Agrivoltaics: how solar and farmland can fight climate change
Agriculture is one of the key foundations for society. But right now, farms are on the front lines against the climate crisis. Some of the biggest threats to the agricultural industry right now are droughts and changing temperatures, which are directly linked to climate change.
To make it out alive, the agricultural sector has to figure out how to mitigate against the problems we're already experiencing because of climate change - like droughts and changing temperatures.
Not only that, the agriculture industry needs to figure out how to stop contributing to climate change as well, so that they can hopefully prevent the effects from being even worse. Farming is extremely energy-intensive and has created about one-third of greenhouse gas emissions and accounts for 85% of global water consumption.
Agrivoltaics could provide the solution that farms are looking for. By pairing solar panels with farmland, farmers can save money, increase productivity, and take advantage of clean, renewable energy. In this article, we're going to take a closer look at what agrivoltaics is, how it works, and why it's important that we take this dynamic solution seriously.
On this page
- What is agrivoltaics?
- Why would farms choose agrivoltaics?
- Impacts of agrivoltaics
- Examples of agrivoltaics systems
- Solar vs. farmland: why not have both?
What is agrivoltaics?
Agrivoltaics, also called solar sharing, is using the same land for both agricultural and solar development.
A typical agrivoltaic solar system consists of ground-mounted solar arrays with crops planted either beneath or between the rows of solar panels. The panels can be installed on mounts that are tall enough to let farming equipment pass below.
At first, it might not seem like it makes sense to plant crops beneath solar panels. After all, don't plants need light to survive?
Of course, plants need sunlight for photosynthesis. But many crops don't need as much sun as you think. In fact, too much sun can be a bad thing. Agrivoltaic systems can be designed to let the optimal amount of light reach crops so they can grow, without allowing too much light to get through and cause the plants stress.
Why would farms choose agrivoltaics?
Agrivoltaics have a wide range of benefits for farmers, both immediate and long-term. Let’s dive into some of the reasons why a farmer might choose to install solar panels on their land.
Lowers electricity costs
The main appeal of solar panels, whether it be for your home or a farm, is lower electricity bills. Solar panels turn sunlight into electricity that the farm can use to operate, instead of having to take electricity from their utility. By taking less electricity from the utility, a farm's utility bills could decrease, or be completely eliminated!
One of the easiest ways to cut farming costs is by bringing down electricity costs. For the average farm, electricity accounts for between 1% and 6% of the total operating costs. Installing solar is an investment that brings immediate savings.
For family-owned farms, immediate savings are more important than ever. In 2019, the United States saw a 20% increase in the number of bankruptcy filings claimed by family-owned farms. So, by investing in an agrivoltaic system, these small farms can have a little extra wiggle room in their wallet.
Decrease water use
It's clear that installing solar panels would save money on electricity, but an agrivoltaic system can also cut down on water usage. This will not only cut down on overhead costs but also helps farms conserve water as the resource becomes scarce.
All plants have what is called a 'light saturation point'. This is the point at which sunlight hitting a plant is no longer helping it grow, but instead increases stress and water demand. By designing an agrivoltaic system, you can prevent crops from crossing their light saturation threshold and becoming stressed.
The low-stress environment created beneath the solar panels decreases the plants' need for more water. The shade of the photovoltaic panels also prevents water from evaporating from the soil. This means that the plants will need less water, and there will be more water retained in the soil, so farmers don't have to irrigate as often.
Increased crop production
Installing photovoltaic panels above plants makes farmland 70% more productive. With the same amount of sunlight, agrivoltaic farms can produce two products: crops and electricity.
Some crops produce better under solar panels than they do in conventional settings. Plants like lettuce, chard, spinach, peppers, and carrots, are all food crops that benefit from being shaded.
In a study conducted by the University of Arizona at their Biosphere 2 research center, tomato plants in agrivoltaic systems produced double the amount of fruit of those in a control group without solar panels. Other crops, such as lettuce and jalapenos, yielded the same amount of fruit but used substantially less water to do so. One study in Japan found that corn planted under PV panels outperformed traditionally grown corn by over 5%.
Increased crop production puts more money into the pockets of farmers. But it also puts more food on the table for everyone. With the global population skyrocketing, we're going to need to ramp up agricultural production. With limited arable land available to expand farming, we have to figure out other ways to increase the amount of food we produce - and agrivoltaics could be one way to do just that.
It's important to note that not all crops will thrive under solar panels. Wheat, for example, would not be suitable for an agrivoltaic system, as it requires a substantial amount of sunlight and is difficult to harvest beneath solar panels.
Increased solar power generation
Agrivoltaics doesn't just lead to an increase in crop production - it also increases solar energy production. A study conducted by the University of Oregon found that solar panels produced up to 10% more solar power when plants were grown underneath them.
The plants beneath the solar panels release moisture during a process known as evapotranspiration, which lowers the temperature of the air surrounding the plants. Solar panels are able to produce more electricity in cooler conditions.
Thus, agrivoltaics can increase your crop production and your solar production!
Diversify revenue stream for farmers
By installing solar, some farmers can make extra money without any extra work. Through programs like virtual net metering and solar renewable energy credits (SRECs), farmers can have another source of income besides their crops.
Small farms are under threat every day because of large factory farms, unpredictable international trade policy, and changing climate conditions. The excess money provided by installing solar can help many farms stay afloat when they otherwise could not.
One of the biggest advantages to agrivoltaic systems is their ability to make agricultural land more resilient to climate change, especially farms that are located in dryland ecosystems where increasing temperatures and water scarcity are already issues. Agrivoltaics is a way to keep food production high to feed our growing population, while climate change makes conditions less suitable for farming.
Solar PV panels prevent the plants from dying due to excessive heat, which only becomes more common with climate change. The combination of the shade of the solar panels and the cool microclimate plants create during evapotranspiration will keep the area around the plants at a lower temperature, allowing them to stay alive when they normally wouldn’t be able to.
Water scarcity is perhaps the most important issue we will face as climate change worsens. Temperatures will continue to rise, increasing the amount of water everyone, including farmers, needs. However, if a farmer installs an agrivoltaic PV array, they decrease the amount of water necessary to run their farm. This means they won’t be as affected by droughts as other farming operations, as they have already been conserving water with agrivoltaics.
Meet clean energy goals
The United States is set to make renewable energy development one of its top priorities under the Biden Administration. President Biden has continuously pledged to make our power sector carbon-free by 2035. To do this, a lot of solar energy needs to be installed.
According to researchers at Oregon State University, if just 1% of farmland in the U.S implemented agrivoltaics, we could reach our national renewable energy target.
Agrivoltaics can also help states reach their own individual climate goals, especially in smaller states like Massachusetts, where there is limited land for solar installations. The easiest solution is to allow farmland to double as both a food source and an energy source.
The impacts of agrivoltaics extend beyond farmer’s wallets
Agrivoltaics have the potential to lead to stronger, cleaner, more resilient local communities.
An increase in agrivoltaic installations will lead to the creation of local, good-paying jobs, as more solar developers and installers will be needed to complete the projects. It will also give a boost to the solar industry, which could eventually lead to solar price declines.
Agrivoltaic systems may also lead to the development and adoption of electric farming equipment. Right now, most farming equipment runs on conventional combustion engines. But as farms see the surplus of solar energy they produce, they might see the benefits of switching to electric vehicles.
Examples of agrivoltaics systems currently in use
Agrivoltaic systems have been installed all over the world in recent years, but most of them are used to study the relationship between crops and solar installations. Here are a few of the agrivoltaic energy systems already up and running:
Thin film, monocrystalline and polycrystalline panels are the main types of solar panels available for purchase. Piolenc’s experimental agrivoltaic system has protected grape vines and increased grape quality, all while producing clean energy. Image source: Sun’Agri
Agriovltaics developer Sun'Agri installed an 84 kW agrivoltaic system on a vineyard in Piolenc, France. The system is made up of 280 panels placed at a height of about 14 feet. What is truly unique about this system is that it uses artificial intelligence (AI) to move the solar trackers that the panels are installed on.
The artificial intelligence program used is programmed to maximize plant growth, not solar production. So, in the event of extreme weather conditions, like snow or heavy rain, the AI program can change the tilt of the panels to better protect the plants.
According to Sun'Agri, the agrivoltaic system allowed vines to be more resistant to heatwaves, preventing stunted growth. The panels also decreased water demand by about 30%. The quality of the grapes also saw improvement, with more red pigments and higher acidity levels.
The agrivoltaic system installed in Mallemort, France has helped apple trees use less water. Image source: Sun’Agri
Sun'Agri is also responsible for an agrivoltaic system on an apple orchard in Mallemort, France. Apple orchards account for about 3,942 farms in France, making them a significant part of the country's agricultural sector.
The orchard's solar system consists of 196 panels, installed at about 15 feet. So far, studies of the trees show that the water stress level of the shaded trees was 63% lower than unshaded trees in the orchard. Cooler temperatures were recorded in the area beneath the solar panels, which allows for increased solar production.
Iwaki City, Fukushima, Japan
By installing solar photovoltaic panels above figs, this Japanese farm has been able to make their land more productive - yielding not only fruit but also solar energy. Image source: Earth Journal
Agripark Iwaki, a farm in Japan, has an agrivoltaic system above their fig plants. Originally, the owners had debated totally converting the land to a solar farm, but government restrictions prohibited that. Instead, they installed 75 ground-mounted solar pillars, each with 25 panels.
The design of this system allows plenty of light between the solar pillars, so the figs can still grow. According to the owner of Agripark Iwaki, the solar panels have had no impact on fig fruit production. So, the farm gets to continue to produce the same amount of fruit, while also producing solar energy that they can use to power their operations.
Solar vs. farmland: why not have both?
Agrivoltaics are a dynamic solution to the issues we are facing in the wake of climate change. It addresses the need for reliable, clean energy to keep our society running without emitting tons of carbon dioxide. It conserves water in a time where water scarcity is a bigger issue than ever.
Solar sharing can increase crop yield and extend growing seasons which will help us feed our growing population, even as climate change makes farming less viable. Plus, agrivoltaic systems can help farmers save money and increase their financial stability.
It is important to keep in mind that not all farms will be suitable for agrivoltaic installations. It depends on the location, the crops, and the type of farming practices being utilized. However, it is a potential lifeline for family farms facing economic hardships.
Combining solar with farming is a win-win situation not just for farmers, but for everyone.
- Agrivoltaics is developing the same area of land for agriculture and solar power.
- Agrivoltaic systems can save farmers money by lower electricity and water costs, can potentially increase crop production, increase solar panel production, and can help us reach clean energy goals.
- You can find agrivoltaic systems throughout the world, but it is still a relatively new practice.
- Land use laws in different states can make it difficult for farmers to install agrivoltaic systems on their land.
- Agrivoltaic systems not only help farmers but can help build stronger communities by creating good-paying solar jobs that give the economy a boost.
Author: Catherine Lane | SolarReviews Blog Author
Catherine is a researcher and content specialist at SolarReviews. She has strong interests in issues related to climate and sustainability which led her to pursue a degree in environmental science at Ramapo College of New Jersey.