Sun or Shade?

“Land use issues are often critical to further solar development. Renewable energy requires on average 10 times more land than fossil fuels do per unit of energy. Moreover, solar panels are site-constrained, needing to be sited where the sun shines, whereas fossil fuels can be transported and burned in areas less exposed to human interaction, or close to low-income communities and communities of color whose voices are often ignored in siting decisions.”

                ~ David M. Kuchta

There is often conflict around solar panels. I’ve looked at placing some on my residential property, but our house roof is partially shaded by big trees. One company recommended just trimming the trees significantly, or just eliminating them. Pretty gobsmacking to think that in order to have solar power I would have to cut down eighty-year-old trees!

There has also been local controversy related to solar installations on open space lands that triggered concerns about habitat and community access. That’s why most of our local solar panels are located on unshaded roofs or commercial and industrial buildings. There ought to be a larger scale way to use solar panels that doesn’t interfere with use of the property.

I’ve seen large solar panel farms in the desert outside Las Vegas and in southern California that undoubtedly produce a significant amount of electricity. However, that land is not used for anything else — except for nature. Solar panels may provide a shift in the localized habitat, but it likely would be of benefit to most desert inhabitants.

Well, writer David M. Kuchta has noted a simple idea: “Agrivoltaics is the use of solar panels in agriculture to produce both food and electricity … Agrivoltaics involves mounting ground-mounted solar panels at a greater height than in usual solar arrays, leaving the soil underneath for agricultural production.”

“Using rural land wisely through practices like agrivoltaics is key to solar development. It can reduce its impact on farming communities and rural wildlife while increasing solar energy’s acceptance with the wider public… The panels provide off-grid electricity to the farm and/or grid-tied electricity to the local community. The food produced under the panels can raise crops for the market or provide fodder and shade for grazing animals.”

“One of the most common integrations of agriculture with solar panels, and the one that offers the greatest potential for electricity generation, is allowing animals to graze on the land beneath solar panels. This can be done at scale without the need for large farm equipment.”

My college Planning classes recognized the conflicting needs for different land uses, and identified ways to resolve those issues. Combining water storage with parks, thoroughfares with tree cover and pedestrian walkways, green roofs on city buildings, and other creative ideas have been successful. Kuchta notes, “Using land for multiple purposes has multiple benefits. Adding those benefits up, one review of agrivoltaic practices found that land productivity increased.”

“In providing shade, solar panels reduce evaporation of moisture from the soil below … Livestock and crops under the panels also require less water … Reciprocally, the vegetation underneath the panels reduces heat stress and increases the panels’ energy efficiency.”

I find it interesting that global warming is driving us to find non-carbon emitting sources of energy at the same time we are planting trees to create shade to help mitigate warming. Hmm, we need more non-carbon power generation and more shade … Seems like a problem just begging for this solution!

Additional information:

David M. Kuchta, Agrivoltaics: Where Solar Energy Meets Agriculture, July 28, 2022, TreeHugger

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