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Question on net metering

Discussion in 'Photovoltaics' started by george1234, Jun 20, 2006.

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  1. george1234

    george1234 Guest

    I have a grid tied PV system and live in a net metering state,
    Massachusetts. This spring, in one month I delivered about 100 kwh to
    the power company. Normally I'm a low net user, but I was away that
    moth and became a net generator. After one or two polite reminders the
    electric company finally credited me $6 ( or 6 ¢/kwh) . I was
    expecting $15 (15 ¢/kwh, which is what I pay). When I asked for an
    explanation of the difference, they explained they credited me at the
    wholesale rate.

    Normally, when the meter goes one way or the other they credit me at
    the rate I buy ( at least I hope they do, who really knows with the
    electric meters they install) Because I had the misfortune to be a net
    generator when they got around to reading the meter, I get penalized.

    My question is what is the net-metering law in Massachusetts? I
    realize chances of anyone knowing the law is low, but could anyone
    give me a clue how to find out. I'm tempted to take the electric
    company to small claims court to collect the $9 they owe me .

  2. george1234

    george1234 Guest

    FWIIW.. looks like the electric company was correct, net excess
    generation is treated differently than ordinaly net metereing. Excess
    generation is "Credited at average monthly market rate to
    customer’s next bill" whereas ordinary net metereing with no excess
    generation is done at the retail rate

    Interstate Renewable Energy Council (IREC) Connecting to the Grid
    Project State and Utility Net-Metering Rules
    (Updated December 2005)
  3. Guest

    In California, PG&E-land, I am a net metering customer, and I have gone
    below zero on my bill a few times. There is an "annual true up", where I
    pay them for any shortages, and they zero out any credits ;-(

    "Net excess generation (NEG) is carried forward to a customer's next bill
    for up to 12 months. Any NEG remaining at the end of each 12-month period
    is granted to the customer's utility. Customers subject to time-of-use
    rates are entitled to deliver electricity back to the system for the same
    time-of-use (including real-time) price that they pay for power purchases."

    This isn't done on a month to month basis.

    Perhaps if you had waited another month, you would have gone back into the
    consumer portion, and received a small bill, maybe not. should have pointers to programs in your area.
    "allowed customer-generators to carry NEG forward -- credited at the
    average monthly market rate -- to the next month's bill. "

    "monthly market rate": I'd need a definition of that.

    Or, your local utility's pages should explain it. "your home" "generate yor own power" explains my
    "Standard Net Energy Metering" program.
  4. Guest

    This would make more sense to me:

    They basically defined the term "Avoided Cost" in
    regard to IPPs, Independent Power Producers, as the
    costs that would be AVOIDED had a "New Power Plant"
    NOT been built...

    If you provide an extra 1 kW at peak time, the utility may not have to
    build a new power plant... so maybe the avoided cost is the cost to build
    1 kW of new plant minus the cost to deliver your power to others. I wonder
    how to calculate that.

    I met a "negawatt trader" who would look at the NY Power Authority auction
    web site and bid on meeting demand on a few peak summer afternoons when
    the cost per kWh rose to $1 or so. If he won, he would ask a few large
    apartment building managers to turn off the AC from (say) 2-3 PM, and
    get paid as if he had provided real power rather than reducing demand,
    with extra green credits for doing so without any pollution. Perhaps
    there's a way to relate this to avoided cost in the legal sense.

  5. george1234

    george1234 Guest

    On Tue, 20 Jun 2006 23:38:16 +0000 (UTC),

    I tried that last year, and they just forgot about crediting me. This
    year I decided to be more persistent, polite but persistent

    I don't believe the company is deliberatly difficult, I just think
    that residential co-generation is such a small part of their business,
    they do not properly accomodate it

    For example, last year they switched the old mechanical meter to a new
    one that could be read by radio. Alas, to discourage theft, the new
    meter had a ratcheting mechanism that prevented it from going

    This year they installed a all electronic co-gen meter, that is
    designed to read backwards ( and presumeably to be read by radio).
    Alas, it went down to zero and stalled in that time I was away . I had
    to call to get one that worked

    I don't believe the errors are deliberate, I believe they just lack
    experience on the residential co-gen accounts and it shows in poor
    implementation in billing and metering.

    In this case, teh company was correct according to Ma net metering
    laws. The only explanation I got was that "we pay you at the
    wholesale rate" without explanation of NEG. i dug deeper because my
    expereince is the electric company makkes mistakes in these matters.

  6. Guest

    Well, that wasn't Net Metering... ;-(

    In California, there were different eras.
    First, you just hooked it up, and nobody knew (which sounds like what
    you've got, now).
    Then PG&E said that wasn't fair, and installed ratcheting meters.
    The solar lobby said that wasn't fair, and we got co-metering, which was
    two meters in parallel, each ratcheting in opposite directions, to pay at
    wholesale and buy at retail.
    Then came the bi-directional meters, which is an electronic version of the
    original. PG&E doesn't know when I'm pushing or pulling energy, they just
    know what the net effect is once a month.

    The radio meters are supposed to be coming next year.

    I have had a couple of negative bills so far this year. My current
    running account, to be cancelled or paid to PG&E next January, is $36.36.
    That should go lower, maybe negative, over the summer, and then be around
    zero in January.
    The PG&E meters are started at 50,000 to avoid that problem.
    I'm about 500 below "zero" now.
  7. daestrom

    daestrom Guest

    'Avoided cost' was a term used in NY when we were still a regulated utility
    state. The cost of generating one extra MWhr of electricity is the 'avoided
    cost'. Think of it as the 'marginal' cost of electricity. Certainly during
    peak periods, it can be quite high. But such 'peaks' don't happen all that
    often and between peaks, the 'marginal cost' is much lower. At times like
    2:00 AM on a spring night, it can be as low as $0.03/kWhr.

    So that brings in the question of time variability. Should the utility
    always pay the highest 'avoided cost' rate, of course not. Neither should
    it pay the lowest. Up until the last five or eight years, having detailed
    hourly generation costs and detailed hourly meter readings was a luxury that
    few could afford (meant time-of-day chart recorders and lots of hand data
    entries). The utilities told the PSC they wanted compensation for all this
    labor and calculations and the PSC saw that it would be quite a burden.

    So in many states like NY, the PSC would say either the IPP had to pay for
    extra metering or accept a flat-rate set by the PSC (was $0.06/kWhr in NY).
    The idea being that $0.06/kWhr was a sort of weighted-average of the avoided
    costs during peak and non-peak times. The PSC expected that that price would
    be a bit high in the first couple of years and attract a lot of IPP's (it
    did), but that the avoided costs of electricity would rise with increasing
    demand and be a 'bargain' after a few years. Problem was, demand didn't
    rise as expected and avoided costs never reached $0.06/kWh. In NY, Niagara
    Mohawk realized that they could actually produce electricity cheaper than
    the $0.06/kWhr most of the time and told the PSC they were screwed up.
    Eventually the NUG's (non-utility generators) would have to renegotiate a
    price with the PSC and NIMO, or let NIMO buy them out of their contracts (at
    considerable cost to the rate payers).

    Now with electronic meters and de-regulation in NY, any sizeable IPP can bid
    in an 'open market' and the price fluctuates with demand. The utility has
    very little to do with the pricing and passes the average cost of power from
    that market through to its customers. But home power systems are really too
    small to get into that market. And the price is usually *not* high enough
    to be very attractive. After all, how many 15-minute blocks a year does the
    price reach $1/kWhr?

    When the utility in NY credits for a small home system, they credit just the
    energy cost. (NY bills are 'unbundled' and have the costs of energy and
    delivery separated). This is only about half of the retail price. But NY
    only allows 'net-metering' on solar systems, not other renewable/micro

    'negawatt trading' is still practiced, but a bit differently. The NYISO
    (not the New York Power Authority, they are two different things) charges an
    extra fee for 'congestion' that is related to peak demands. If a large
    customer and their IPP can coordinate to not use a lot of power when
    'congestion fees' are high, they can save themselves a fair amount of money.
    And the NYISO can pay some registered customers for 'voluntary curtailment'
    (they will 'shut off the lights' when asked).

  8. Guest

    That's what my neighbor did. He has a "bi-directional meter", which is a
    label affixed to the meter which was already there. I think TOU is an
    advantage to me. He must not. It depends a lot on A/C load in the summer,
    I think. I am running behind the last two days.
    My net generation specifically does not offset $5.77 per month in fees.
    Other than that, at the end of the year, can you get money back? I can't.
    A bill net consumer bill is paid once a year, a net generator credit is
  9. Guest

    My PECO friend says peak electrical energy sometimes goes for $5.20/kWh
    down here in PJM-land :)
    That negawatt trader rarely bid...
    That depends on how you interpret the supreme court decision. Utilities are
    obliged to meet peak demands, no? It won't always do to say 'we can't
    provide your electricity now, but we'd be happy to help at 2 AM."

  10. Guest

    My pre-sale analysis has a large differential in the projections for TOU
    verses non-TOU. The projection for June is non-TOU: -$2.25 TOU: -$44.67.
    For the actual June bill, I have -176 kWH Peak, 326 off-peak, billing
    -$25.77. If that was straight rates, it would be 150 kWH overall usage, at
    $0.11430. That's a difference his month of $42.92 between TOU and non-TOU.

    The meter installation for TOU was $277.00, but that should amortize in the
    in less than the first year.
    But you can never get money back, right? Overgeneration credit is lost in
    the annual trueup.

    And of course, we aren't with the same power company... I was just
    wondering about the payback for a credit on trueup day, which doesn't exist
    for me. (Sometimes I think we're in different states.)
  11. daestrom

    daestrom Guest

    Detroit Edison had a program a few years back where you could connect
    certain high power loads to a 'black box' of theirs. Things like electric
    hot-water heater and central air. The box allowed them to shut off power to
    the box during severe peaks in order to reduce demand. The program put a
    flat-credit on your bill every month that it was activated during the month.

    Of course, some folks might try to get around the box and still get the
    credit. There were some problems like that. Program was terminated in
    favor of TOU tariffs and some other ideas.

  12. daestrom

    daestrom Guest

    That was probably on the 'spot market'. Yes, according to NYISO, the
    'real-time' market price in NY has gone that high on a few occasions.
    Usually that high a price only lasts for 30 minutes or so.

    Look under real-time market and archives for the summer months and you'll
    see similar 'peaks' in pricing.
    But if the IPP only produces power between 12 AM and 6AM, should they be
    paid the 2PM rate? Of course not, but that is effectively what was
    happening. IPP's were not being built to meet the peak demands of customer
    usage. They were built by non-utility business decisions to make money.
    Many were co-generation designs whose primary purpose was to supply energy
    to a nearby industrial customer. Some were built to supply process steam to
    an industry customer on first and second shift, then when the industrial
    plant cut back on third shift, the steam went to generation. So the only
    'avoided cost' for the utility was base-load power. Or the IPP produced
    electricity for use in their mill during first and second shift and sold the
    power on third shift.

    Because small IPP's were not required to provide 'firm commitments' on power
    production, they did little to reduce the utility's problems meeting peak
    demand. This was the basis for the utilities challenge to the issue of
    paying 'avoided cost'. It was actually *increasing* the cost to consumers.

    Some utilities like Niagara Mohawk were able to demonstrate to the PSC that
    customer electric rates would be *lower* if NiMo simply bought out the IPP
    and shut the plant down and then operated their own base-load units to
    supply the power. Even if the cost of the buy out was 'allowed' and passed
    on to the rate payer. At the time, NiMo was being forced to curtail
    base-load plant operation (at $0.022/kWhr) because so many IPP's were
    supplying power that NiMo was forced by law to purchase (at the state
    mandated $0.06/kWhr).

    What seemed like a good idea (giving IPP's equal access to T&D) had the
    'unintended consequence' of raising the cost of electricity for everyone.

  13. Guest

    Agreed. They should be paid the going rate at the time of day.

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