Bob and Nathan,
Many thanks for shedding helpful light on how we measure stored energy. Just about where ever I hang out online or at seminars or hearings, the discussions focus on both mega- or gigawatts and mega- and gigawatt hours.
I take issue with your remark Bob that there is "no promising technology on the horizon to justify" energy storage investments is missing the point. Let us know with another comment here which of the projects I spotlighted do not hold some promise.
With a growing focus on microgrids, enabling wholesale market rules such as those in PJM, commerical and government entities wanting better reliability AND the California mandate, THIS sector is ready to grow quickly, especially compared to what it's been through since 2010.