The panels will generate up to a total of 5 megawatts, less than 1% of the peak demand by the 103,000 customers in TID. But if they prove worthwhile, the idea could spread elsewhere on the 250 miles of canal. Such a system has been used in the state of Gujarat, India, but nowhere else, partners in the TID project said.
“It’s different, it’s new and it’s innovative, and that’s something that I think TID should be proud of,” board President Michael Frantz said just before the vote. “Change is hard, but the climate keeps changing, so it’s inevitable.”
HUGE POTENTIAL FOR VALLEY
The research will build on a study last year from the Merced and Santa Cruz campuses of the University of California. The authors estimated that covering all of the Central Valley’s 4,000 miles of canals could get the state halfway to its 2030 goal for clean power. That study led Gov. Gavin Newsom to propose $20 million for a pilot project in his 2021-22 budget. TID was chosen by the California Department of Water Resources and worked in recent months to refine the plan.
The effort is called Project Nexus. The partners include UC Merced and Solar AquaGrid LLC, a Berkeley-based company that sponsored last year’s study. One of the TID test sites is on about 500 feet of the Main Canal near Hawkins Road, about five miles east of Hickman. The waterway is 110 feet wide. The other site is on about 8,000 feet (about 1.5 miles) of the Ceres Main Canal and Upper Lateral 3, about three miles west of Keyes. It is 20 to 25 feet wide. The panels will be suspended over the canals with a generally southern orientation to maximize sunlight. They are scheduled to be fully in place by June 2023, following detailed design and permitting, and will be evaluated through 2024. The team plans to test several brands of solar panels. The project also involves storage of daytime power for use at other times. This could be with batteries, compressed air or water, or other means.
UC EXPERTS LOOKED AT EIGHT AREAS
The 2021 study’s lead author was Brandi McKuin, a postdoctoral scholar at Santa Cruz. The co-authors from Merced were Roger Bales, Elliott Campbell, Tapan Pathak, Jenny Ta, Joshua Viers and Andrew Zumkehr. They did not use actual panels on canals but assessed eight Valley locations for sunlight intensity and other variables. That report projected a modest evaporation savings if all of the Valley’s canals had solar shading: 0.6% of the state’s total irrigation supply. But that could be worthwhile to TID if its water supply is reduced by drought or regulations. The upcoming study will examine whether the panels interfere with operation and maintenance of the canals. TID workers need access during irrigation season to open and close valves and do other work. They are drained from mid-fall to early spring for removal of trash and major repairs.
The shading also could reduce the buildup of algae in canals, trimming the maintenance cost.
OTHER WATER SUPPLIERS ARE WATCHING
The neighboring Modesto Irrigation District will be watching the TID demonstration, a spokesperson said last year. It, too, is a retail power provider with transmission lines along many canal segments. The State Water Project and the federal Central Valley Project also have shown interest. Both use huge amounts of electricity to pump water south from the Sacramento-San Joaquin Delta. Installing panels along its own canals allows TID to avoid the cost of buying land for such projects. It now gets 7% of its power from solar, mostly a privately owned plant in the desert portion of Kern County.
The larger of the TID test sites also is where the district will soon build a small reservoir to improve control of the canal system. The 38-acre impoundment will capture water that otherwise could run out the end of the system and into the San Joaquin River. The board also heard Tuesday from Robin Raj, founder and executive creative director of Solar AquaGrid, who joined the meeting on Zoom. He said the project is a chance “to reimagine our utilities’ corridors, have them do double duty, work harder.”