1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

4 Vs 5 Terminal dual-rate meter confusion

Discussion in 'Electrics UK' started by d000hg, 19 Nov 2018.

  1. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    42,681
    Thanks Received:
    2,705
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Talking of "spending less with an E7 tariff", I don't know how widespread it is, but in April my supplier (E.ON) changed its tariffs such that the 'best available E7 tariff' deal resulted in my saving as a result of having E7 (with no appreciable changes in total usage, or day/night usage patterns) falling to less than half of what it had been previously (the unlabelled {which I've only just noticed!} y-axis is £/year saving) ...

    upload_2018-11-20_19-55-53.png

    Kind Regards, John
     
  2. Sponsored Links
  3. flameport

    flameport

    Joined:
    10 Mar 2007
    Messages:
    8,473
    Thanks Received:
    1,570
    Location:
    Poole, Dorset
    Country:
    United Kingdom
    E7 and it's variants including the old 'white meter' rates were introduced at a time where overnight demand for electricity was low, most businesses being closed overnight.
    It made sense then to offer a lower price to increase demand, rather than have power stations idling and wasting away fuel.

    Today it's far less relevant, as night demand is higher than in the past, many industries use power 24/7 and future overnight uses such as large numbers of electric cars charging are likely to result in the demise of E7.
     
  4. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    42,681
    Thanks Received:
    2,705
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Yes, that seems to be what's happening. It was really the suddenness of the change which surprised me. In the 30 years prior to April 2018, the day/night ratio of prices we've been paying has remained largely unchanged and then, suddenly, the very marked change I illustrated - but it is beyond belief that the general increase in night-time usage has arisen suddenly and recently.

    As for the electric cars, yes, as I've suggested before, if it ever happened (not in my lifetime, I'm sure!) that most cars became electric, we might even reach the stage at which 'reversed' dual-rate tariffs made sense - i.e. if daytime became the 'low demand' period of the day!

    Kind Regards, John
     
  5. ban-all-sheds

    ban-all-sheds

    Joined:
    27 Aug 2003
    Messages:
    69,784
    Thanks Received:
    2,857
    Location:
    London
    Country:
    United Kingdom
    That's one of the least significant crimes against the people that have been perpetrated.
     
  6. I've been in three properties, each with 5 terminal E7 meters, and even with these, T4 goes to cheap rate too. In fact, in all three examples that I experienced, T5 was just used to supply a contractor, and the storage heaters/immersion just ran off T4.

    My last flat didn't have E7 (no storage heaters, just UFH), and I didn't see any significant increase in electric bills, despite heating my water overnight with an immersion and a single-rate supply.

    Hope this helps,

    Jon
     
  7. EFLImpudence

    EFLImpudence

    Joined:
    7 Jul 2010
    Messages:
    30,949
    Thanks Received:
    3,344
    Location:
    Retired to:
    Country:
    Portugal
    Ok. Could that be because the property used to have E7?
    I can't imagine the suppliers do that just to save the householder having to buy a timer.

    No, but the point is, the bills would be dearer if you had E7 and only used it for the immersion because the day rate would be higher than your single rate.
     
  8. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    42,681
    Thanks Received:
    2,705
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    It's probably not so much the suppliers as the meter manufacturers, and if their standard off-the-shelf meters have a rate-switched T5, it's probably cost-effective for the suppliers to just buy them in bulk - and T5 can then be used either a 'storage heater CU' (such as many may still have, from the earlier E7 arrangements) or to feed a contactor (if there is just a single CU).

    Kind Regards, John
     
    • Like Like x 1
  9. The properties did have E7 when I lived there. Everything went cheap during off-peak, even when it was connected to terminal 4.

    Indeed - I was pointing out that my experience supports the advice given here - that E7 without storage heaters probably isn't the right solution.
     
  10. Sponsored Links
  11. Yep, this is what I would imagine also. In the cases I experienced, I'd imagine it was to avoid running two "big" cables from the communal meter area, along with the cost saving of a single CU as you pointed out.
     
  12. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    42,681
    Thanks Received:
    2,705
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Yes, that's the usual (maybe universal) arrangement now - but there was a time when the off-peak electricity was only that specifically supplying the storage heaters (everything else remained at 'day rate' 24/7) - hence a time-switched contactor or the 'T5' output from the meter (in either case 'under the control of' the supplier).

    Kind Regards, John
     
    • Thanks Thanks x 1
  13. SimonH2

    SimonH2

    Joined:
    4 Nov 2010
    Messages:
    5,403
    Thanks Received:
    554
    Location:
    Cumbria
    Country:
    United Kingdom
    Had you not noticed how much nuclear has shut down over the last few years ?

    But back to the OP's problem. Yes it looks like he's got one of those borderline properties that are already ILLEGAL to rent out on a new tenancy, but the EPC surveyor has pointed out a way to get the extra few points to make it legal. Regardless of how daft it is, it's a way for the OP to be able to start a new tenancy. The reference to agent checks will be the checklist any agent will be using before they rent out a property on behalf of a landlord - and yes, some of them are "a bit clueless" and tend to insist on things that aren't mandatory because they don't understand the rules.
    It'll apply to existing tenancies soon (I forget the dates, doesn't affect my properties) which will mean some people being thrown out of their homes.
     
  14. JohnD

    JohnD

    Joined:
    15 Nov 2005
    Messages:
    61,508
    Thanks Received:
    3,239
    Location:
    Fife
    Country:
    Cook Islands
    and coal, of course, except as a fallback.

    Combined cycle gas are profitable and can be shut down when demand falls, so no need to sell cheap. You'll remember that in last year's cold winter, the country almost ran out of gas.

    As I type this, I see wind is producing 36.3% of demand, nuclear and gas together 40.2%
    http://www.gridwatch.templar.co.uk/

    People used to sneer at renewables.

    Once we've paid the Chinese to build our French nukes, I think smart meters will dynamically price down on windy days, and up on calm ones.
     
  15. SimonH2

    SimonH2

    Joined:
    4 Nov 2010
    Messages:
    5,403
    Thanks Received:
    554
    Location:
    Cumbria
    Country:
    United Kingdom
    Except that it is very expensive to run them at varying/intermittent load. It vastly increases maintenance costs due to thermal cycling and the resultant stress cracking, while also reducing the revenue (compared to running at constant load), and so increases the per-unit cost. This is significant enough that some gas stations have shut down* due to being priced out of the market - and there is considerable open-cycle gas which while suffering from the same thermal stress issues, has a cheaper capital cost and so the overall per-unit cost is lower.
    * Or would have shut down if not for intervention.

    And some of us still do - at least at those who promote them without also discussing the hidden/externalised costs. Lets see what the contribution is when we have another prolonged cold & calm spell like December 2010 - naff-all wind, no solar outside of the short days, increased demand due to all that electric heating. Of course, all those fossil fuelled stations that struggled to compete and stay open when faced with the unfair "competition"** from renewables are needed to keep the lights on.
    ** Where the fossil fuel station operator actually has to pay the competitor to undercut it, c.f. ROCs etc.
     
    • Like Like x 1
  16. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    42,681
    Thanks Received:
    2,705
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    To put that in context, if my location is anything like typical of the country as a whole, we have today had wind of a magnitude (brought down a large bit of one of my trees!) that we probably only see on a very small number of days per year.

    Kind Regards, John
     
    • Like Like x 1
  17. JohnD

    JohnD

    Joined:
    15 Nov 2005
    Messages:
    61,508
    Thanks Received:
    3,239
    Location:
    Fife
    Country:
    Cook Islands
    It looks like wind's been producing about as much over the last few days as it did for some days in October, January February and March. So more than during the summer.

    Today's been about the same as Tuesday and Wednesday, so not exceptional. A bit more than 7th-14th Nov. I don't think it's a small number of days per year.

    There is a slight growth over last year, which might just be more plant coming online.

    I suppose the industry must produce some month-by-month tables, but I haven't seen them.
     
Sponsored Links
Loading...

Share This Page