I recently came across an interesting report released in June by the Pembina Institute , an Alberta-based environmental think-tank, on large-scale electricity storage . The ability (or lack thereof) of the grid to take in all that new renewable power ranks as one of the main near-term risks to the growth of the alt energy sector, and cost-effective storage could go a long way in alleviating grid concerns. The report outlines the main technological options for storage along with their strengths and weaknesses. Although I wish there was more information on the costs of these technologies, as this is currently the main barrier to their deployment, I found the technological overview useful. Some of you may remember an article I wrote about Beacon Power over a year and a half ago. I have since exited my position in Beacon (on October 16, 2008, at $2.02) because (a) I wanted to put the money to work elsewhere and (b) I was happy with my gain. This is somewhat unfortunate as I had claimed in the original article that I intended on holding this stock for a long period of time. However, my belief in the eventual emergence of the storage sector remains as strong as ever. The main difference now with the time I wrote this article is that things are starting to move on the regulatory front with large-scale storage, and we could soon see incentive programs directed at this industry. This is, in my view, a sector to keep a close eye on. DISCLOSURE: The author does not have a position in the stock discussed in this article