I had the opportunity to visit Ag Progress Days at Penn State this August and peruse the wide array of machinery associated with agricultural enterprises and see what educational venues and tours were offered. In the days when I was an active participant in the educational program at Ag Progress Days, especially conducting tours of our Penn State High Tunnel Research and Education Facility at the Horticultural Farm, we did demonstrations highlighting our plastic burner (which could fit into a boiler to create hot water or steam depending on the boiler unit). It burned the plastic at 2,000º F so there were no toxic emissions. The demonstration was a big hit with growers and highlighted the huge problem of not only disposing of ag plastic waste but consumer waste too – but it never gained traction to take it to further commercialization. Plastics are a derivative of petroleum and still have the energy value of petroleum trapped inside, waiting to be released. Plastic is not a waste but a valuable resource waiting to be used to generate energy and should not be destined for the landfill.
When I think how far we’ve come on energy utilization on the farm from the days of actual horsepower-driven implements and brute human strength to tractors propelled by petroleum and electric power (now generated by coal, nuclear power, natural gas and in some cases wind and solar) it is truly amazing. The current push toward wind-, solar- and battery-operated vehicles makes me wonder about the future of agricultural energy. A few years back we were energy independent and the cost of fuel was much lower. Can we think that raising the price of fuel will cause farmers to switch to battery-operated farm vehicles? I believe that changes will come naturally as industry invents new technology that is market driven and battery-operated farm and commercial vehicles may indeed move forward.
Our food system depends on reliable energy to function and mandating changes from on high could cause tremendous damage to the system. Disrupt the food system and now you have a real problem on your hands. Energy inputs are critical to the food system functioning and I can see opportunities for more renewable energy in the future. One area that has recently caught my attention is the field of agrivoltaics/agrisolar (AV/AS). I had some interesting conversations at Ag Progress Days on this subject with industry folks that are involved in marketing these systems and also recently listened to a webinar sponsored by the American Society for Horticultural Science and the Commercial Horticulture Professional Interest Group on this subject. The speaker was Dr. Matthew Kleinhenz, professor and Extension vegetable specialist at Ohio State University. The goals of Matt’s presentation were to further inform participants about AV/AS and help position them to recognize, appreciate and pursue AV-related opportunities. This was accomplished through summaries of the literature, factors governing the design and operation of solar farms and integration of horticultural activity with them and ongoing work in Australia, where Matt is currently on a Fulbright Scholarship researching this topic.
What I learned is that “solar farms” are in most cases large undertakings by companies that choose a site and install solar arrays that may be either elevated overhead or in-row systems; the arrays may be either stationary or track the movement of the sun. Solar farms have fencing around them and there is a good amount of maintenance of the systems. The ground underneath the systems needs to be maintained and is a considerable expense. This is where horticulturists or agronomists come into the picture. Matt showed pictures of a grain combine working under an elevated system, another shot of an in-row system with a mowed lawn area and another with wildflowers. Sheep, chicken and bee operations are associated with solar farms.
One concern is dust on the solar arrays, so that’s something to ponder when thinking about a viable ag operation. There seem to be a lot of opportunities to develop other potential enterprises such as vegetables, small fruits, tree fruits, grapes, floriculture crops – and even agritourism. One must keep in mind that producing energy is the main priority of the systems. There are many factors that need to be considered, such as the height of the arrays and width of the rows of panels. Consider the weather, especially adverse weather events. Currently, the number one concern of the companies erecting solar farms is producing the most energy on the given plot of land, not producing a crop for sale.
Another note: Solar panels shed rain like parking lots, so dealing with this issue must be taken into consideration. There could be an opportunity to capture that water and use it for irrigation or divert it to another operation outside the boundary of the solar farm. It seems that solar farms are starting to view the total revenue from a site instead of splitting revenue between the energy side and the agricultural side. There are many facets to solar farming, and in the past companies have been coming to the farmer or landowner and wanting to put a solar farm on the land. Maybe in the future farmers will want to approach energy companies to install a solar farm that can supply them with energy and incorporate agriculture.
As I reflect on field of agrivoltaics/agrisolar I’m reminded of research I did at Kansas State University in cooperation with the foresters in agroforestry. We grew agronomic crops and vegetable crops utilizing plastic mulch and drip irrigation between rows of black walnut trees to generate a cash flow in the early years of the tree plantation. The trees continued to grow, shrinking the space for crops – whereas solar arrays are a set size and distance apart. I look forward to continuing to monitor developments in this field.
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