A few of the flow battery folks were there: VRB Power and ZBB (an Australian company, I was surprised to learn), as well as other perennial battery developers, Electro Energy some of the flywheel companies: Vicon, Pentadyne, Active Power, Boeing, Beacon. and EPRI and the State of California was well represented, as well as lot of academics, consultants, and a few global firms scouting progress or talking up a pilot they were involved in. There were also a number of papers on concepts like compressed air storage, which have been around for years with no takers.
I felt I was watching the CHP discussion of 5 years ago all over again, except it was on storage. A lot of teams chasing a market that is unlikely to materialize in the way or of the size they are expecting. The bright spots included a realization that integration was the key, but there was very little sense of near term products or projects being brought to market.
The most interesting discussion I thought was by a Japanese firm I had not heard of called Power Systems Co. (Very little of their English language website is finished.) I am not sure why they were giving a paper at this particular conference, but the engineer who presented said they had built a $25 mm plant to manufacture a next generation of supercapacitors, that they termed NanoCaps, product name ECaSS, and were selling an earlier generation now in Japan. Frankly, they were the only credible presentation I saw on a near term commercial business.