Solar power is being deployed everywhere at every scale.
One of the interesting challenges is to integrate solar panels with existing infrastructure. Not just roof top solar, but solar in farm fields, on railways, and floating on reservoirs. Wherever the sun shines.
The idea, of course, is to generate power in ways that enhances other important activities.
One concept that seems obvious is solar arrays atop desert canals. The sun shining on canals does no good, and promotes evaporation—the last thing we want. So, if we can put a solar roof overhead to gather power and shade the water it would be a big win, no?
This winter Roger Bales writes about a demonstration project underway in California [1].
California has a lot of canals, and estimates indicate that if they were covered with PV arrays they would generate a significant fraction of California’s current electric production [2]. Models suggest that the water will cool the panels, too, increasing electric production by a few percent.
Just as important, covering the canals would reduce evaporation by half or more, and save millions of liters of water. Shading will also reduce aquatic growth in the water, reducing the use of herbicides in the water.
The economics are decent, too. Land for solar arrays is not cheap; so obviously there are advantages to using otherwise unused space over the canals. Building the arrays is a bit tricky and expensive, since they will be giant roofs with irregular footprints. But overall, the benefits outweigh the costs, making this concept economically feasible.
I would say that one of the big open questions is how to distribute the generated power. Canals are long, thin footprints, mostly through sparsely populate areas. Local farms and settlements could certainly benefit from power off nearby canals, but presumably there will be a desire to deliver power to the grid. How will that work? And how much will that cost?
Still, I have always been offended by open canals in the desert. I’ll be much happier to have them covered over, generating power. And I’m much happier covering over existing canals than covering over more land.
- Roger Bales, First solar canal project is a win for water, energy, air and climate in California, in The Conversation, February 22, 2022. https://theconversation.com/first-solar-canal-project-is-a-win-for-water-energy-air-and-climate-in-california-177433
- Brandi McKuin, Andrew Zumkehr, Jenny Ta, Roger Bales, Joshua H. Viers, Tapan Pathak, and J. Elliott Campbell, Energy and water co-benefits from covering canals with solar panels. Nature Sustainability, 4 (7):609-617, 2021/07/01 2021. https://doi.org/10.1038/s41893-021-00693-8
Robert McGrath's Blog 