Then put up a simple ground mount nearby (upwind) and get a better angle (about 37 degrees is best in S WI across N IA) for better year around production.

And the fact the REC only pays a fraction going back as they are charging is really not that important for a large electricity user like a hog barn.  Don't worry about selling the excess back, just focus on your own useage. Reduce your own bill. Look at your electricity useage (kwhr used on your bill) you can offset at least a part of that.

Avoiding paying 12 cents/kwhr is a payback too.  The times when the sun is out and its hot in the summer are also the times when you probably have your peak demand due to fans, etc.

My REC has a large almost $40./mo meter charge which pays for the office, repair crews, wires and transformers. They do an excellent job of maintenance. I'm happy to pay their meter charge, they don't bury these expenses in the kwhr charge as many utilities do to keep the meter charge artificially low. Other users are not "subsidizing" solar panels when the meter and facilities charges are set correctly. 

The price of wholesale electricity the REC buys in the summer goes up with demand. It makes sense for them to purchase any excess kwhrs available from their customers. In fact our REC just opened up its own second large solar farm. Most utilities have a maximum size of individual solar panel arrays they allow to connect to their system, and for good reason. For a private home here it is 20 kw peak. I believe for a business it is higher.

In fact we do need a variety of different power sources, distributed around the countryside. But there is no reason a large user of power like a hog barn shouldn't generate at least part of it's own electrical needs.  The payback is there on avoided purchased kwhrs.

Here's a picture of a very cost effective 24 panel ground mount my son in law and I put up. You do need an agreement with the utility and a licensed electrician to do the hook up and sign off on the installation. It has a very good ROI, even in the winter when my heated cattle waterers are using a lot of kwhr. Providing I broom the snow off of them! Gary, we learned a bit about concrete work on this project - there is a lot of concrete holding those pipes in place.

A good source of info and system prices

(IMG004 Ground mount array.jpg)

IMG004 Ground mount array.jpg (104KB - 203 downloads)