In recent years there have been significant innovations with respect to different types of energy storage of sufficient scale to serve as back-up for the grid (see e.g., Hall and Bain, 2008, IEA, 2005, IEA, 2008). Both improved storage and grid management have beneficial consequences for the delivery of electricity services more generally, irrespective of the supply mix. For instance, they can increase the reliability of supplies in the face of unexpected shocks (i.e. due to extreme weather events or earthquakes). They can also reduce transmission losses and increase efficiency more generally.