[BabyPeanut]

If you know of an active experimental study kindly post about it in this thread.

[BabyPeanut]

This page lists three demonstrations just recently funded.

NAS Battery Demonstration, New York Power Authority, White Plains, NY

Grid Frequency Regulation by Recycling Electrical Energy in Flywheels, Beacon Power Corporation, Wilmington, MA
http://www.beaconpower.com/

Demonstration of Commercial Energy Storage Device in Edge-of-Grid Application, Gaia Power Technologies, New York, NY
http://www.gaiapowertechnologies.com/

http://www.sandia.gov/ess/About/selected-projects.html

[khebab]

I know there are a lot of research around ultracapacitors:

IEEE Spectrum

[BabyPeanut]

Active Power Ships First CleanSource XR Unit
Thursday December 16, 6:30 am ET

AUSTIN--(BUSINESS WIRE)--Dec. 16, 2004--Active Power, Inc. (NASDAQ: ACPW - News) today announced the shipment of its first CleanSource® XR evaluation unit to one of the largest producers of electricity in the United States.

CleanSource XR stores energy in the form of heat and compressed air. When power is needed, the compressed air is routed through a thermal storage unit to acquire heat energy. The heated air spins a simple turbine-alternator to produce 5 to 85 kW of electric power for up to several hours. Unlike commonly used lead-acid batteries and engine-generators, CleanSource XR is non-toxic and produces zero emissions.

more at http://biz.yahoo.com/bw/041216/165165_1.html