I have to admit that the discussion that currently is building up on smart power grids and the role of electric cars leaves me clueless to some extend. We remember: The grid needs to be more smart than it is today because wind and solar energy tend t destabilize it. This tendency is a result of the fact that "alternative" energies, unlike conventional power plants, cannot be adjusted in terms of output power and timing a windmill produces electric power when there is wind, and this is not necessarily the moment when consumers are ready to buy this electric power. Nobody wants to cook his dinner at 2:00 am just because the wind is just high. Similar wisdom applies to solar energy.
So far so good. This is why the utilities need energy storage devices. But why do they reflect upon electric cars as the medium to save this energy? Well, yes, electric cars need to be charged anyway which tends to drive the demand for electric power. But the business models the car industry and the utilities are considering (and companies such as Better Place have puzzled out) aim for using the batteries in electrical and HEV cars as a kind of public energy storage. This means that car owners can re-sell their electric energy to the utility, and if they achieve a good timing, they even make money. This, in turn, anticipates that at any given moment there is a market price for electric energy and the grid as well as the car is smart enough to negotiate this price (computers and communications devices everywhere).
The business model also anticipates that typically drivers do not use up the electrical energy in their batteries. An empty battery cannot sell energy, it only can buy it. So which driver is willing and competent to refrain from utilizing the complete range of his car just to sell a bit of electrical energy valued at some cents? If one uses a car, he has a destination, no matter if he can sell some watt-hours or not. Thus, the energy available to resell will probably be in the magnitude of fragments of kilowatt-hours per car and day. In order to realize relevant energy storage capacities it will take a huge market with millions of participants. Plus, an expensive infrastructure to enable all of them to participate into the cent game.
Am I right? Anything wrong or ignored? And, given this effort, the core question comes to my mind which no automotive OEM or utility hitherto was able to answer: Why the heck don't those utilities buy their own battery farms and run them as stationary installation? It would be reliable, predictable, and it would not require such an immense effort. On the search for an answer I only come to one conclusion: The complex infrastructure and the equally complex business model of selling and buying stored energy outweighs batteries; the batteries will be even more expensive than this complex infrastructure. This would mean that car owners are funding the energy industry's infrastructure. I wonder how many will be willing to join the game.