If you’re a dedicated envirobites reader, you may have noticed there’s a buzz around pollinators. Bees, butterflies, and other insects help plants reproduce by moving pollen between individual plants. While insects have many roles in the ecosystem, pollinating plants may be the most important service that directly impacts humans. Many of the crops we eat require pollination to provide food for us. Approximately $14.6 billion in crop production each year relies, at least partially, on pollination.
This image from the article shows examples of solar farms (A) near agriculture and (B) a pollinator habitat at a solar facility. (credit A: Invenergy, LLC; credit B: Rob Davis, Center for Pollinators in Energy/Fresh Energy)
Crop growth is one service we require; another is energy. We use energy constantly, to power our phones and computers, heat and cool our houses, and light up our morning and evening activities. Much of this energy comes from electricity, and one of the growing methods to generate electricity is using solar power. While many people are familiar with rooftop solar because you may have seen it on houses, some solar power is collected in larger centralized locations. In order to collect the energy needed to provide electricity, solar farms are built that use some of the land in the US. While all of our energy sources use land in one way or another, we can also try to get the best use out of the land that we possibly can.
One idea that people have is to cultivate pollinator habitats at solar farms. If the operators of solar farms don’t pave or mow the area or apply herbicides (weed-killer), more pollinators could visit the area. This alternative management of the solar farms could provide benefits such as habitat diversity and connectivity, that can help pollinators thrive.
Scientists from two national labs analyzed data on where all the solar farms and agricultural (crop) farms in the contiguous US are. (This includes 48 states and the District of Columbia (DC), but not Alaska, Hawaii, or island territories.) The scientists know that pollinators can fly about a mile and determined how many crop fields are within a mile of a solar farm from the existing data. They considered a scenario in which solar farms were good environments for pollinators to live. If pollinators live at or around these solar farms and can fly to a field where there are crops, there might be an increase in crop production of 1%. The 1% value was chosen for calculations, but the actual change might be different. Even a small change like this could actually lead to an increase in economic output for the farmers. For soybeans and almonds there would be millions of dollars more crop value due to the impact of the pollinators. Other crops would also benefit.
This figure from the article shows the amount of agricultural land that is highly dependent on pollinators and is also near existing or planned utility-scale solar energy facilities. Source: https://pubs.acs.org/doi/full/10.1021/acs.est.8b00020
The benefit, however, varies based on location. Some states have much more agriculture near solar farms than others, and some crops are more dependent on pollinators than others. This overlap is highest in California, North Carolina, and Massachusetts. Less than 1% of total US cropland could benefit from solar-pollinator habitats, but the benefit at the local scale can be very high, especially in areas where crops are very dependent on insect pollination. The dark green states are also ones taking advantage of solar energy more than others.
This is a great example of how we can get more benefit from a project by putting in a little extra thought or effort. If we are already building a solar farm, we can consider how our other choices on that land might be able to make a positive impact. It also shows how local decision making can be important, because the benefit of pollinators at solar farms varies. Some locations might find that a different way of utilizing the space has a bigger impact. This research provides a great example of how we should always think about how to get the most benefit from everything we do and that many decisions can have multifunctionality.
Find the full story here: https://pubs.acs.org/doi/full/10.1021/acs.est.8b00020
Cover image from Argonne National Laboratory https://www.anl.gov/articles/can-solar-energy-save-bees