Apparently, this billboard in San Francisco isn't just hype: it is, infact, a power plant, using 20 solar panels to generate more electricityduring the day than it consumes lighting itself at night. On a sunnyday, the billboard generates 3.4 kilowatts of energy, which is justabout enough juice for a family of four during the day. If it's cloudy,the output drops to 2.5 kilowatts. PG&E does not, of course, sayhow much the solar panels cost to buy, install, and maintain. My guessis that it's in the "you'll recoup the cost in a decade or so" range.Still, since we've got ugly billboards set up all over the placeanyway, wouldn't it be great if they could be put to some practical usebesides annoying consumers out of purchasing whatever they happen to beadvertising?
Source: livescience.comAdded: 9 January 2008