Snack maker Frito-Lay has unveiled what it claims is the largest solar thermal system in the US at its Modesto plant in Central Valley, California.

The five-acre solar concentrator field includes 54,000 square feet of concave mirrors designed to absorb sunlight.

The PepsiCo-owned unit said the solar energy captured by the 192 solar collectors generates steam that helps heat the cooking oil used in making its SunChips snack.

The switch to solar power will significantly reduce the plant’s use of natural gas, the company said.

Half of the system is in operation and the rest is expected to be online by July.

The project is a public-private partnership and the California Energy Commission provided US$700,000 towards construction of the solar field.

“The plant will harness the power of Central Valley sunshine to reduce its natural gas use, air pollution and greenhouse gas emissions — all while helping us meet our renewable energy goals,” California Governor Arnold Schwarzenegger said at the dedication ceremony.