Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 55 replies
  • Subscribers 32 subscribers
  • Views 4647 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

smart meters: questions to ask?

DavidMartin
My electronics does not quite extend to domestic power systems so would appreciate advice: 


We have a 4kW PV installation (which works well), but I understand some smart meters are incompatible with PV installations.  Partly for that reason I have prevented installation, so far.

I also understand that smart meter standards are still settling and not all meters being installed are guaranteed to work for the forseeable future, through changes in suppliers, etc.

There also seem to be issues around safely and future maintenance of some smart meter systems.


So ... can the team suggest questions I should ask to reduce the risk of a 'bad' smart meter installation ?


Thanks.
  • 0
    The problem with underfloor heating won’t be the meter as such, rather the comms method they have chosen due to marginal signal strength. 


    Regards,


    Alan.
  • 0
    I would guess (and it IS a guess) that some smart meters are so NOT smart that they can't cope with energy flowing in the reverse direction.  I've seen this with modern electronic meters (not smart ones) that simply flash RED (reverse energy detected) and cease totalizing for a bit. A normal (to me) 'twisty dial' meter would simply go backward, thus paying you the same price as the power company charge you. They (power selling companies) don't like this.  Not one bit.


    IMnsHO, smart meters are a scam.
  • 0

    I would guess (and it IS a guess) that some smart meters are so NOT smart that they can't cope with energy flowing in the reverse direction.  I've seen this with modern electronic meters (not smart ones) that simply flash RED (reverse energy detected) and cease totalizing for a bit. A normal (to me) 'twisty dial' meter would simply go backward, thus paying you the same price as the power company charge you. They (power selling companies) don't like this.  Not one bit.



    I thought the specification for all smart meters required them to cope properly with exports too - although as Alan says, it may need to be enabled (to regard backward flow as legitimate rather than an indication of tampering). Even traditional meters shouldn't run backwards* when exporting - when you install a PV or other parallel generation system you're obliged to tell your supplier and they in turn are ment to ensure that your main meter is of the ratchet/pawl type that is prevented from running backwards (most of the later spinning disc types were anyway).


    * I've noticed that mine does run backwards slightly - when exporting starts it run backwards up to one rotation of the disc - as it seems the ratchet/pawl mechanism only engages once per rotation.


      - Andy.
  • 0
    Smart Meters can cope with reverse power, and this could have been used, However, the British government in its wisdom decided that the householder would be paid a unit rate even for electricity used by themselves, hence two meters, on registering import only from the public supply, and one registering the renewable generation. This, and the fact that the renewable and standard supplies can come from different companies has just added to the mayhem. The meter for the public supply must be set so it does not count reverse power, and also need to have its anti-tamper flag ignored by the supplier. This is one of the reasons you must.inform your supplier when you have renewable generation installed. 


    The easiest option would have been to record import and export power from the public network, which can easily be done on a single device, both with conventional and smart metering. 


    Regards,


    Alan.
  • 0

    ebee:

    The very first question to ask is

    "What benefit is a smart meter to a sensible consumming customer? "




    There are many benefits. Here are a few: 


    • The meter does not need a monthly or quarterly read, and estimated bills are not required. 

    • Once all conventional meters are removed, meter readers are not required. 

    • Easy identification of areas without power is possible, cutting the length of power cuts. 

    • Supply tampering is easier to spot, preventing this “lost” electricity having to be paid for by other customers. 

    • The meter can be converted from “credit” to “pre-payment” and back again without having to visit the property to change the metering equipment. 

    • With the “pre-payment” option, alerts can be sent to the bill payer when the meter is running out of credit. 

    • The meter operator can get a good idea of the health of their devices without having to visit them often. 



    Regards,


    Alan.
  • 0
    Thanks all, esp Chris & Andy, this has been enlightening.


    So a smart meter won't be able to be used for remote reading of my PV generated, hence visits to the property are still required, I understand.

    Even though a smart meter could, it seems, log all exported power, but that's not the same as generated.

    Do we think that at some time in the future my PV meter might (need to) be connected to the house smart meter in order to be remotely readable?


    The north/south divide is v interesting (we're firmly south) and also the question on wireless power to penetrate house walls.  Our fairly new house has insulation between the brick/block leaves comprising insulating slabs with foil on one face. Which makes a significant barrier to mobile phones in the property, so also might affect the smart metering.   I don't quite understand the underfloor heating point, is this wet or electric UFH?  Ours is wet!
  • 0

    I don't quite understand the underfloor heating point, is this wet or electric UFH?  Ours is wet!



    I'd guess a couple of possibilities - in the case of an electric system the close zig-zags of wiring might approximate to a crude farady cage (or possibly a large aerial that might radiate any noise on the mains), or that underfloor heating heating usually goes hand-in-hand with large expanses of foil faced insulation board - which as you say can reduce radio signals significantly.

       - Andy.
  • 0

    Potential:

    Benefits to the customer?

    Not a lot, if any at all.  It is all a con.




    I was just offered a SMETS2 by my supplier. So I did some calculations.


    [Aside from my other fear that hackers could remote disconnect me - the SMETS2 does appear to have a remote controlled contactor inside. BigClive took one to bits. And IME what's state of the art encryption and security on the data comms side today, is tomorrow's exploitable code. There isn't a single encryption and security implementation over HTTPS (SSL/TLS) or SSH that has lasted the course - they've all been advanced and improved and replaced. Can we rely on that happening here?]


    Back to economics:


    My tariff now is 13.98p/kWh


    The tariff on offer for SMART would be, from my supplier:

    4pm-7pm - 41.94p

    Other times - 11.67p

    11pm-7am - 7.91p


    Standing charge the same so ignore.


    The only 2 appliances I have that I can choose when to run in any meaningful way are washer/dryer and dishwasher. I measured the consumption of both for a typical day averaged from 3 days use:


    WasherDryer - 4.23kWh

    Dishwasher   - 2.65kWh


    So if we operate both overnight, we save 41.76p/day or £152/year. Seems good.


    But if someone accidentally runs or has to do both in the 4-7pm peak, the day cost rockets to 192p *extra* over non smart and eats up the savings for over 4 days.


    In reality, on certain days we run the dishwasher twice so one at "other" rate and one overnight. The washer/dryer often builds up washing to do and I end up clearing one overnight and 2 in the day on my at-home days.


    For anything else, cooking is going to shoot up (4-7pm) and always on (computers, fridge etc) works out at an average of 14.25p/kWh over the day so slightly worse.


    Unless you have large loads than can be shifted to overnight or you have a small household and can set washing etc to always run overnight, I see no real gains. It won't take many "have to run machines 4-7pm - or I forgot about the times" to negate any savings for my household.


    I have declined mine and instructed then to replace with a dumb meter.



    Your milage may vary of course... If I had an electric car or storage heaters, I'd probably jump on it, though likely I would already be on a dumb Eco7 tariff anyway...


    Cheers, Tim

  • 0
    It seems perfectly reasonable to me for the electricity companies to seek to reduce peak demand by pricing mechanisms.


    Dishwasher - set to run over night so that the dishes are clean for breakfast - no problem there.

    Shower - get up bright and early and finish by 07:00.

    Laundry - by all means wash over night, but then either everything gets creased, or the machine continues with its anti-crease function all day. Unless you attend to it before work.

    Cookery - not difficult to prepare dinner after 19:00, but a problem if you have young children at home.


    Yes, it's doable with a bit of effort.
  • 0
    Pricing mechanisms  ... interesting subject ... does having a smart meter automatically mean a change in tarrif?   Not something I had forseen.

    I can see, however, that this has potential benefits to both consumer and electricity company. 

    As long consumers are organised enough to schedule their electricity usage.

Community Rules & Guidelines