My first thought about the 90vdc motor from Grainger was to use a varible speed controller, but then most of those have a low voltage cut out of around 20 volts. I geuss the only true solution would be to add more PV modules. To think that I could find a 12vdc motor that would run such a large whole house fan effectively on less than 10 amps dc was a pipe dream.
You see the PV array at 1,000 watts a 12 vdc nominal will only produce a daily equivalent of about 300 amp hours. Typically we "spend" about 200 amp hours a night as is. Maybe a more efficient ac motor would be easier to find?
