Want to cut your carbon footprint and get a buzz at the same time? Grab a bottle of wine from the Sonoma Wine Company in Graton, California. The winery is the pilot project for Cogenra Solar, a startup backed by top VC Vinod Khosla. It brings together photovoltaic and solar thermal technologies to produce hot water and electricity from a single unit.
Cogenra's technology reflects sunlight into a solar array that in turn faces down into a mirror. A tube located above the array carries liquid that has been heated by sunlight reflected off the mirror. That heat is then used to produce hot water.
The company explains:
Traditional photovoltaic (PV) systems convert approximately 16% of the sun’s energy into usable electricity, discarding the remaining energy as waste, mostly in the form of heat. Solar cogeneration captures this waste heat and transforms it into real value—hot water. This cogenerative solution has the added benefit of cooling the PV components, which boosts the system’s electric generation.
Cogenra is taking aim at the commercial market. "If you look at heat consumption, a substantial part is on the industrial level and the institutional level—jail, retirement communities, hospitals. Everywhere where there is industry, industry uses heat," says Dr. Gilad Almogy, Cogenra's CEO.
That includes wineries. As part of the pilot project with Sonoma Wine, Cogenra has set up a 272 kW electric and thermal installation to support the facility’s operations. "We give them electricity to run the plant, and heat to run the winery," Almogy says. The installation, which is partially funded by a $1.5 million research grant from the California Solar Initiative Research, Development, Deployment and Demonstration program, will be completed by the end of the year.