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A large-scale solar array in California solves two major problems in two crucial sectors of the future.

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Christopher Neely's picture
Independent Local News Organization

Journalist for nearly a decade with keen interest in local energy policies for cities and national efforts to facilitate a renewable revolution. 

  • Member since 2017
  • 710 items added with 344,403 views
  • Feb 18, 2022

It’s no secret that California, and much of the American West, is facing significant water issues as precipitation becomes harder to come by and the weather gets hotter. It’s also no secret that PG&E, the electric utility serving much of the state, has faced its own problems as well, hiking up energy prices and proving unreliable.

Sometimes the answer to multiple problems is a single solution. On the Santa Lucia Preserve in Carmel Valley, CA, a new project is slated to solve persistent water and energy issues, while helping to make this land preserve a self-sustaining organism into the future.

The preserve, a 20,000-acre expanse of rolling chaparral hills, is preparing to debut a nearly 1,200 panel solar array, floating on a pond of treated wastewater the preserve uses to irrigate the property’s golf course. The solar array will help power the water pumping station that irrigates the golf course, and will provide crucial shade over the pond that will help save millions of gallons of water annually to evaporation.

The power output will be 487 kilowatts, able to subsidize 80% of the water pumping energy demand and the shelf life of the project is estimated to last 25-30 years. 

There has been a lot of discussion about the environmental impact of solar farms. The impact of sourcing the materials, the impact on the earth when installing these farms, typically on open land. Forrest Arthur, manager at the preserve, had to solve this problem if the preserve was ever going to get solar, since a key principle of the preserve is impact development that is “subservient” to the land.

Not only is this floating solar, but it is floating on treated wastewater, used to irrigate the preserve’s golf course (ironic that a land preserve would have a golf course, but it was there before the land became officially a preserve).The pond is man-made and lined, and attracts no wildlife activity that would be impacted by these floating arrays. 

Man-made reservoirs are everywhere. Treated wastewater reservoirs are becoming more common as water becomes a more precious resource and wastewater needs to be reused where possible. Evaporation will continue to be the unsexy issue of open air water reservoirs. It feels like floating solar arrays could be revelatory in the future

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Michael Keller's picture
Michael Keller on Feb 22, 2022

Not so sure covering a reservoir with solar panels is a great idea for the lake’s ecosystem. Would also appear to wipe out using the lake for recreational purposes. 

Christopher Neely's picture
Christopher Neely on Mar 4, 2022

I thought the same, but in this case, the pond is treated wastewater, safe to irrigate a golf course but not used for recreation or provides much habitat, except maybe to algae and microbiomes. 

Michael Keller's picture
Michael Keller on Mar 9, 2022

Factoid. In the East and Midwest treated sewage is routinely dumped into rivers that also serve as the intake for the water supply. Folks are routinely use the rivers for a variety of purposes.

Seems to me, the folks in the West need to take a broader view of the water supply, particularly as the West is facing droughts and population booms in areas that have always been deserts. More to the point, recycle wastewater for human consumption - it's called tertiary treatment. The amount of treated wastewater being dumped into the ocean by Californian cities is staggering. Therein lies the obvious solution to the West's water crisis which is sucking the environment bone dry. Ever heard of the Owens Valey?

VINCENT NARVAEZ on Jun 10, 2022

As a former employee of the Preserve WWTP I was part of the crew who assembled and launched the solar array project. The panels sit in one of four treatment ponds. The power generated offsets the costs incurred through PG&E which is significant. The array occupies around a 1/3 of the ponds surface area.

Tertiary treatment which is being used in wastewater treatment facilities throughout CA would be cost prohibitive here in this very small community. The daily flow levels are small and probably wouldn't justify it.

Additionally, The Preserve maintains the ponds for irrigation but also does maintain its small marine habitat called Moore's Lake. Fish, duck and other wildlife flock to it as it is a safe haven due to restrictions on recreational vehicles in the water (paddle power only).

The Preserve supports a wide array of wildlife and that is managed by the Preserve Conservancy.


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