I've read about this before. His claims are a little out there, but not too far
If he can get the turbine engine to work properly it will charge those capacitors (not batteries) very quickly, so it won't need to run long. But since he is using capacitors instead of batteries, it will probably be coming on more often than he thinks.
On the up side of that coin, that turbine will be able to charge tham faster than they can be drained, even when at full "throttle".
The biggest piece of information I would be looking for is: How long can it run on those capacitors without a charge? I know it won't be long, but still... The answer to this question has a big effect on how often that turbine will be running.
These same types of turbines are currently used for power generation in some places, so the basic premise isn't new. But these are normally on for extended periods of time, not started and stopped on a constant basis. I'm not sure what kind of wear and tear that kind of use will cause (and the article I read, can't remember where, had the same question).
As of this article and the one I read there are still several questions unanswered. However, it's been a while for both (late '07 to early '08).