Time to upgrade the solar heat sink

You can see a pretty clear "before" and "after" since I changed the fans from 12 vdc supplied by a transformer and 120vac to solar pv on May 1st. Their are two ways to hook up the solar pv, which in my case is a 60 watt panel. One supplies about 21.4 volts and the other about half of that. The 21.4 option is really for a 12 volt system with a charge controller that keeps it around 12 volts. So as to not burn out the existing fans, I ran them at half of the 21.4 option, nominally a 6 volt system. So they run slower. And they don't run at all at night.

Confused? Me too. But the outcome is clear: a low of 45 degrees at night and a high of about 92 during the day. Death Valley like temps, probably not optimal for veggies. Hope the buds didn't die.

So today I ordered a charge controller that will keep things at about 13 volts. Also, I will buy an automotive 12 vdc battery so the fan can run at night and keep things a bit warmer. Hopefully this will lower the highs and raise the lows. Tonight, however, I am going to add two more fans. As it is only the beginning of May with these highs in the lower 90's, I am going to need more ventilation so as to keep it from getting really hot.