21st century commandeering?

In the June 6th issue of The Economist's Technology Quarterly, there is a really interesting article on smart grids. "In order to accommodate the flow of energy between new sources of supply and new forms of demand, the world's electrical grids are going to have to get a lot smarter" (page 15). This idea has been getting a lot of media attention lately because of the amounts of money being allocated to infrastructure by the Federal government. What it essentially means is that the grid would have to be become more interactive, with information flowing from consumers to the generators instead of just having energy flow the old-fashioned way. One example that the article highlights is the possibility that a smart grid, in combination with new technology in electric car batteries, could allow the distributed storage of excess generating capacity from electricity generating plants. Basically, individual car owners would allow their cars to be used to store electricity off of the grid at off-peak hours, and then ostensibly to allow the grid to take that electricity back at a higher peak time. What is fascinating is that this would mean that private property is being at least partially commandeered for public purpose - not in the traditional sense, and not without permission and/or compensation, but it brings up all kinds of logistical questions, blurring the line between public and private property. It is ironic that the automobile, ultimate symbol of American individuality, could quite possibly become the first widespread and most acceptable instrument of collective action in our country.