PUT SUNLIGHT IN YOUR POCKET

How about a city full of electric cars, plugged into a smart grid, downloading and storing energy from solar installations in their batteries while they sit in parking garages waiting for the evening commute, and then sending their excess electricity back to the grid during dinner time? See The Austin, Texas, "Plug-In Partners" program.

Storage Is Key
Leah Krauss, April 12, 2007 (UPI)

WHO
Assistant professor of industrial engineering and operations research/University of Massachusetts, Amherst, Erin Baker, describing the technological progress of the photovoltaic solar systems business

WHAT
The installation of home- and business-sized photovoltaic solar systems cannot become a major factor on the national electricity grid until the intermittency of solar energy availability is coupled with a storage method. Specific battery technologies were not described.
Concentrating Solar systems were not included in the study and Baker said they are more readily adapted to grid needs.

WHEN
The report assessed solar energy’s role in electricity generation in 15-year chunks through 2095.

WHERE
Baker’s assessment will be published in Energy Economics journal later this year.

WHY
Intermittency prevents solar from feeding more than 20% of the grid’s power. The development economic storage technology is “critical.” Right now, the only thing that makes the investment in small-scale solar systems feasible is the utility reductions from feeding electricity to the grid. If it could instead be stored for later use, the pay-off for the investment would enhanced.

QUOTES
- Baker: "Electricity supply has to be equal to the demand all day; otherwise there are blackouts. Solar is intermittent -- even a cloud blowing by can push solar sources off the grid quickly…In order to push solar beyond the 20 percent limit, the electricity (produced at peak sunlight hours) has to feed into batteries that can later feed into the grid.."
- University statement on the Baker reports: "Even if there are research breakthroughs that made the costs of photovoltaics comparable to or less than that of fossil fuels -- roughly 3 cents per kilowatt hour by 2050 -- there would still be a limited impact on emissions unless the advances are combined with improvements in low-cost storage…"
- Baker: "There is definitely potential out there…It's well worth making the R&D investment ... (in a) whole portfolio that includes solar, batteries, and even other technologies like wind."