kept as a last resort.

    Renewable energy such as wind tends to be less predictable than other generators, so when the wind drops, it is helpful to be able to shed load quickly rather than turn on other generators.

    Shedding loads from fridges may be temporarily helpful, but, as AC at 23.02 has estimated, is probably insignificant. Turning off immersion heaters, electric heating and large industrial loads could make a much greater contribution. This is already widely done. The technology to do it has been available for at least twenty years.

    While demand side management could help alleviate short-term power demand and supply fluctuations, and solve some of the problems that renewable generation causes, it is not a panacea to our energy needs.

  29. Anonymous Coward

    Interesting idea, and it's been bandied around for a while

    ... but you're going to need a large number of 'dynamic demand' applicances out there in order to make any measureable difference. Unless carefully implemented, there must be a risk that a system with many 'dynamic demand' appliances coudl become unstable.

    An obvious possible issue is that if (say) at 6pm the grid is slightly short of power, the fridge would like to run for a few minutes to cool down, but decides to 'hold out' to help the grid. By 6.10, the fridge is getting more desperate for power, but (say) in that time the grid has also got an even worse energy balence. Come 6.20, the fridge has reached 'critical', and fires up anyway (along with all the others in the land which have been holding-out) ... despite the fact that the load balence on the grid is now substantially more overloaded than it was at 6pm.

    Even if the applicance can monitor the trend in frequency, it's still got little capability to forecast whether the grid-load-balence situation will be better or worse in 10-minutes time than it is now.

    Very large industrial users of electricity get a special discount for having a deal which allows their power to be abruptly cut at no-notice to cope with demand-surges.

    I guess the idea of dynamic demand is really to help cope with demand surges of 5 minutes or less, rather than longer term minor under-supply.

    For anyone who's interested: real-time grid information is available here:

    (it has had phases of being down/flaky, so check if it makes sense)

  30. Clark Campbell
    Paris Hilton

    Ban shops - simple

    Certain MEPs and MPs have proposed banning patio heaters as they appear to be decadent eco-destroyers.

    Personally, I think the gigawatts that are used to power the country's millions of fashion store spotlights - and airco to keep the staff and punters from frying - are decadent eco-destroyers.

    Ban H&M and their ilk, that's wot I say.

    As a geek, if I can't find what I'm looking for by rummaging around in the dark in Matalan or the Army Surplus store - I ain't interested.

    Paris - cos she proves the point that "less is more"

  31. Anonymous Coward

    Brushless motors

    STMicroelectronics make microcontrollers that control brushless AC and DC motors (ST9xx and ST7xx). The idea is that the fridge motor runs all the time (no brushes to wear out as in conventional motors) spinning faster and slower as demand requires. Ally this to proper 3 term temperature control and the sudden spikes would largely be ironed out. (fridge temperature rises quicker if there is no food in it creating the random speedup time). It is programmable (8 bit just like the old IBM PC) so there is the IT angle.

    What is wrong with hydroelectric generation, it's always bloody raining round here in Wales and a dam on the river behind my house would have stopped the two and a half feet of water that came rushing into my living room a month ago.

    Can I have a new fridge please as mine is now broken due to the above mentioned flood

    Mine's the one dripping wet and covered in mud

  32. Anonymous Coward
    Anonymous Coward

    Re: ...frequency... correction

    Ooops. No, I was wrong. Should have checked! Grid frequency does change a bit in response to load. According to National Grid, who would know:

    “System frequency is a continuously changing variable that is determined and controlled by the second-by-second (real time) balance between system demand and total generation. If demand is greater than generation, the frequency falls while if generation is greater than demand, the frequency rises.”

    There’s a real-time graph of the variation over the last hour at

    Lately, it’s peaked at 50.18Hz and gone down to 49.95Hz.

    So there’s scope for fridges and many other devices to detect this variation and behave in a suitable pre-programmed way to shed load as necessary. Provided they have properly thought out algorithms and some randomisation, it should be possible to avoid inducing chaotic behaviour in the grid that some have suggested.

  33. Anonymous Coward

    @ac 15:54

    Sir, I salute you. Not many people would admit their error so graciously. What a fine example to set. I'd intended to politely correct it earlier with a link to the Gridco page as evidence, but I've been otherwise occupied.

    So, now you're convinced the theory works, all we need to do is make it happen for real, perhaps using something a bit more substantial than a tiny proportion of devices which are themselves a tiny proportion of electricity demand. Maybe we could have LCD+plasma TVs switch themselves off during the commercial breaks, to compensate for the kettles which get switched on during commercial breaks? Ah, OK, never mind, I forgot that...

    Earlier today when I tried the Gridco live chart, it was timing out. I wonder if they've been slightly slashdotted today?

  34. Anonymous Coward
    Anonymous Coward

    Re: Interesting idea, and it's been bandied around for a while

    There are plenty of ways to control loads, and within certain obvious constraints (such as not suddenly turning off lights, life support systems, or Eastenders), it is a useful thing to be able to do.

    An alternative system is the Radio Teleswitch, lucidly described at This uses the 198kHz BBC Radio Four transmission system to signal to local units.

    The principles have been around a long while. Radio Teleswitch was first considered in 1964 and has been available since 1984. There are thought to be in excess of 3 million RTS equipped meters in the field.

    Another approach is to use two-way communicating meters (so-called smart meters), but this needs some sort of communications system back to the control centre. All the major meter makers offer them, e.g. Itron OpenWay, Sensus FlexNet, Cellnet Utilinet.

    There’s a lot going on in the field. The IEA Demand-Side Management Programme ( shows the scope of the ideas being developed.

    But it only helps with short-term power and grid management, particularly that which comes from unpredictable sources such as wind; it doesn’t provide for the basic energy needs.

This topic is closed for new posts.

Other stories you might like