Unfortunately, no one outside of EEStor or ZENN (and maybe Lockheed) has ever seen the system in action. Even after the Q&A its not clear if even ZENN has seen the ultracapacitor working. Several people asked about the ultra-cap and Clifford repeatedly responded that the non-disclosure agreement prevents him from commenting. Even though ZENN previously claimed the EEStor system would be ready by the end of this year, Clifford only said that an EEStor powered cityZENN would be in production by late 2009.
Clifford did hedge by saying the cityZENN is not dependent on EEStor, implying that it could be built with a conventional battery instead. We'll just have to keep watching. Thanks to yanquetino for the tip!
[Source: The Globe and Mail]