[D_Alex]

One thing to add: Electric cars. They come with energy storage in-built.

By rough calculation, if 10% of cars in my city (Perth, Australia) were electric, their batteries could supply the entire city's demand for duration of about 2 hours (or 10% of demand for 20 hours etc). This could work really well for demand balancing and peak shaving - overcapacity (which in Perth is massive, since the policy is to maintain supply even on extremely hot days, when demand shoots up and generation capacity goes down) and spinning reserve could be tremendously reduced.

I suspect some good software and a little hardware will be needed to account for the owners' needs optimally.

[bjelkeman-again]

There is going to be an interesting startup market around this is my prediction.