Inducing Voltage

Hello I was reading about solar cell systems and it stated that the amount of solar panels is directly related to the amount of electricity you want to produce therewith to produce 12 volts I believe it said that I need 12 panels.
Therewith my question is; Is it not possible to simply induce volatge by adding a step up transformer there eleminitating the need for more solar panels there with in theory able to run more with less. Please help I may be way off here.
Also could that voltage go to a capacitor style electric cell or battery to have the option of running directly from the solar panels or running direct from a battery or electric cell.


  • BB.BB. Super Moderators, Administrators Posts: 28,879 admin
    Re: Inducing Voltage

    I am not quite sure what you are asking...

    Each "solar cell" will produce 0.5 volts---string 36 of these cells in series--then you will get ~18 volts out of a solar panel (enough to charge a 12 volt storage battery).

    But--in the end, this is basic Electricity 101. Power is equal to:

    Power = Voltage * Current

    So, you can have enough voltage to run something, but not enough current. There are electronic circuits that can double the voltage, but they do this by cutting the current in half.

    In other words, there is nothing for free. Your 50lb car battery stores more energy than a 2 oz 9 volt transistor radio battery.

    For solar panels, they have to be large enough to capture enough sunlight that they can convert it into useful work for your application.

    As an example, there are watches now that have small solar cells in them that charge an internal battery to run the LCD display / move the hands. Those are smaller than a postage stamp.

    On the other side, I have a 280 sq foot solar array (~16.7' by 16.7') that generates enough power to run my whole house (~3,000 watts peak or ~13 kWhours per day).

    If you are serious about solar power, you will need to understand some basic electrical theory/math and what you loads/requirements will be. Then it is pretty straight forward to work out how many solar panels, how many batteries, and what support equipment you will need to get your job done.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • westbranchwestbranch Solar Expert Posts: 5,135 ✭✭✭✭
    Re: Inducing Voltage

    Hello Curious and welcome to the NAWS BB site.

    If you have a read over on the other parts of the board you will see the "Beginners Corner". Lots of good questions and plenty of indepth answers there. Good reading...

    I am not sure your first question has ever been asked because I think you have misread whatever is was.

    The statement makes sense if you add the word "volt" between '12' and 'panels' at the end of the second line in your post... then it is true. The more panels you have the more electricity you get, their output is cumulative.

    One '12 volt ' panel will produce a nominal 12 volts, but can yield as high as 17 - 18 volts (VoC).
    Each panel has its own characteristics and the specifications are stated on the panel, usually found on the back.
    Panels also produce Amps and these, multiplied by the volts yields Watts.
    Each panel is rated in Watts of output, specified at a standard temperature, and this is how they are sold to you, X watts per panel @ a reference voltage, they can be 12v, 24v, 36v, etc
    See my signature line for an example of a panel size.

    I will leave the other questions for the more electrically minded members of the board.

    KID #51B  4s 140W to 24V 900Ah C&D AGM
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  • mike95490mike95490 Solar Expert Posts: 8,207 ✭✭✭✭✭
    Re: Inducing Voltage
    Is it not possible to simply induce volatge by adding a step up transformer there eleminitating the need for more solar panels there with in theory able to run more with less.

    Ah, if it was only that easy. Transformers don't work with DC, only AC. There are DC-DC converters, but they are:
    a) expensive
    b) introduce their own losses, requiring more PV panels.

    It's best to acquire panels at the proper voltage for your application.

    As to running more with less, I Wish, but that would violate several laws and
    cause the universe to do something very bad.
    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

    gen: ,

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