Electricity is incidental (and a nice benefit) to the goal of "reduce evaporation of water from the irrigation canal and improve water quality".

> The duo went on to start Solar Aquagrid, an advocacy firm dedicated to reimagining aging canals, and partnered with the Turlock Irrigation District, UC Merced and the California Department of Water Resources to cover small sections of Turlock’s canals with solar panels. The new “solar canal” provides shade to limit evaporation and generates power all in one neat package. They call it Project Nexus, and it operates at the intersection of the state’s need for clean water and energy.

> ...

> But the canal site hosts more than just panels. Bales said they “have instruments out there to measure temperature, relative humidity, wind speed, incoming radiation, outgoing radiation, and a prototype instrument to measure evaporation directly.”

> When it comes to algae, the panels helped. “Last year when we drained the canal at the end of the irrigation season, there was a physical line on the sun side of the canal that had algae growth and then not algae growth from where the shade was,” Weimer said.

That it's green energy and can help supply the power demand is a bonus.