I’ve always wondered how much space it would take up if we powered the world with solar energy, and if there would be enough land left over for us to use for other purposes. Obviously, each solar panel takes up space (particularly around 16 or more square feet)! If you are like me and wonder about how we will optimize land usage in the future to accommodate the rapidly growing population, you might wonder if land underneath solar panels would still be usable for other purposes, or if we would need to set aside large areas of land specifically for energy production. The latter might seem unsustainable, especially as Earth’s population and the demand for space increases rapidly.
I was happy to come across an article that discusses the benefits of having solar panels above certain plots of land that can actually improve the conditions underneath them. One way this can be done is through agrivoltaics. Agrivoltaics is the simultaneous “use of land for both agriculture and solar photovoltaic energy generation”. This strategy has a lot of potential due to the mutualisms that can occur between the crops and the solar panels.
In agrivoltaics, solar panels are placed above the land, providing shade to the vegetation underneath. This can be useful for reducing water usage in irrigation because plants have a light saturation point, or a threshold in which more sunlight does not benefit the plant’s growth in any way. If solar panels are strategically placed at angles that allow some sunlight to hit the plants, then this threshold can be met in a controlled way and less water can be used. Additionally, the solar panels can be used for providing livestock and other farm animals with shade on hot summer days. By cooling off the farms, the health and productivity of the farm can be enhanced.
The plants also help increase the productivity of the solar panels. By having plants underneath solar panels, the solar panels are cooled, which is estimated to increase their productivity by up to ten percent! Agrivoltaics also serves as a source of additional income for farms, as excess energy produced by the farm can be sold to the grid through net metering. Overall, agrivoltaics has the potential to increase farm health and productivity while producing clean energy and a steady stream of additional income for farmers.
While agrivoltaics is a promising strategy for implementing clean energy solutions, it is necessary to also assess and acknowledge its cons before it is implemented. Firstly, with all solar energy, it requires more land per unit power than fossil fuels. In other words, more land will be taken up by solar panels than that needed to provide the same amount of energy using different non-renewable energy sources. However, this concern can be addressed by the fact that agrivoltaics involves integrating the use of solar panels in already existing farmland. So, instead of taking up more space to install the solar panels, existing farmland will build them above their land, simultaneously increasing crop yield and income. Another major hurdle in implementing agrivoltaics is its price. Agriculture uses about 21% of the total food production energy, which is around 615,000 gigawatts. For reference, a standard 36-inch by 65-inch solar panel produces about 300 watts per hour on a sunny day. If we assume that each one of these panels costs around $140 dollars, and that they will be exposed to around 5 full hours of sunlight per day, then it can be estimated that each solar panel will produce approximately 547.5 kilowatts of electricity per year. Therefore, to fully support US agriculture using solar panels, we will need about 1.1 billion solar panels. This would cost around 157 billion US dollars!
So, this information begs the question: Should agrivoltaics be implemented on a large scale, and is it realistic to do this?
An Ohio State University Study found that if 1% of US farmland was converted to agrivoltaics, then it would be enough to meet US renewable energy targets while simultaneously saving water and providing more income for family-run farms, which have been facing economic hardships. This conversion would cost about 1% of the federal budget; however, it is predicted that this would be paid off by savings from agrivoltaics just 14 years after. So, even converting a small portion of the farmland will bring us a big step forward in fighting the climate crisis, while also eventually saving money. It is up to the future generations to ensure that we are implementing sustainable solutions to the climate crisis and a rapidly growing population, and agrivoltaics has the potential to be one of these solutions.
About the Author
Alec Pirone is a third-year undergraduate student at Princeton University studying environmental engineering with a minor in applied and computational mathematics. He co-leads the Princeton team of RE-volv Solar Ambassadors. Outside of academics, he is a member of Princeton’s Swim and Dive Team and works as an environmental research assistant.
