High tunnel orientation
I just bought a high tunnel and am trying to decide how to orient it. I live just south of the 40th parallel near Decatur, Illinois on the open prairie with no windbreaks. There is a fairly large shop about 200 feet north of where I plan to put the tunnel but I don't think it will shield it from the winter wind.
Macon County Illinois
A high tunnel should be oriented in a direction that is perpendicular to the prevailing winds on your farm. In Illinois, our winds are predominantly from the south-southwest.
So, perhaps placing your high tunnel southwest to northeast might make more sense (to reduce surface area exposed to potential wind damage). Wind damage might be your biggest concern. As you know, placed out in the open high tunnels are highly vulnerable. A colleague in Western Illinois shared that he knew of one producer who lost his tunnel twice due to wind. You might consider a double cover to help reduce wind damage.
I also took the liberty of contacting another colleague, Duane Friend, Energy and Environmental Stewardship Educator (and who teaches meteorology at Lincoln Land Community College). He shared a wind rose climatology station graph that I would be glad to send to you (please email me at firstname.lastname@example.org) Also, check out this url for some excellent information http://hightunnels.org/orientation-structural-considerations/ Please feel free to contact me with any additional questions. I would also suggest that you contact your Local Food Systems and Small Farms Educator, Doug Gucker at email@example.com.