What a "cool" opportunity load... :)

RandomJoeRandomJoe Solar Expert Posts: 472 ✭✭✭
I mentioned before I finally got the off-grid / backup subpanel tied in to several circuits in the house. That put the subpanel next to a mini-split I had installed for my "server room" back when I used to run lots of high-temp computers. Haven't used it in quite some time, and was even going to remove it when I painted the room a few months back...

Of course I realized then I had a perfect opportunity load for my solar panels! I'm usually floating by 1PM, with several hours of prime solar hours ahead. Since I am now on the "peak demand" plan with the power company I don't run the main house AC from 2-7PM. So I wired the spare circuit breaker to the mini-split.

The mini-split is nothing special - a 9000 BTU basic model, not inverter type. Runs like a dream on the inverter. I did get a bit of a thrill when the Mate captured a wattage reading on the inrush, something over 5,000W! Otherwise, between my always-on afternoon loads and the AC I'm drawing 1300-1400W (fridge cycling on/off) with it running.

Had all kinds of fun testing it out last week, every time I tried running it the clouds moved in! But today is clear and sunny. Got home around 1PM and turned it on, been running ever since - just now, at 5:30PM, the input watts are finally falling below output and my office is a brisk 68 degrees! :D The rest of the house is staying considerably cooler too, it's usually nearing 80 by now but still just 76.

Now I just need to wire up a relay, hook it to the automation system, and add some programming to fire it up after the system floats.

I've also been rereading the inverter AC thread with renewed interest! ;)

Almost 9 kWh produced from a 2kW STC array so far. Still a couple more (waning) hours of sun to go.


  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: What a "cool" opportunity load... :)

    Awesome! That's a great situation to be able to take advantage of!
  • westbranchwestbranch Solar Expert Posts: 5,142 ✭✭✭✭
    Re: What a "cool" opportunity load... :)

    you could also turn the furnace fan on manually to spread the 'cool' around the house too.
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Ralph DayRalph Day Solar Expert Posts: 886 ✭✭✭✭
    Re: What a "cool" opportunity load... :)

    Don't forget, it isn't just floating when you've got unused energy. Depending on how long your system absorbs you can start some opportunity loads while in absorb. I do that with my water distiller and MX60 relayed outlet. Not right at the beginning of absorb, but after an hour or so a 1000watt load can be carried (an hour before float and some number of watt hours salvaged|).

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