It’s with great delight that I read about the handful of U.S. utilities that are seriously testing out various conservation, smart grid, storage and renewable technologies in an effort to extend greener offerings to customers. The latest is Duke Energy’s McAlpine Creek project, part of which involves the deployment of a 50 kilowatt solar PV array, consisting of 213 solar panels, at a substation that feeds the grid or, alternatively, can charge up a 500-kilowatt zinc-bromide battery system.

Duke hasn’t revealed any detail of the specific vendor technologies it is using, but I’m betting that the battery system for this particular pilot comes from Mass.-based Premium Power, which is largely operating in stealth mode at the moment. For one, the company’s TransFlow 2000 product fits the bill. It has 500 kilowatts of power and stores up to 500 kilowatts  2.8 megawatt-hours, is UL and CSA certified, and one of its main applications is for the time-shift of renewable generation energy. Boston Power, backed by VantagePoint Venture Partners, claims its storage product costs the same as pumped storage over the long term, or about 2 cents per kilowatt-hour. I also remind that last October, when Robert F. Kennedy Jr. spoke at an event in Toronto, he mentioned that Duke Energy had ordered $100 million worth of Premium Power’s batteries. An advisor and partner with VantagePoint, Kennedy also said a Canadian utility had ordered $100 million of the batteries as well.

Still haven’t nailed down who the Canadian utility is, but clearly Duke’s latest pilot project involves the TransFlow system. I spoke briefly with Bic Stevens, senior vice-president of business development at Premium Power and he remained cagey about the relationship with Duke. He would neither confirm nor deny that Duke was using the company’s product, though acknowledged it’s only a matter of time before details emerge. “As units get shipped out to big utilities they’re going to choose to advertise it or not advertise it, and eventually word will get out,” he said.

I would love to learn that it’s an Ontario utility (Ontario Power Generation, or Hydro One) testing out the Premium Power product, but I’m guessing — and this is purely a hunch — that Alberta’s EPCOR Utilities is the buyer. If there’s anyone reading this who has the scoop, please tell — I promise to keep a secret