how to use excess energy

cizzi Solar Expert Posts: 109 ✭✭✭✭
I have a small system for those of you who know me.. 106AH battery and 80W panel with a 15A prostar charge controller.. i want to know if its possible to use the excess energy thats otherwise being dissipated as heat using my existing charge controller? or what small cost item can I buy to make use of this wasted energy.. the system is typically at 100% by early morning since I use very little power (only a few lights at night).. any help would be nice..



  • n3qik
    n3qik Solar Expert Posts: 741 ✭✭
    Re: how to use excess energy

    Look at this, it is a programmable voltage controlled switch.

    NAWS has a PC board that does the same thing:

    Just be careful, if you go this route. If you set it up to use 90-100% of the extra power. On cloudy days you could end up not charging the battery completely.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: how to use excess energy

    "the excess energy thats otherwise being dissipated as heat"

    this statement is false as the prostar is a series controller and not a shunt controller. what that means is that the pvs are switched out of the circuit for an open circuit and not to ground so the only power dissipated is what is needed to operate the controller, which for 12v is 22ma.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: how to use excess energy

    Some Bluesky controllers (and I'm sure others) have a secondary load control ciruit that you can use to charge another battery bank, or run a secondary load such as a pump, or water heater or what ever. The primary battery bank gets priority, and then the secondary circuit gets what's left. Better for adding ahs to a second battery than powering a big load.

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: how to use excess energy

    As stated in other posts here, you can use the 'lost' energy to power small chargers ( cell phone, flashlights, etc) but usage would be manually controlled. You have not stated whet your current loads are? Perhaps you could use more at night as you seem to have enough PV for current use plus...
    Also just add a second battery in parallel to store more to satisfy the '3 day rule of thumb'...

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  • _OS_
    _OS_ Solar Expert Posts: 207 ✭✭✭
    Re: how to use excess energy


    You might learn something from this blog:
    System Automation for a Spare Battery Bank