Convert unused power into hot water?!

aleman83aleman83 Registered Users Posts: 24
Hello everybody,

I have had my off grid system running for a few months now and I am very happy with it. I have three 315Watt panels in series running over a Midnite Solar light 200 Charge controller. On sunny days I have produced up to 4 Kwh, but I am only using between 1 and 2 Kwh. Now I was wondering.... Is there a way to divert the unused power from the midnight solar classic light and use it to heat water? My controller usually goes on absorb at 10am, and will only put through 20A of the 60A that I get around noon. If I could divert that extra power and then use it to make myself some hot water for the shower that would be just perfect solution!

Looking forward to your opinions!

Have a great Christmas everybody,



  • PhotowhitPhotowhit Solar Expert Posts: 5,011 ✭✭✭✭
    Re: Convert unused power into hot water?!

    Yes and no, you can use the Aux funtion to start a water heater, but most use more power than you are producing, so it is likely to put your charge current needed to a higher amount and the Aux will shut it down. There are some threads here and at the Midnite forum on the topic.

    I'm only just getting to the point of being serious about this, and will look forward to others ideas.

    Something is hinky with your math "...will only put through 20A of the 60A that I get around noon..."

    You have 3 - 315watt panels or 945 watts so a potential at 24volts of 945/24 or about 39 amps, just befor you drop down to float you have a potential of 945/28 or 34 Amps and a bit more in float, typically you should produce about 75-80% of these numbers. Usually people wait until they reach float to run opportunity loads...

    Sorry I'm an idiot and was thinking 24 volt system (my system) but I'll leave the math it should be about right for a 12 volt system like yours. I got to lay off the eggnog!
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do
  • bill and rosabill and rosa Solar Expert Posts: 26
    Re: Convert unused power into hot water?! is midnight solars forum. You might find what you are looking for here. is the hot water topic
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