Meter running backwards

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System
System Posts: 2,511 admin
in General Solar Power Topics #1
If the large wheel in your meter is going back does it mean that the meter is actually recording back???
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  • SkiDoo55
    SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    #2
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    Re: Meter running backwards

    You have to watch it for a period of time as some mechanical meters have a one-way ratchet on the dials. The far right numbered dial is the one that will move first.
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  • jcgee88
    jcgee88 Solar Expert Posts: 154 ✭✭
    #3
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    Re: Meter running backwards
    zank wrote: »
    If the large wheel in your meter is going back does it mean that the meter is actually recording back???

    Probably not, especially if it is an old analog meter. These meters
    have a large flat disk that will spin either forward or backwards.
    The problem is that they are not mechanically geared to spin
    the kwH dials backwards, which is what counts for getting
    credit from the power company. The company will swap that
    out for a new digital meter, which can "spin backwards."
    However, the new meter won't have the disk that you can
    watch spin backwards; mine simply has an arrow that lights
    up when I am doing a net positive generation. Since it takes
    many minutes to count up to a full kilowatt hour, well, the
    thrill is gone.

    When was your house built?

    John
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #4
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    Re: Meter running backwards

    Actually, my old Analog/mechanical meter (decades old) ran just fine backwards (and decremented the reading).

    As the others have said--It all depends. They started placing one-way ratchets on older meters a decade or so ago when people started generating their own power...

    Some of the newer meters (digital only?) will simply increment (go up) no matter which way the power is flowing (i.e., they will charge you for generating power too).

    But in the end, it was very much up to the utility how they purchased their meters and how their meters were designed/programmed to behave.

    In the end, unless you have net metering with your utility--They will be all over your bill/home trying to figure out what went wrong if you have a month or two of declining bills. And, they (usually) have the right to disconnect your power until the "problems" have been resolved.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #5
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    Re: Meter running backwards
    Probably not, especially if it is an old analog meter. These meters
    have a large flat disk that will spin either forward or backwards.
    The problem is that they are not mechanically geared to spin
    the kwH dials backwards, which is what counts for getting

    Wrong. The old analog meters unwind just fine. It's the newer analog ones, 1995+ that have a one way gear in them.
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  • jcgee88
    jcgee88 Solar Expert Posts: 154 ✭✭
    #6
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    Re: Meter running backwards
    mike90045 wrote: »
    Wrong. The old analog meters unwind just fine. It's the newer analog ones, 1995+ that have a one way gear in them.

    My old meter was installed before I moved in, which was in 1982.
    It definitely did not run the dials backwards. I watched and
    watched the disk spin backwards, but the kwH dial would not
    budge. When I looked behind the facade and saw the gearing,
    I could then see why.

    So...like all things, it's whether you are lucky or not!

    John
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  • Roderick
    Roderick Solar Expert Posts: 253 ✭✭
    #7
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    Re: Meter running backwards

    Just one data point. Our house was built in 1974, and had the original meter when we first installed solar. It decremented just fine. Pacific Gas and Electric, California.
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  • Missouri Bound
    Missouri Bound Registered Users Posts: 5 ✭
    #8
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    Re: Meter running backwards

    Interesting topic. I just hope that you aren't going to leave it that way. Whenever you are generating electricity, you must disconnect from the utility. You are creating a potentially hazardous situation which just is not allowed. If the power company determines that you are generating electricity AND still connected to the grid, expect large fines and possible permanent disconnect.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #9
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    Re: Meter running backwards

    With Grid Tied / Utility Interactive Solar PV Inverters (and others) -- They are designed to safely connect to the grid and drive energy into the home and even back out the meter...

    Of course, it requires building permits, inspections, licensed installer/electrician/sometimes a PE (professional engineer to review building and PV Array structure to be safe in storms/earthquakes/etc.), and pre-approval/inspection/approvals from the electric utility too. And many times the utility will change out to another meter that meets their particular billing requirements.

    And not all utilities will approve net metering.

    And, a solar array / GT system installed incorrectly can be a fire/shock hazard.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #10
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    Re: Meter running backwards
    Missouri Bound wrote: »
    Interesting topic. I just hope that you aren't going to leave it that way. Whenever you are generating electricity, you must disconnect from the utility. You are creating a potentially hazardous situation which just is not allowed. If the power company determines that you are generating electricity AND still connected to the grid, expect large fines and possible permanent disconnect.

    Not necessarily.
    A legal grid-tie system is quite safe. Co-operation with your local utility should also ensure you get the right kind of meter which will credit you for surplus power produced.

    The fact that with the wrong meter you could actually be charged for surplus power is probably the best incentive there is for people to not have "gorilla" (guerrilla) installs.
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #11
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    Re: Meter running backwards
    Missouri Bound wrote: »
    Interesting topic. I just hope that you aren't going to leave it that way. Whenever you are generating electricity, you must disconnect from the utility. You are creating a potentially hazardous situation which just is not allowed. If the power company determines that you are generating electricity AND still connected to the grid, expect large fines and possible permanent disconnect.

    It is a long process and can be daunting at times to get the needed approvals for Grid Tie. The key to mine was to make sure the company has an engineer on staff for all the local building code revisions.

    Check with your utility and find out how they do grid tie. Mine offered $3 watt rebate which brought my out of pocket down alot.
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  • tallgirl
    tallgirl Solar Expert Posts: 413 ✭✭
    #12
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    Re: Meter running backwards
    mike90045 wrote: »
    Wrong. The old analog meters unwind just fine. It's the newer analog ones, 1995+ that have a one way gear in them.

    My house was built in 1999/2000 and the meter went both ways very nicely. It really is a crap-shoot which way this is going to go.

    If you have solar enough to support all loads during the day, you should be able to see some backwards movement of the digits dial between 9am and 3pm solar time. If not, you prolly need a new meter.
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  • strawbale
    strawbale Solar Expert Posts: 31 ✭✭✭
    #13
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    Re: Meter running backwards

    Our house was built and meter installed in 2002. It has the horizontal spinning disk. When our 7 kw system went into service on March 10 of this year the meter reading was 27,580 kWh. This morning it reads 24,010 kWh, so yes, it is running backwards. At this rate we should be down to 0 kWh in less than 4 years from now. Will it then keep spinning backwards past 0? I hope we don't get a bill for 99,990 kWh the following month!

    Strawbale
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