Thanks Troppo! I'm happy to help you, but trust you have electronic skills? From the photos, you can see I used a Jaycar temperature switch kit which I modified somewhat, and 4 x small low current computer fans, all of which were powered by the solar panel itself. It's a tricky design, as the panel's output varies from 60+ V to 0V depending on sunlight! It works fine although there is a "grey" zone at a certain low- sun period whereby the controller runs out of drive & does strange things!Nothing serious ,but if would be neater if the control circuitry was powered separately eg. from a rechargeable battery arrangement.
Anyway. I will send you the ccts. parts etc.soon. after I draw it out neatly, as it's a bit of a dogs brekkie at present.
The solar panel kit is the Oatley Electronics one which Silicon Chip mag. reviewed not long ago: it's a beauty, & cheap. Alan