Agrivoltaics: What Crops Grow Best Under Solar Panels?

Abstract

We need farms for food, and we need solar panels for renewable energy — what if we could combine the two? Find out if certain crops can grow well under the partial shade of solar panels in this agrivoltaics science project. (Note: you do not need access to real solar panels to do this project, any other source of shade will work!)

Summary

Areas of Science

Plant Biology

Difficulty

Method

Scientific Method

Time Required

Very Long (1+ months)

Prerequisites

None

Material Availability

Readily available

Cost

Average ($40 - $80)

Safety

No issues

Credits

Ben Finio, PhD, Science Buddies

Science Buddies is committed to creating content authored by scientists and educators. Learn more about our process and how we use AI.

https://www.youtube.com/watch?v=OpsG9G44nHY

Objective

Determine whether certain plant species grow better in full sun or partial shade. 

Introduction

Agrivoltaics combines the words agriculture and photovoltaics. Agriculture is the practice of growing crops and raising animals, usually for food or other uses. Photovoltaics is the process that solar panels use to convert sunlight into electricity. Agrivoltaics the practice of simultaneously using the same land for solar panels and agriculture (Figure 1). Some animals, like sheep, are well-suited for grazing around the panels to keep vegetation low, reducing the need for mowing. Certain crops can also do better and produce a higher yield in partial shade. All-day direct sunlight can dry some crops out too much. Shade from the panels can help keep the soil cooler and reduce evaporation. This type of dual-use of land can potentially be more efficient overall than using land for just one purpose.

Image Credit: Ben Finio / Science Buddies

Figure 1. Tomato plants in the shade under solar panels.

You can do a science project to test whether certain crops or plants grow better in full sun, partial shade, or full shade. The good news is that you do not need access to a large ground-mounted solar array like the one in Figure 1 to do the experiment. You simply need access to outdoor locations with different amounts of shade throughout the day to grow your plants. The procedure section will give you more details on how to do the experiment. Are you ready to help move our world toward a more sustainable future?

Terms and Concepts

• Agrivoltaics
• Agriculture
• Photovoltaics
• Yield
• Dual-use

Questions

• What are some potential advantages of agrivoltaics? What are some of the challenges?
• What types of garden plants or crops typically grow well in your area? How much sunlight do they require?

Materials and Equipment

• Species of garden fruits or vegetables that grow well in your climate, such as tomatoes, lettuce, strawberries, etc. Ask an adult for help or ask for advice at a local nursery if needed. Some libraries also offer free seed packets and even gardening classes. Try to test at least 3 different species for your experiment with different shade requirements. You will need at least 6 of each type of plant (3 for each shade condition). Depending on the amount of time you have available for your experiment, you can choose to germinate plants from seeds or purchase starter plants at a nursery or hardware store. 
• Gardening supplies such as a trowel, pots, and potting soil for your plants. We recommend doing the experiment with your plants in pots instead of planting them in the ground so you do not have to worry as much about weeding. 
• Depending on your climate, the weather, and the amount of water required by the plants, you may need a way to water the plants if you cannot rely entirely on rain, such as a watering can or hose.
• Deer/rabbit fencing or other pest repellent if needed in your area
• A location with as much sun exposure as possible (almost no shade, like what crops would experience if they were planted in the middle of a field). If you are in the northern hemisphere, this would typically be on the south side of a house or building, unless there are trees or other buildings in the way that create shade.
• A partially shaded location. You may need to consult with a local nursery or read the instructions on seed packets for how many hours of sunlight per day is considered "partial sun" for specific plants. This could typically be on the east or west side of a house or building, so it only receives morning or afternoon sunlight, but not both. You could also use a large object (piece of plywood, outdoor furniture, etc.) to create shade. 

This project follows the Scientific Method. Review the steps before you begin.

1. Before you start your experiment, decide how you will evaluate growth for each plant species, and when you will end the experiment. See the Science Buddies Measuring Plant Growth resource in the Bibliography for some ideas. Since you are growing crops, you can also measure yield, such as the number of tomatoes or the total weight of tomatoes produced by a tomato plant. 
2. Follow the instructions on your seed packets or plants to plant them in pots. Some plants may come in starter pots from the store (Figure 2), and others may need to be transplanted to larger pots. You should have six of each type of plant. Label your pots so you can keep track of your data later (e.g. Lettuce Full Sun #1, Lettuce Full Sun #2, and so on).

Image Credit: Ben Finio / Science Buddies

Figure 2. Basil plants in starter pots. A piece of plywood provides extra afternoon shade for three of the plants.

3. For each type of plant, place three of the pots in a location that will receive full sun. Place three pots in a location that will only receive partial sun (Figure 3).
   1. Check the seed packet/plant instructions for the definitions of full and partial sun (hours of sunlight per day).
   2. Make sure both locations will receive the same amount of rainfall. For example, do not place three of the pots directly under a tree or on a porch for shade if this means they will not receive as much rain.

Image Credit: Ben Finio / Science Buddies

Figure 3. Two sets of three tomato plants. The plants on the left in the image are on the south side of the solar panels and receive all-day sun. The plants on the right in the image are on the north side of the panels and only receive afternoon sunlight. (Note: these plants are planted in the ground instead of in pots)

4. If needed, take measures to protect your plants from pests (bug netting/spray, fencing, etc).
5. Create data tables for your observations, like Table 1.
   1. You can create a separate data table for each plant using the label system you created earlier for your pots.
   2. This table is just an example. The columns in your table may vary depending on your exact plan for measuring your plants. Add more rows or columns as needed.
   3. Make sure to add appropriate units to your column labels when needed, such as liters for amount of water or centimeters for plant height.

Swipe left to see more

Table 1. Example data table.

Day	Weather	Amount of water applied	Plant Height	Number of Tomatoes	Other Observations
1
2
3
...

6. Now, each day:
   1. Observe each plant and record your observations in the corresponding data table. 
   2. Care for the plants as needed, such as watering or weeding them. 
7. Keep making observations for as long as you have available to do your experiment. Depending on the time you have available, you may need to make your final observations and measurements before the crops are fully mature (for example, before tomatoes are fully ripe).
8. Depending on the types of measurements you make, you may need to remove the plants from the pots at the end of your experiment (for example, measuring dry plant mass by drying the plants in an oven, or measuring the plant roots, as described in the Measuring Plant Growth resource). Record these observations separately for each plant. 
9. Once you have collected all of your data, compare the full sun vs. partial shade conditions for each plant species. For example:
   1. Calculate the average total weight of the tomatoes per plant for the full-sun tomato plants.
   2. Calculate the average total weight of the tomatoes per plant for the partial-sun tomato plants.
   3. Make a bar graph with the average total weight of the tomatoes per plant on the y-axis and the shade condition on the x-axis.
   4. Repeat this process for other metrics that you measured (plant height, mass, etc.).
10. Compare the full sun vs partial sun conditions for each plant species. Did any plants perform better in partial sun than in full sun?
11. Based on the resutls of your experiment, which crops would you recommend be planted on an agrivoltaic farm? Which crops should be avoided?

Ask an Expert

Do you have specific questions about your science project? Our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.

Post a Question

Global Goals

The United Nations Sustainable Development Goals (UNSDGs) are a blueprint to achieve a better and more sustainable future for all.

This project explores topics key to Affordable and Clean Energy: Ensure access to affordable, reliable, sustainable and modern energy.

This project explores topics key to Sustainable Cities and Communities: Make cities inclusive, safe, resilient and sustainable.

Variations

Careers

If you like this project, you might enjoy exploring these related careers:

Plant Scientist

Log in to add favorite More Menu

• Read More

Career Profile

With a growing world population, making sure that there is enough food for everyone is critical. Plant scientists work to ensure that agricultural practices result in an abundance of nutritious food in a sustainable and environmentally friendly manner. Read more

Solar Energy Systems Engineer

Log in to add favorite More Menu

• Read More

Career Profile

Does the idea of harvesting the enormous power of the sun interest you? If you find this exciting, then you should think about installing solar photovoltaic panels on your house to collect free electricity from the sun. But how energy efficient is your home already? Can it get better? How many panels would your house need? What would the system look like? You can get the answers to these questions and more from your local solar energy systems engineer. These engineers help their residential and… Read more

News Feed on This Topic

 

, ,

Explore Our Science Videos

Build an Arduino Clinostat to Simulate Microgravity for Plants | Science Project

The Physics of Bouncing a Ball | Science Project

Protect Spacecraft from Space Debris: Make a Model Whipple Shield | Science Project