There are few things as embarrassing as having your solar panel blow away in the wind, or worse yet, having the weight of the panels squash your barn. Most solar panels are surprisingly light, so little or no structural stiffening is needed to make most barns “solar-ready". However, if your building is on the rickety side, you should have it checked by a qualified engineer. Most installers are experienced with using good quality mounting hardware that not only holds the panels down, but prevents roof leaks as well.
3. What about the wiring?
The electricity generated by a photovoltaic panel is "Direct Current" (DC). You need to change it to "Alternating Current" (AC) with a device called an "Inverter" before it can be fed into your farm's power system. (Footnote: a few folks use the DC power directly rather than switching it to AC, but that is not really common in Pennsylvania). You will need a spot on your farm to install this equipment, preferably close to your solar panels and near the main distribution panel for your farm's electrical system. Some inverters can be installed outdoors, but it is always nice if they can be kept under cover. Safety shutoff switches and lightning protection are also essential elements of the overall system.
4. Can you afford it?
The payoff for solar PV electricity depends on the future price of electricity as well as alternative energy credits. Both of these are highly uncertain. Right now, the credit market is taking a beating in Pennsylvania, but it is sure to rebound. However, nobody really knows what the long term value of those credits will be. Regardless, you should take a close look at the financial side of things and be absolutely certain that, if there is a bad year or two in the credit market, you will be able to get by.
Finally, be sure to talk to people - check with more than one installer, and talk to as many farmers in the area that you can find who have already installed solar PV. That will probably give you the best idea of whether or not a solar power system would make sense for your farm.
----- Daniel Ciolkosz, Penn State Extension, Department of Agricultural & Biological Engineering University Park, PA