Grid Tie Inverter? Anyone got one?

Discussion in 'Energy & Electricity' started by youpock, Nov 2, 2009.

  1. youpock

    youpock Well-Known Member

    Does anyone have experience with these?

    New stackable MASSPOWER Grid Tie Inverter 250W - eBay (item 320442946729 end time Nov-03-09 10:39:57 PST)

    I'm thinking about running a few cheap solar panels to a few little batteries with one or two of these tied back in to cut back on electricity costs, also I want to be able to in a time of need hook up an inverter for standing power. What I'm wondering about is the ebay auction says to not run batteries but instead to run it directly from the panels. Just wondering if anyone has experience with them because I'd like to run batteries. Here's a vid of it from youtube:

  2. northernontario

    northernontario Well-Known Member

    The thing with grid-tie is... you can't just plug it into the wall (or wire to the main breaker box) and expect to start earning money (or atleast saving money) on your Hydro bill. The hydro regulator has rules regarding this sort of stuff.

    The reason to not run batteries is that if the sun isn't out charging your batteries... the grid-tie will pull power from your batteries, draining them.

    A grid-tie system is not a "DIY,thrown together on a weekend" sort of system... and the guy working the hydro line up the road who thinks the power is cut may not appreciate you back-feeding power into the grid. (Same applies to hooking up a generator to run power into your primary household wiring when the power is out... but not killing the main breaker in your house to prevent backflow out the lines)

  3. bunkerbob

    bunkerbob Supporting Member

    I'm sorry but I have to disagree with the statement about drawing power from batteries to feed grid. I've been grid-tied with battery back-up and-off grid both, the grid-tied inverter will only sell when you are producing an excess, more that you can use. You can set the parameters for selling with almost every inverter to avoid draining batteries.

    The grid-tied inverter when installed correctly will separate itself from the grid in the event of a grid power outage automatically. Then when sensing grid voltage reconnect.
  4. bunkerbob

    bunkerbob Supporting Member


    I've been a long time reader of Home Power magazine, great info in print and online...Home Power Magazine: Solar | Wind | Water | Design | Build they will send you a sample copy.

    You can see some of what I have done...bunkerbob
  5. youpock

    youpock Well-Known Member

    hmm those ebay ones that I linked initially are super illegal in the USA.. lol
  6. dahur

    dahur Well-Known Member

    Well, Senate Bill 233 just passed. As soon as Gov. Richardson signs it, it'll be law here in New Mexico.
    Our tax accessor won't get the chance to jack our property tax. System cost will be exempt from the tax, just like in about 26 other states.

    So. The system I'm looking at, and have gotten a quote for, is a ground mounted 4.3 kw, using micro inverters from enPhase.
    Seems to me there are a lot more pros than cons using micro-inverters.

    I've been waiting for this, and am looking forward to it getting it done.

    Now to find out if my homeowners insurance is going up.
    Last edited: Feb 27, 2010
  7. JeepHammer

    JeepHammer Well-Known Member

    I have a 'Sunny Boy' grid intertie inverter that I run with panels.

    Home.SMA America, LLC

    I make power in the daytime, and what the house doesn't use, turns my meter backwards for 'Credit' with the electric company.

    I can use that credit up at night when the panels aren't producing, or when it's overcast and the panels aren't producing.

    I don't use battery back up since I'm in town with this system and have grid access.
    My electric bills are usually the minimum amount in the spring/summer/fall months (around $12 to be tied to the grid a month).


    I have a 'Farm' house in the river bottoms, pretty far from electrical hookup, and the local electrical company wanted $125,000 to run the lines to the cabin/house/barn.

    I went full on self sufficient there,
    Panels, Wind, Generator for the heavy duty loads.

    Since there are three sources, That is considered a 'Grid', and went with Outback inverters and a battery bank for night/overcast supply for small loads, like water well pump, house lighting, ect.

    I went with 'Outback' inverters for that application since they support higher loads and work with multiple source grids easier.

    OutBack Power / Home

    Batteries are HORRIBLY inefficient way to store energy.
    A battery will shed 85% or more of your production in the form of heat, off gassing, chemical losses, ect.
    So using huge battery banks isn't the best way to go about storage,
    But if you limit your USAGE at night, they work silently and will produce enough current for you to use lights, small load appliances without busting the bank.

    Batteries cost a bunch to acquire,
    Are dangerous to work with,
    They require constant maintinance,
    And have relatively short life spans.

    Passive solar homes, with good insulation are money in the bank.
    Shading in summer to reduce Air Conditioning costs,
    And good wind brakes in winter,
    Combined with good insulation,
    Lots of passive solar features so the heat bill doesn't drive you into the poorhouse will do more for you,
    And CONTINUOUSLY pay you back,
    Will beat any cost reduction you will get from panels.

    Panels, either PV or Thermal (hot water, home heating), will pay you back continuously with very little maintinance.

    Wind takes maintinance.

    Batteries take a LOT of maintinance, nearly constant maintinance, and they are for the 'Luxury' of night lighting and plug in appliances at night.

    If you decide to run even a small battery bank (up to about 12 or 14, 6 volt batteries),
    Consider a small wind generator even if you don't have enough wind for the 'Experts' to say it's worth fooling with...

    I use 6 volt golf cart batteries an a converted S-10 pickup to get around town with on short trips.
    Spends most of it's time plugged into the garage.

    The solar panels charge only when the truck is plugged in,
    But the wind generator puts out a small charge, and 'Tops Off' batteries very nicely!
    It's called a 'Finish Charge' and small wind is PERFECT for that purpose even in areas that don't get a lot of wind.