You forgot Beacon Power (BCON) flywheel based power management. No need to fire up those expensive, carbon rich fossil plants when a flywheel system can kick in in a second and even out grid demand.
Grid-based Energy Storage: Birth of a Giant [View article]
Having been at the BCON stockholders meeting last week and listened to management and toured the plant I have put my money there. I think they will be the winner in the minutes category.
Smart Grids' Year of Growth [View article]
Grid-based Energy Storage: Birth of a Giant [View article]