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Next up was Jon Wellinghoff of the Federal Energy Regulatory Commission, who coined the term “cash-back hybrid,” which clearly describes the benefit to consumers of plug-ins that not only charge themselves when demand is lightest and prices are lowest, but supply energy services to the grid as well. Collectively, Wellinghoff proposed, the batteries in millions of PHEVs could provide five distinct benefits: lowering green house-gas emissions, improving urban air quality, saving consumers money, bolstering power-grid reliability, and reducing oil imports.

How would those results be achieved? By making the energy stored in plug-in hybrids an integral part of the grid, using a few percent of each battery’s energy storage capacity to meet peak demand rather than adding new generating capacity—and by paying consumers accordingly.

The notion is called vehicle-to-grid power, or V2G, and its workings, economics, and practicalities were the meat and potatoes of the symposium. Wellinghoff’s model appeared to show the energy cost of a plug-in hybrid falling toward zero over time. Much discussion, and some derision, ensued.
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