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MANAGEMENT By Ted Rieger, senior feature editor olar cogeneration energy sys- tems that simultaneously heat water and generate electricity are now in use at winery facili- ties operated by Kendall-Jackson and Sonoma Wine Company. Man- ufactured by Cogenra Solar, based in Mountain View, Calif., these sys- tems are providing 50% or more of each facility's thermal energy needs for hot-water heating, sav- ing on the cost of utility-provided natural gas. Traditional solar panels can lose up to 80% of the sun's energy in the form of wasted heat. By effi- ciently collecting this heat, Cogenra systems provide both hot water and electricity. According to Cogen- ra, the resulting benefits deliver five times the energy output, three times the greenhouse gas reduc- tion, and twice the financial returns of other forms of solar energy. Cogenra system arrays can be roof- or ground-mounted. Each module is designed with a curved 52 VINEYARD & WINERY MANAGEMENT NOV - DEC 2012 solar reflecting mirror that con- centrates light and heat on a con- ventional solar photovoltaic (PV) panel positioned above the reflec- tor. A glycol/water mixture is piped behind the PV panel that absorbs heat as part of the water thermal heating system. The glycol serves as overnight freeze protection dur- ing cooler months. This liquid heat transfer medium is in a closed-loop system that is circulated through a heat exchanger AT A GLANCE Solar cogeneration systems for wineries efficiently heat water for cleaning operations and generate electricity. Cogenra Solar manufactures and sells the systems, or will install and operate systems under a Heat and Power Purchase Agreement. The systems can provide five times the energy output, three times the greenhouse gas reduction, and twice the financial returns of other solar energy systems. Kendall-Jackson and Sonoma Wine Company use solar cogeneration systems. WWW.VWM-ONLINE.COM coil within a ground-level tank to preheat water. This heat exchanger also cools the glycol mixture that is returned to the solar PV system for reheating. The glycol mixture passing behind the PV panel simul- taneously cools the panel to help increase its efficiency for electric power production. An issue with PV solar electric systems is the loss of generation efficiency resulting from the panel retaining heat. Standard PV electric systems operate at effi-