Don't know exactly where a motorized roll-up kit can be purchased but it is a trend in greenhouse ventilation to have a thermostatically controlled roll-up system. I use an 18V cordless drill to roll sides up on my greenhouses but I only roll them down in spring and fall (or when a strong storm is pending in summer).

If you contact PennState Seed Co. Ray Witmer can either sell you a kit or direct you to the proper source.

Rita - I just got a new Farm Tek catalog and it has many different solutions for roll up sides or drop down curtains! The example you mention was an article in Growing For Market...I'm not at home, so can't tell you which edition, but I bet they'd mail you the article if you contacted them. Most greenhouse/hoophouse companies tend to offer solutions for rollup sides. You might also try the high tunnel list serve out of KSU.

Here is a link that might be useful: High Tunnel List