Video: Milking the sun, dairy takes on solar cogeneration

Video: Milking the sun, dairy takes on solar cogeneration

With a solar facility on its fleet maintenance center, diesel trucks that have been converted to cold plate technology and the use of a freon-based cooling system instead of ammonia, San Francisco Bay Area dairy Clover Stornetta Farms is no stranger to sustainable business practices.

The Petaluma, Calif.-based business works with a few dozen family-owned local dairies to process between 60,000-75,000 gallons of milk a day.

While the company had made several strides in recent years towards sustainability in its dairy processing plant, it was still looking for ways to lower its water and electricity use, as well as lower its carbon emissions, according to Joanie Benedetti Claussen, whose grandfather Gene Benedetti formed Clover Stornetta in 1977.

In June, Clover Stornetta became the first dairy in the U.S. to generate electricity and hot water through a hybrid solar technology known as cogeneration. The system was designed and manufactured by 3-year-old Silicon Valley startup Cogenra Solar based in Mountain View, Calif.

It’s the latest company across a number of businesses and organizations -- including Clover Stornetta's peers in the beverage industry – to install a Cogenra solar cogeneration system. In April, the Kendall Jackson Winery in Napa, Calif., installed its array. In March, the Maui Brewing Company in Hawaii announced announced plans to get a Cogenra system in place. And the Sonoma Wine Company debuted its array in 2010.

The Department of Defense, international hotels, Facebook (which uses it for its employee gym) and universities also use a Cogenra solar cogeneration system.

Photo of cow courtesy of Clover Stornetta Farms

“For the forseeable future, you’re going to waste a lot of solar energy,“ said Cogenra CEO Gilad Almogy in reference to today's traditional photovoltaic system. A traditional state-of-the-art PV system can only harness 15 percent of the sun’s rays into useful AC electricity, Almogy said.

Solar cogeneration increases efficiency by generating both heat and electricity using photovoltaic and thermal heating technology in tandem. So instead of losing the majority of the energy to the atmosphere, it is channeled into heating water instead, according to Almogy.

The technology is beneficial to industries which need a steady source of hot water, Almogy said – as well as those in search of a sustainable cooling source. This made it a perfect match for Clover Stornetta.

“As a dairy processor, we use a lot of electricity and a lot of hot water,” Benedetti Claussen said. “What the solar cogeneration system allows us to do is either use the energy from the sun or hot water for our wastewater treatment facility, or use electricity to run our plant.”

According to Matt McConnell, vice president of operations at Clover Stornetta, the company plans to use the additional energy generated for their wastewater treatment operations.

The company is on track to reduce water usage this year by 10 percent, which translates to 3-4 million gallons of water. And the solar cogeneration system will also prevent the release of 32 million metric tons of greenhouse gas emissions per year, McConnell added.  

While the $100,000 system will take five years to pay back, Almogy said that his company’s systems have been tested to last for 25 years. Clover Stornetta also took advantage of federal and state tax incentives as well (in the form of a corporate tax break and a state tax rebate) which reduced the cost by approximately 25 percent, McConnell said.

One challenge Clover Stornetta addressed before greenlighting the installation was how to make room for the solar array and hot water tanks despite limited space.

“They came to us and said ‘Here’s our solution,’ and we went back to them and said ‘Here’s what works for us,’ and they really adjusted the solution to fit our project,”  McConnell said. For example, Cogenra wanted the water tanks to be mounted on the ground, but Clover Stornetta ended up mounting them on its roof instead.

Clover Stornetta was able to jumpstart the process after meeting Gail Barnes of the Innovation Center for U.S. Dairy. Barnes, who works with dairies across the country on projects designed to meet the industry’s mandate to reduce greenhouse gas emissions by 25 percent by the year 2020, introduced the dairy to Cogenra.

“Clover is a three-generation, family-owned company which allows us to be nimble and advantage of a lot of things that larger companies can’t do,” Benedetti Claussen said.

Her company’s drive to innovate, Benedetti Claussen said, is not just based on the environment, but for customer expectations as well.

“We knew our consumers expected this of us,” she said. “So we have to continue to innovate, to be ahead of the game and to also keep our consumer base in our back corner.”