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Finally Grid Tie Solar with some backup off grid capability

Post in 'The Green Room' started by peakbagger, Oct 26, 2012.

  1. peakbagger

    peakbagger Minister of Fire

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    Looks like many folks, myself included, may finally be able to get a grid tie inverter that will run to a limited amount in off gird mode with the power out. Of course there are battery based grid tie units that provide all sorts of islanded capacity, but the trade off is significant extra cost up front, more expensive installation and battery replacements on 3 to 5 year intervals. I had just heard about SMA making a unit that might be the ticket and started a thread on another site I participate on. A SMA factory employee replied with limited details.

    http://www.solarpaneltalk.com/showthread.php?8565-SMA-Inverters-with-Emergency-backup

    My understanding from some web research is the Japanese government is rolling out a new very high dollar solar PV incentive and it requires "emergency backup capability" and therefore SMA is coming out with a product to meet the requirements.

    I expect 12 amps at 120 volts only when the sun is out is not much but with a UPS and some planning, I expect many folks might be able to keep some critical intermittent loads operating long enough each day to make it through an outage.

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  2. begreen

    begreen Mooderator Staff Member

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    Sunny and Outback have had this capability for a while now. I remember looking into this last year.
  3. peakbagger

    peakbagger Minister of Fire

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    Sunny (SMA) (, Sunny Island) and Outback ,( Radian) have battery based backup systems, but you pay a hefty front end cost and have to change batteries every few years. Of course if someone is willing to put in a parallel charge controller and inverter and run the array at lower voltage there are other options. The SMA (sunny) set up is the only one I have seen with no batteries, its basically an option on a standard grid tied inverter.

    quote="begreen, post: 1220851, member: 5"]Sunny and Outback have had this capability for a while now. I remember looking into this last year.[/quote]
  4. begreen

    begreen Mooderator Staff Member

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    In order to use the Sunny system you need to get the Sunny Boy grid-tie inverter and the Sunny Island inverter. There's a communications line between the two inverters that signals when the grid is down and transfers the control to the Sunny Island. It's a nice setup. You can insert a generator into the stream and the Sunny Island will manage the charge control.

    http://files.sma.de/dl/2485/SISYSGUIDE-KEN112916W.pdf
  5. macmaine

    macmaine New Member

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  6. nate379

    nate379 Guest

    2760 watts at 240v is about 12 amps. Maybe some inverters run on 120v, but 240v is much more common.

    The big headache with the backup is the UL Listing that requires the inverter to drop the feed if the grid goes down.
  7. begreen

    begreen Mooderator Staff Member

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    Interesting. Need to know more about that system. Do you know what it costs? I'm also wondering if it allows a genset tie in for charging on cloudy day stretches.
  8. macmaine

    macmaine New Member

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    Be green

    Solar city pushes the lease model for solar power
    One poster on another site said it was 10 per month extra for the back up module
    No info on how much they are charging for this to buy outright


    Cloudy days are really common near Puget Sound eh??

    Tom
  9. begreen

    begreen Mooderator Staff Member

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    In late fall through spring, yes,
  10. Highbeam

    Highbeam Minister of Fire

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    All months except July and August are dominated by clouds, rain, and darkness. The transition months of June and September can be decent or awful depending on the year.
  11. begreen

    begreen Mooderator Staff Member

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    Puget Sound weather can be fickle and there are a lot of microclimates so it's hard to generalize. Our friends up in Concrete see more winter sunshine, but more snow too. They're inland enough to get less effects from the water. Where we live we're fortunate to live in a little banana belt. Our average annual rainfall is half that of Seattle. There was virtually no rain at all here for about 82 days this summer. But go north, up sound 30 miles and you are in the convergence zone where we often see it raining while we are in sunshine. Up toward Sequim, the upper islands, Victoria and Bellingham they get the benefit of being in the rain shadow of the Olympics and see many more sunny days than Seattle. If you're into weather, this is an interesting region.
  12. Highbeam

    Highbeam Minister of Fire

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    I think macmaine was being sarcastic, or at least just poking fun. Generally, weather does suck here. If you're planning an outdoor event, go for august where you almost always have great weather and extremely long daylight hours. The sucky weather is more entertaining than the same ol' thing everyday though and the rain gives us lots of green.

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