Many farmers have installed solar photovoltaic panels on their properties and have begun generating their own electricity. Solar photovoltaic systems are generally very low maintenance, says Daniel Ciolkosz, Penn State Extension, Department of Agricultural & Biological Engineering. So, if you are thinking that a solar photovoltaic system might be in your future, here are some things to consider:
Where would you put it? The ideal location for a stationary photovoltaic array is a south-facing surface that is tilted at an angle equal to the latitude of your location (in Pennsylvania, that's about 40 degrees up from horizontal). However, you don't have to have the perfect slope or orientation to get good performance. For example, if you have a barn roof that faces within about 20 degrees of south, and has a bit of slope on it, you'll probably be fine using that roof as a location for a photovoltaic array.
Will it stay in place? 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.
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. 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.
Can you afford it? The payoff for solar photovoltaic electricity depends on the future price of electricity as well as alternative energy credits. Both of these are highly uncertain. Regardless, 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 photovoltaic systems.
Click here to listen to a recording of a Penn State Technology Tuesdays webinar on solar energy.
Source: August 2011 Penn State Extension Dairy Focus Newsletter