By Cecilia Bremner, Law and Policy Clerk
Agrivoltaics combines food production with energy production. The same land that is used to grow crops to produce food is used to hold solar panels which produce energy. With world population growth expected to reach almost 9.8 billion by 2050 and climate warming expected to exceed the 1.5 degrees Celsius threshold established by the IPCC in the 2030s, there is a real and immediate threat that both the global food and energy systems will collapse, and soon! These systems are already struggling with about 45 million people near starvation and 1.1 billion people without access to electricity. Agrivoltaics is a potential solution to both the food and the energy crisis.
Agriculture is highly resource intensive process relied on to feed the global population. About 38 percent of the world’s land surface, or five billion hectares, is used for agriculture. Irrigation of agriculture constitutes about 85 percent of global water consumption. Agriculture also contributes over a third of global greenhouse gas(GHG) emissions and accelerates biodiversity loss. National Geographic has proposed five steps to feed the growing population while accommodating the climate crisis—all five of which boil down to making agricultural practices more sustainable.
At the same time, electricity generation also needs to become more sustainable. This includes efficient use of land for renewables, like solar which requires a significant amount of land with similar characteristics to land that is also appropriate for agriculture.
Rather than competing for the limited resource of land, solar panels and crops can be placed together for more efficient land use. Currently, the major challenge to combining agriculture and solar is that the ground beneath solar panels is not usually suitable for agricultural purposes. Dual use is the only current exception whereby traditional solar parks are used for beekeeping and for grazing small livestock, such as sheep and chickens, which help to maintain the vegetation beneath the panels. Otherwise, panels are too close together for modern farming equipment to maneuver and they provide too much shade for effective crop yields.
These challenges have solutions. The three basic agrivoltaic setups are currently: 1) solar arrays spaced for crops, 2) solar arrays tilted above crops, and 3) greenhouse solar arrays. These setups increase distance between the panels and adjust the height of the panels to allow different machinery and potentially larger grazing livestock to pass through. Additionally, these setups adjust the transparency and angle of the panels to ensure an efficient amount of light passes through to the crops below the panels.
Studies suggest that combining crops and solar panels actually improves the conditions for both the crops and the panels. Regarding crops, too little light and their ability to photosynthesize and grow is limited. Too much light and the crops can no longer absorb energy and instead evaporate water to get rid of the excess energy; this threshold is called the light saturation point. Regarding solar panels, too high a temperature can decrease their efficiency. When crops and panels are used together, systems have shown a 30 percent improvement with the use of shade-tolerant crops. Additionally, summer crops seem to thrive in the favorable microclimate created with heat and water flow controls. The shade from the panels reduced crop evaporation overall such that they required less watering. The crops were also irrigated by the residual water from cleaning the panels ensuring this water served another purpose. Any evaporation from the crops created a cooling effect for the panels which increased their efficiency. The crops were also protected from the elements allowing them to be sold even after weather that might otherwise have rendered them unfit for the market. Thus, solar panels provide a shady and protective canopy for the crops while the crops help to keep the panels cool and efficient. The benefits of this canopy extend to the workers cultivating and maintaining the crops who are also kept cool and sheltered.
Despite these significant benefits, agrivoltaics do pose some challenges. Because of the shade created by the panels, really only shade-tolerant crops are suitable. The installation costs of panels higher off the ground, especially those with the ability to adjust the panel angle, are also likely to be higher than traditional solar installations. Crop yields may be marginally lower than if the land was purely dedicated to agriculture. The amount of energy generated will also probably be lower than a traditional solar farm as there are fewer panels for the same area. Additionally, farming machinery will need adaptations to protect the panels from damage.
These challenges can be overcome. A recent study by Oregon State University estimated that converting even just 1 percent of America’s existing farmland to agrivoltaics could have significant beneficial impacts such as meeting national renewable energy targets, saving water, and improving future food system reliability. While the upfront investment for such conversion will be significant, Oregon State University’s Vegetable Research Farm estimates that an investment of $1.12 trillion over 35 years will be paid back in just 17 years through the green electricity produced by these systems. Such a conversion to agrivoltaics could also create a much-needed revenue stream for farmers who increased their bankruptcy filings by 23 percent in the past year. Agrivoltaics allows everyone to win.
Agrivoltaics is a realistic option to help stabilize food supplies and decarbonize electricity grids. Both are imperative for our survival. So, let’s embrace agrivoltaics and take a positive step towards our climate resilient future.
The blogs posted on Charged Debate reflect the writers' opinions in their individual capacities, and do not necessarily reflect the perspective of the Green Energy Institute, Lewis & Clark Law School, Lewis & Clark College, or the writers’ past, present or future employers or other associations. Any information in any blog on Charged Debate is meant purely for general educational purposes, does not constitute legal advice and should not be relied upon for any purpose. No representations or warranties, express or implied, are made with respect to any content in any blog posted on Charged Debate.
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