"Plug and play" grid tie inverters

Has anyone ever used a "plug and play" grid tie inverter? (An inverter that hooks up to a solar panel, and then plugs into an AC outlet) If you have, could you please post your experience with these? I am looking into purchasing one.

For those who don't know what I'm talking about, here is an example of one;http://www.gogreensolar.com/products/250-watt-grid-tied-inverter



Also, someone told me that not all electric meters can handle putting electricity back into my house. Is this true? And if it is, is there a way to tell if I have a meter that does allow me to?

Thanks a bunch!

Comments

  • icarusicarus Posts: 5,084 ✭✭✭✭
    Re: "Plug and play" grid tie inverters

    Please do a search on this site,,, there has been considerable considerable conversation on the subject so there is no reason to do it all over again.

    One note: The units are NOT UL listed and CANNOT be plugged in LEGALLY to the grid. You also run into insurance issues!

    Tony


    PS This is one of the discussion threads: http://forum.solar-electric.com/showthread.php?t=3051&highlight=simple+grid+tie+inverter&page=3 There are sure to be others!
  • BB.BB. Posts: 26,204 admin
    Re: "Plug and play" grid tie inverters

    GoGreenSolar appears to be a residence (at least where the RMA's are sent, with at least one other company registered there).

    What they are selling may work, but as Tony/Icarus said, it is difficult to believe that anyone will allow you to legally connect this inverter/system using the standard net metering agreements.

    For example, if you search for Delaware net metering agreement you will find:
    PV Installations Less Than 25 kW
    Most, if not all, residential installations and many non-residential installations fall into this size category of PV installations. For these installations, the interconnection requirements of Delmarva Power and the Delaware Electric Cooperative are fairly straightforward and standardized. Some basic requirements are:

    • PV systems must comply with the Institute of Electrical and Electronic Engineers standards for PV Systems.
    • PV modules need to be certified by a nationally recognized testing laboratory as meeting the requirements of a Underwriters Laboratory (UL) standard.
    Inverters must be certified by a nationally recognized testing laboratory for safe operation and certified as meeting a UL standard.

    For PV installations less than 25 kW, solar contractors usually fill out the appropriate interconnection agreement forms and make sure a PV system is properly connected, although the utility account holder’s signature on an interconnection agreement is required.
    • Will the vendor stand behind product. Don't know.
    • Will the inverter work? Don't know.
    • Will it be safe? Don't know.
    • Will it be legal? No.
    • Will your home be safe. If you have lightning in your area, probably not.
    • Will it meet building & NEC codes. No.
    • Should you do it. No.
    • Has it been done by others before and nothing happened. Probably.
    • Is it worth $0.10-$0.20 of power per day per inverter--not to me.
    $350 inverter and $1,250 for 250 watts of solar panels, assume 200 watts * 4 hours per day average per year, assume $0.15 power cost:

    ($350+$1,250)/(200w*4 hours*365d/y * $0.15pkWhr *1w/1,000kW)=36.5 years payback...

    And, presumably, this installation would not (legally) qualify for any State or Federal rebates/tax credits.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Posts: 5,084 ✭✭✭✭
    Re: "Plug and play" grid tie inverters

    My opinion of such hardware would be much more favorable if you could get UL or CSA listing, and it was acceptable to the utility. Since these products seem to have anti-islanding so that they can't back feed a dead grid it seems that they could be made safe. It these were listed and legal, it WOULD allow people to put in very small scale PV systems. The wouldn't really pay, but it would be a way for people to see how the whole thing works,,especially if they couldn't afford a large conventional grid tie system.

    Tony
  • BB.BB. Posts: 26,204 admin
    Re: "Plug and play" grid tie inverters

    Forgot to answer your other question...

    Older mechanical meters (over a decade or so) old, may turn both forwards and backwards.

    Newer mechanical and electronic kWhr meters may or may not turn backwards--it is up to your local utility and how they ordered their meters.

    Sometimes, you can search for your brand and model of meter and find the specifications (and options markings) online.

    Depending on the loads in your home, you may never generate enough energy to turn your meter backwards at that low of power levels (200 watts or so will power a fridge and standby loads for TV's, home entertainment systems, some cell phone chargers, door bell transformer, etc.). In those cases, your meter will just simply turn "forwards" at a slower rate.

    Lastly, if your utility suspects you have connected any GT Inverter without filling the proper paperwork (my meter has a notice to the meter reader that the meter does turn both directions--plus there are solar power warning stickers on the meter boxes and disconnects, and a note on my account of same)--The utility has the right to disconnect your electric service. And your local building department could tag your home not fit for habitation without electric power.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: "Plug and play" grid tie inverters

    Thanks a lot for all your help. After reading what you both have to say, I'm pretty sure I'm not going to buy a plug and play grid tie inverter ;)
  • eman21401eman21401 Posts: 3
    edited April 1 #7
       Hello, I bought two plug and play GTI units on ebay recently. They work great and are perfectly safe on dedicated circuits... Yes, these units do have anti- Island protection as per NEC regulations. Which brings up the question, Why hasn't the NEC properly addressed these useful devices by now ? Yes, they are not UL approved or listed, but they should come up for review. They have been out for several years. They could make quite a difference. I started off with a battery based system.
  • eman21401eman21401 Posts: 3
    looking forward to your comments...
  • mike95490mike95490 Posts: 7,022 ✭✭✭✭
    eman21401 said:
       Hello, I bought two plug and play GTI units on ebay recently. They work great and are perfectly safe on dedicated circuits... Yes, these units do have anti- Island protection as per NEC regulations. Which brings up the question, Why hasn't the NEC properly addressed these useful devices by now ? Yes, they are not UL approved or listed, but they should come up for review. They have been out for several years. They could make quite a difference. I started off with a battery based system.
    The device mfg has to submit a couple devices to UL and pay for the testing.  If that's too hard to do, skip the test and sell from ebay - more profit and they have "plausible deniability" when your house burns down.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • jonrjonr Posts: 666 ✭✭✭
    You say that they are "perfectly safe" and meet the regulations.  How can you be sure of this?
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