Can Solar Panels Help Plants Grow?

This article will explore the potential benefits of combining solar panels and plant growth in an approach called “agrivoltaics.” Agrivoltaics refers to co-developing the same area of land for both solar photovoltaic power and agriculture. With climate change threatening both energy and food production, agrivoltaics aims to maximize land use by integrating solar panels and crops on the same plots of land.

Combining solar power generation and agriculture has several advantages. The shade provided by solar panels can reduce plants’ water needs and heat stress. In hot and arid climates, this shading can increase crop productivity. At the same time, the plants underneath the panels can reduce temperatures around the solar arrays, boosting solar efficiency. Agrivoltaics allows double usage of land, increasing sustainability. This innovative approach also opens up new avenues for renewable energy adoption, as solar developers can acquire agricultural land.

This article will analyze the science behind agrivoltaics and explore real-world case studies. It will also discuss potential drawbacks and examine cutting-edge integrated solar plant designs. By thoroughly covering the pros and cons, this piece aims to provide a balanced look at whether solar panels can benefit plants and food production.

How Solar Panels Work

Solar panels work by converting sunlight into electricity through the photovoltaic effect. When photons from sunlight hit the solar panel, they knock electrons loose from the atoms in the panel’s semiconductor material, typically silicon https://www.livescience.com/41995-how-do-solar-panels-work.html. The electrons flow into metal conductors on the panel as Direct Current (DC) electricity. An inverter then converts the DC to Alternating Current (AC), which can power home appliances and devices. The photovoltaic cells in a solar panel each produce a small amount of electric current and voltage. Connecting the cells in series boosts the voltage, while connecting them in parallel increases the current. Most solar panels have 60 to 72 cells wired together to produce useful levels of electricity.

Photosynthesis in Plants

Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create their food, in the form of glucose (sugar). This process takes place in plant cells that contain chlorophyll, which gives plants their green color. The general equation for photosynthesis is:

6CO2 + 6H2O + Sunlight → C6H12O6 + 6O2

During photosynthesis, plants absorb sunlight using their leaves. The energy from the sun is absorbed by chlorophyll in the plant’s leaves. The chlorophyll is contained inside chloroplasts, which are tiny structures inside plant cells. When the sunlight energy is absorbed, it is used to break down the water and carbon dioxide molecules. This process releases oxygen as a byproduct. The energy is then used to combine the carbon from carbon dioxide with hydrogen from water to form glucose. The glucose provides food energy for the plant.

Therefore, sunlight is absolutely essential for plants to be able to undergo photosynthesis and produce their own food. Without adequate sunlight exposure, plants cannot photosynthesize properly, which hinders their growth and development. The rate of photosynthesis typically increases proportionally with increased sunlight availability. This makes sunlight one of the most critical factors for healthy plant growth through the process of photosynthesis (Source).

Combining Solar Panels and Plants

Solar panels and plants can be beneficially combined in an integrated system referred to as an agrivoltaic system or agrivoltaics. Research and projects have demonstrated that these systems allow land to serve multiple purposes – power generation and agriculture (source: https://science.howstuffworks.com/environmental/green-science/agrivoltaics-solar-panels-agriculture.htm).

An ongoing research project by Arizona State University is studying how to best integrate solar arrays and agriculture. They have investigated crop selection, spacing, and orientation to promote plant growth under the panels while maximizing solar energy production (source: https://theworld.org/stories/2018-06-08/energy-and-food-together-under-solar-panels-crops-thrive). The University of Arizona’s Biosphere 2 facility also has a Solar Power & Agriculture park showcasing integrated agrivoltaic systems.

Findings so far show that the partial shade created by solar panels can benefit agricultural crops in hot, dry areas by creating a cooler, moister microclimate. Integrating solar and agriculture holds great potential for more sustainable and productive use of land.

Benefits for the Plants

One of the key benefits of combining solar panels and plants is that it allows for more optimal sunlight exposure and angles for the plants. Plants rely on photosynthesis to convert sunlight into energy and grow. However, in a typical outdoor field, the sunlight comes from directly above. This can actually be excessive light that leads to overheating of plant leaves or inefficient photosynthesis. By growing crops under solar panels, the panels provide some shading that diffuses and redirects the sunlight 1. This allows the plants to receive sunlight from multiple angles rather than just from above. The diffused light can penetrate deeper into the plant canopy as well. Studies have found that this optimized light environment improves plant growth and crop yields compared to traditional outdoor fields 2.

In addition, the shade provided by solar panels can help reduce water loss from soil evaporation and plant transpiration. This is especially beneficial in hot, arid climates and can reduce the water needs of the crops. The panel shading also cools the surrounding air temperature, creating a more moderated microclimate that reduces heat stress on plants. Overall, the studies show that combining solar panels and agriculture can provide physiological benefits to the plants and improve agricultural productivity.

Benefits for the Solar Panels

One of the key benefits of combining solar panels and plants in an integrated system is the cooling effect the plants provide for the solar panels. As noted in an article on Fast Company, the plants underneath the solar panels help keep the panels cooler through a process called evaporative cooling (Source). The plants release moisture into the air through transpiration, and this moisture helps reduce the temperature around the panels. Lower temperatures have been shown to improve solar panel efficiency and longevity. One study cited in Scientific American found that cooling solar panels by even a small amount, around 3°C, can increase their power output by over 1% (Source). The natural cooling effect provided by the plants underneath is a win-win – benefiting both the plants and the solar panel performance.

Challenges and Limitations

Combining solar panels and agriculture can pose some challenges and limitations that need to be considered. Some key challenges include:

Space constraints – Finding the right balance between space for solar panels and space for crops can be tricky. Solar panels take up real estate that could otherwise be used for planting. This is especially challenging for smaller farms (https://www.statkraft.com/newsroom/news-and-stories/2022/agrivoltaics-combining-solar-panels-and-agriculture/).

Matching plant types – Certain crops may thrive better than others under solar panels. Lower light plants like lettuce do well, but crops needing more sunlight like tomatoes may struggle (http://www.climatehubs.usda.gov/hubs/northwest/topic/agrivoltaics-pairing-solar-power-and-agriculture-northwest).

Impact on yields – Reduced sunlight can mean reduced crop yields in some cases. Finding the right balance is key (https://www.sciencedirect.com/science/article/pii/S2666386423003028?via%3Dihub).

Innovative Integrated Designs

There are some creative designs that integrate solar panels and plants in innovative ways. For example, the PV-Leaf is a bio-inspired solar leaf design developed by researchers at Imperial College London that imitates plant leaves. The PV-Leaf allows water to move and evaporate, increasing solar panel efficiency by keeping them cool (Imperial College London).

Another innovative design is the solar tree, which combines a tree-like structure with solar panels. The shade provided by the tree allows plants to grow underneath while the panels generate electricity from the sunlight above. Solar trees are being used in agricultural and garden settings as a way to produce energy and grow crops simultaneously ( Pinterest).

There are also vertical farms that integrate solar panels into greenhouse-like structures. The panels provide electricity while also allowing optimal light exposure for plants grown along vertical surfaces inside the building. This design maximizes space and energy efficiency in urban environments.

As solar and plant technologies continue to advance, there is great potential for new integrated designs that leverage their symbiotic relationship. The bio-inspired nature of many of these innovations takes cues from the natural world to create sustainable human-made systems.

Future Possibilities

As the technology and techniques behind integrating solar panels and agriculture improve, there is potential to expand these systems more widely (https://www.statkraft.com/newsroom/news-and-stories/2022/agrivoltaics-combining-solar-panels-and-agriculture/). Here are some ways this concept could be expanded more widely in the future:

Wider implementation on farms and rural land – As more research demonstrates the viability of agrivoltaic systems, both economically and environmentally, there will likely be wider adoption by farms and on rural/agricultural land.

Urban and community integration – Incorporating agrivoltaics into urban environments and community spaces could provide localized clean energy as well as community gardens and small-scale urban agriculture.

More crop variety testing – Further research can better optimize which specific crops and plants grow best under and around solar panels in various climates and conditions.

Innovative design improvements – Engineers and researchers continue to refine panel arrangements, heights, spacing, and angle adjustments to maximize synergies between the solar panels and crops.

Dual-use of land and resources – Thoughtful agrivoltaic integration allows the same land to produce both clean renewable energy as well as agricultural crops simultaneously.

With improved technology, creative implementation, and further research, the future possibilities are bright for scaling up agrivoltaics and maximizing their potential benefits.

Conclusion

In summary, there are many potential benefits to growing plants beneath solar panels. The plants provide cooling for the solar panels, allowing them to operate more efficiently, while benefitting from the partial shade and protection (Wired, 2022). Combining solar power and agriculture, known as agrivoltaics, also makes efficient use of land area. While there are challenges in terms of adequate spacing, plant selection, and irrigation, innovative integrated designs are emerging. Early research shows promise that certain crops may thrive under panels, offsetting any reductions in total farmland (The World, 2018). Agrivoltaics has the potential to sustainably co-locate renewable energy and food production as both are critical resources for society.