National Pumped Storage Projections: 2008-2035
The US Department of Energy's produces an Annual Energy Outlook on Generating Capacity that lays out projections for both renewable and conventional electric power generation through 2035. This report show no increases in pumped storage capacity are required to meet the the United States' energy strategy.
As highlighted, this summary report reflects that the US currently has sufficient pumped storage capacity combined with a diverse range of generating capabilities. The DOE and power industries are pursuing new generation capacity and an advanced Smart Grid strategy to reduce emissions, improve efficiency, enhance reliability, and provide greater energy security and flexibility while accommodating new energy technologies, including renewable, intermittent and distributed sources.
More details on these generating projections can be found here:
The full 2011 Outook report can be found here: