Grid Tie vs Battery Bank

Zakarume
Zakarume Solar Expert Posts: 143 ✭✭
in Solar Beginners Corner #1
Hello. I am now thinking about going to a Grid Tie system. No Batteries. I will be using 400 watts of solar and a http://www.amazon.com/iMeshbean%C2%AE-Inverter-Converter-System-22-60v/dp/B005N29SGM/ref=sr_1_3?ie=UTF8&qid=1410840231&sr=8-3&keywords=500+watt+grid+tie+inverter. What is your opinion?
1460 Watts Solar @24v. 675 AH Battery Bank using 12 6v Trojan T-105. 1 Midnite Classic 150. 1500 Watt 24v Samlex Pure Sine Inverter
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Comments

  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #2
    Re: Grid Tie vs Battery Bank

    Basically I think it's criminal to sell those inverters. The can't be UL rated since they create a potential overload on wiring. If your power company finds you using one of these they could shut off your power. A proper grid tied solar array should be done with the knowledge and inspection of your power company. There was one 20 or so years ago with UL rating and it was withdrawn. I think I learned that here, but perhaps on another forum.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,590 admin
    #3
    Re: Grid Tie vs Battery Bank

    As an engineer (and overall cheap person)--My question is always "why do you want to do that?".

    400 Watts solar * 0.77 system eff * 4.5 average hours of sun per day = 1,386 = 1.4 kWH per day (typical yearly average)

    At $0.10 to $0.20 per kWH--That is around $0.14 to $0.28 per day of electricity.

    And, depending on your power meter, your average daytime loads, etc... You could end up saving money, saving less money, or even costing you money (meter turns backwards if energy flow is backwards; meter does not turn backwards; or meter always turns forwards regardless if power flow is backwards or forwards).

    Basically, if your average load during the day is always over 400 watts, then the meter will just slow down.

    If your loads are less than 400 watts during the day, the meter may "error" in the favor of the utility--Or could even "phone home" above possible stolen power (reverse power flow through a digital meter can be logged as a possible theft of power).

    So--Are the the issues above (and the possibility of the Utility pulling your meter as Photowhit said) worth "going guerrilla"?

    -Bill

    If the Amazon page is correct--There is no way the unit is "legal" in North America (would considered a hazard to utility equipment and personnel).
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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