Invertors and heat

I have recently installed a fronius 3kw invertor matched with about 3kw PV at my Arizona home. The fronius invertor is supposed to back off power production once the temperature reaches 104 degrees. Already getting close to 100 degrees (high) in the 6 foot X 8 foot room without the invertor running and is up to 109 degrees outdoors.

Q1. Does anyone know how much the heat the fronius actually puts out while it is inverting? I am sure it is related to the amount of energy fed from the PV array. I am getting ready to commission the system and will not be around to monitor during the summer. Anyone have any solid numbers around this?

Q2. I have an AC vent in the invertor room and could easily cool the room. Does it make sense to cool the room (which takes more power for the central AC)and take full advantage of the grid-tie system, or should I just let the room get hot and allow the fronius to back off production during the heat and save a little on the AC bill. My gut tells me to cool the room, but any input from the experts would be appreciated.

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Invertors and heat

    GT inverters are around 95-98% efficient.

    3,000 Watts * 0.05 losses = 150 Watts of heat
    3,000 Watts * 0.02 losses = 60 Watts of heat

    You can also try simply pointing a desk fan at the inverter--That should reduce the temperature rise quite a bit.

    It does cost you some money to remove the waste heat... 150 watts is around 512 BTU/Hour of cooling. Significant, but probably not a huge part of your typical AC load.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SkiDoo55
    SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    Re: Invertors and heat

    Fronius should have a temp vs output chart to look at. Also, keep in mind that high heatsink temperatures decrease the life of the internal electronics.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!