Time of Use Tariff Saves Me Money

  • wizzo227's Avatar
    Level 22
    At risk of somebody else mentioning the name of somebody else's trademark price-every-half-hour smart meter electricity tariff, has anyone else noticed that all the half-hour prices overnight from around 23:00 BST to 07:00 BST tonight are nil or negative electricity pricing ? As in between 2p and -2p /kWh electricity for those on the price-every-half-hour deal.

    I won't be a complete pig over this; I won't switch on every fan heater I've got, but were I to do so, that would spend less than £1 to severely overheat this small well-insulated ordinary house.

    What I will do is switch on the small wall-mounted heat pump to draw 0.7kW and deliver about 2kW of heat, both for half of the time. Expected cost is much less than £0.10 for expected gain of several kWh of heat to one room overnight.

    The cause of this overnight electricity glut is likely to be a lot more wind than average, so those who can use it should.

    This kind of bargain does not often happen. This time-of-use pricing deal won't suit everyone because it is extra-expensive at after-school time 4pm-7pm, recently going over 40p/kWh. I just don't use much at those times, and preferentially use the cooker and heavy appliances at less expensive times. Daytime <20p/kWh and occasionally much cheaper is available to those who bother to use it.

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    Last edited by wizzo227; 12-10-24 at 19:26.
  • 16 Replies

  • Andy65's Avatar
    Level 47
    At 3am 57.7% was wind generated @wizzo227. TOU tariffs are good for those that can, and want to manage their usage. I know a fair few people who just wouldn't be interested and would rather pay a more expensive flat rate for convenience.

    There's quite a lot on YouTube that have seemingly turned managing their TOU/Solar/EV into a serious hobby. Those on flat rates can get surprising results just by switching stuff off and managing their appliances a bit better.
  • meldrewreborn's Avatar
    Level 91
    I don’t yet have a smart meter but I’m sceptical that the UK population will take to TOU tariffs in great numbers. If they require people to continually monitor their usage and be reactive to both low and high prices, I think that most people will lose interest very quickly.

    I can well imagine that offers to reward cutting consumption at peak times might be well received, but that might be as good as it gets.

    personal use of battery storage might well be a winner - so doing on a small scale what seems to be impractical on the national scale.
    Current Eon Next customer, ex EDF, Zog and Symbio. Don't think dual fuel saves money and don't like smart meters. Chronologically Gifted. If I offend let me know by private message, but I’ll continue to express my opinions nonetheless.
  • wizzo227's Avatar
    Level 22
    Well, there is a downside to half-hour priced electricity if you are one of the many who'll just switch stuff on because its after-school time. Right now, if you are on the tariff which got me cut price heating the other night, don't switch anything on if you can possibly help it because prices have gone to the nastiest which I've seen for a while:
    17:00 - 17:30 58.88p/kWh
    17:30 - 18:00 65.96p/kWh
    18:00 - 18:30 63.67p/kWh
    18:30 - 19:00 67.95p/kWh
    19:00 - 19:30 38.15p/kWh
    19:30 - 20:00 32.85p/kWh

    Thats right: 66p/kWh
    I had the heat pump on for the cheapest hours after lunch so I'm good for the rest of this evening unheated.
    That's right - neither gas nor electric heating used for a couple of hours.
    That long time constant before indoor temperature changes is another advantage of living in a moderately well insulated home with a small exposed perimeter.

    So if you want to become capable of exploiting cheaper electricity and ignoring expensive electricity, get insulated.
  • meldrewreborn's Avatar
    Level 91
    @wizzo227


    TOU pricing can be both a carrot and a stick. You've illustrated both in a very clear manner.

    I'm all for the carrot approach - reward people for using at off peak timings or reducing consumption at peak periods. I'm not so keen on the stick approach which would catch the unworldly wise part of the population dearly. Which is why I'd press for a fall back position of total consumption in a period (1 Month?) being chargeable at no more than the price cap, thus overiding TOU pricing if that proved to be more expensive. So TOU might be cheaper, but couldn't be more expensive than the price cap.
  • wizzo227's Avatar
    Level 22
    @meldrewreborn
    That would be sure to fail, because who'd sell surplus electricity for massively less than price cap at windy times and then at limited price for price cap reasons at after-school-peak no-wind times ? A biller desk might get away with it for a few months and then go bust costing everyone else's biller desks for offering below-cap but never above-cap. If instead, the p/kWh goes up commensurately with the cost of hurling fuel into a furnace somewhere, then at least some people will notice that now is a bad time to be using extra and postpone their major loads, hence avoiding overuse of fuel or expensive batteries. I can still use the internet and run this raspberry pi; Household use shows 120 Watts while the fridge motor is running and will soon be back below 0.05 kW. I just won't be putting the oven on for chips.
  • meldrewreborn's Avatar
    Level 91
    @wizzo227

    it would be up to suppliers to devise their tariffs in the future. Indeed all current supplier do exactly as you say would be sure to fail, because they set prices at a minimum of 3 months in advance with no certainty of half hourly prices.

    you would have thought that anybody on the variable next tariff would shift to next pledge which is virtually the same but guaranteed to be cheaper. I don’t have the figures for how many have but we’re often told that the massive proportion of customers are still on default tariffs, so hence why customer inertia (still after 40 years of deregulation) will mean TOU becomes Niche only.
    I’m not aware of any places where half hourly electricity pricing on a TOU tariff has become popular in a domestic market.

    some parts of Canada has compulsory banded TOU pricing but it’s set in advance and not continuously variable. Opinions differ on whether it’s beneficial - entirely predictable. Here, those adversely impacted by standing charges would prefer tariffs to be just unit charges. That’s life!
  • DebF_EONNext's Avatar
    Community Team
    @Andy65 I agree. I believe it's all about having informed choice, researching what will work best for you and knowing what your needs are, such as - do you need a flat rate, do you use more in the early hours, do you have kids on devices (little energy vampires!) do you have storage or an EV, do you live alone or a family of 5 etc

    Once you know what you need and how you use your energy you can look at what's available and what suits you.

    TOU is a fantastic idea and like you say Andy65 some people get really invested in it where as other people just want to pay their bill and forget about it. For me I no longer have solar, I don't have an EV and I work from home so TOU probably isn't for me at the moment but in future who knows?!
    "Green is the prime colour of the world and that from which it's loveliness arises"-Pedro Calderon De La Barca 🌳

    E.ON Next Poll - How much do you know about the Priority Service Register? - If you have a spare 2 minutes 🕑 we'd love if you complete our poll about the Priority Service Register 🤗

    Wondering about heat pumps? Check out this thread 👉 Air source heat pumps in winter: Busting the myth!
  • wizzo227's Avatar
    Level 22
    Another weekend, and we have a named storm approaching Scotland. Will EoN make it possible for their customers to access comparable pricing to that which I'm on ?
    In Z time (GMT not summer time), the next dayahead prices have just been published out to 22:30Z Monday
    The other company seem to mostly pass through wholesale costs at fixed-markup plus daily standing charge, instead of selling retail electricity at fixed cap price plus daily standing charge. So on those rare occasions when the stupid hedge funds are collecting insurance to protect a cap price, I get a slightly negative electricity price instead of a windmill somewhere getting paid to curtail generation. If I can switch stuff on at home then I should.

    So overnight 23:30Z (00:30 BST) until 05:00Z (06:00 BST) I can switch on every electric heater in the house which is even marginally gainful, and doing so will cost the national grid slighly less than would making curtailment payments to a wind farm.

    The next improvement which I'd like to see is for such price signalling to be strongest nearest to those windmills in the path of the storm, such that transmission and distribution costs could be slightly decreased if somebody north of Glasgow got stronger incentive pricing than me. Formally that could be done with node pricing with time variability published in advance. Never mind that such might lose my freebie for me; if that somewhat incentivises building the next renewables nearer to where they get used then it would lessen the increasing need for new big pylons.

    Before daily standing charge, incl. being inclusive of 5% VAT, the published uk-wide pricing until Monday (tomorrow) evening from Sunday (today) afternoon are :

    end start p/ ex. p/kWh incl
    22:30 22:00 15.39 16.1595
    22:00 21:30 18.81 19.7505
    21:30 21:00 18.47 19.3935
    21:00 20:30 21.04 22.0920
    20:30 20:00 16.50 17.3250
    20:00 19:30 18.53 19.4565
    19:30 19:00 19.45 20.4225
    19:00 18:30 22.00 23.1000
    18:30 18:00 42.22 44.3310
    18:00 17:30 42.91 45.0555
    17:30 17:00 39.04 40.9920
    17:00 16:30 37.00 38.8500
    16:30 16:00 33.59 35.2695
    16:00 15:30 31.21 32.7705
    15:30 15:00 16.50 17.3250
    15:00 14:30 17.60 18.4800
    14:30 14:00 16.54 17.3670
    14:00 13:30 17.15 18.0075
    13:30 13:00 16.78 17.6190
    13:00 12:30 18.15 19.0575
    12:30 12:00 17.12 17.9760
    12:00 11:30 17.65 18.5325
    11:30 11:00 16.38 17.1990
    11:00 10:30 16.95 17.7975
    10:30 10:00 13.59 14.2695
    10:00 09:30 14.30 15.0150
    09:30 09:00 15.84 16.6320
    09:00 08:30 17.69 18.5745
    08:30 08:00 21.60 22.6800
    08:00 07:30 20.30 21.3150
    07:30 07:00 23.10 24.2550
    07:00 06:30 18.65 19.5825
    06:30 06:00 13.38 14.0490
    06:00 05:30 9.65 10.1325
    05:30 05:00 -1.61 -1.6905
    05:00 04:30 -1.61 -1.6905
    04:30 04:00 -0.34 -0.3570
    04:00 03:30 -0.28 -0.2940
    03:30 03:00 -0.92 -0.9660
    03:00 02:30 -1.10 -1.1550
    02:30 02:00 -0.92 -0.9660
    02:00 01:30 -0.73 -0.7665
    01:30 01:00 0.34 0.3570
    01:00 00:30 -0.66 -0.6930
    00:30 00:00 -0.21 -0.2205
    00:00 23:30 -0.55 -0.5775
    23:30 23:00 -1.61 -1.6905
    23:00 22:30 2.20 2.3100
    22:30 22:00 -0.69 -0.7245
    22:00 21:30 4.40 4.6200
    21:30 21:00 1.32 1.3860
    21:00 20:30 5.50 5.7750
    20:30 20:00 4.13 4.3365
    20:00 19:30 8.80 9.2400
    19:30 19:00 10.27 10.7835
    19:00 18:30 16.00 16.8000
    18:30 18:00 29.97 31.4685
    18:00 17:30 30.60 32.1300
    17:30 17:00 29.40 30.8700
    Last edited by wizzo227; 20-10-24 at 16:36. Reason: column alignment