A floating 1,178-panel solar project at the Santa Lucia Preserve sets a new industry standard.

As chief operations officer at the Santa Lucia Preserve, Forrest Arthur says the work of protecting and reinforcing the sustainability of the rolling 20,000-acre expanse in Carmel Valley is a well of inspiration. However, there was one day a few years back that he calls one of his most inspiring, one he will never forget.

A central mission at the Preserve is to work toward a level of self-sustainability that can last hundreds of years. This drives the Preserve’s principle of low-impact human development that Arthur says needs to be “subservient to the land.” Arthur admits the path to self-sustainability in a modern and changing world is littered with obstacles. Electricity comes mostly from PG&E and mounting solar farms on the ground would violate the Preserve’s low-impact principle. Water for drinking and irrigation comes from a series of wells hooked up to underground aquifers, as well as five irrigation ponds that collect 50 million gallons per year; however, California is becoming drier and hotter, which means less runoff to collect and accelerated evaporation to the tune of 13 million gallons per year. Drilling more wells would similarly run in contrast to the low-impact principle.

What to do? It was a problem that needed solving. Arthur came across the answer, on a website for a winery in Northern California: floating solar panels. Developed by French company Ciel & Terre International, not only did the panels offset the winery’s water pumping costs, they also covered a majority of the pond, providing the shade needed to slow evaporation.

A small-scale beta version of the strategy was successful on the preserve in 2018, the only obstacle being the county’s permitting process since this was the first of its kind in Monterey County. Now, the preserve is preparing to unveil the completion of its latest project, a $1.5 million, 1,178-panel solar array, floating over an irrigation pond. The panels, installed by Pacific Grove-based Applied Solar Energy, are eight times the size of the beta version, cover 60 percent of the pond, will help save up to 5 million gallons of water from evaporation and will take 80 percent of the electricity demand required by the Preserve’s private golf course off of the PG&E grid.

“Evaporation control is the real sexy component of floating solar. You’re not only getting power reduction, you’re also shading the water,” Arthur says. “Water is a finite resource. We’ve got to find a way to do something different than what we’ve been doing for the last 100 years.”

Jimmy Ferreira, a project manager with Applied Solar, says one of the largest obstacles will be cleaning the panels. The beta version, a fraction of the size of the latest project, required two employees working two full days once a month. Arthur says they are working to invest in an automatic cleaner to save on labor costs.

Arthur says they are only waiting for an administrative approval from PG&E to put the solar array into operation; he expects to start it up in March.