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

ExRo says its technology can dramatically improve the efficiency of turbines because its unique design allows the generator to adapt more quickly to changing wind conditions and tap a wider range of wind speeds. In addition to my column, you can find more detailed explanation of ExRo’s technology at Greentech Media and Technology Review.

And let’s not forget the potential of hydraulic wind-energy storage, or EEStor’s EESU and its massive potential for storing wind energy. “We’re talking to people very seriously about that,” says EEStor co-founder and CEO Dick Weir.

Oh, and I should also give a brief update on what Thane Heins is doing and its potential benefit to wind-turbine generators. You’ll recall that Heins’ company, Potential Difference Inc., says it has come up with a way to eliminate Back EMF in a generator that acts as a source of magnetic friction and reduces the generator’s efficiency. Eliminate the Back EMF and you get more output from the generator — theoretically. Heins’ has signed (or is close to signing) a licensing agreement with Montreal-based Tesnic Inc., a startup developer of small vertical-axis wind turbines. If Heins’ approach does eliminate the Back EMF, it will allow the turbine to operate at much lower wind speeds because the magnetic resistance will be eliminated. “I don’t have any comment at this point in time… it’s too premature at this time,” said Tesnic founder Horia Nica when contacted by phone.

I’m mentioning all this stuff because I think it’s important to remember that the renewable technologies we see being deployed today aren’t necessarily representative of what we’ll see, say, in 10 years. People seem to appreciate this point more with solar technologies, but not with wind — that is, it’s just a big windmill, right? For all the limitations of wind energy, mostly related to its intermittency, the technology behind it can and will significantly improve. As it does, it will hopefully silence more of the anti-wind folks and inspire electricity system planners who, to date, have approached wind with a skeptical eye.

Then Kennedy throws out this zinger: The company has a $100 million order for its batteries from a Canadian utility, and another $100 million order from Duke Energy.

Wahhhh? I figured he mispoke, that he was exaggerating, and as an advisor confused some facts. After the speech, I sat down with him and asked him about that comment. He seemed a bit taken aback by my interest, but didn’t backtrack. I asked about the Canadian utility, and he confirmed but said he couldn’t name the utility. I asked about Duke, and he confirmed. He stuck to the $100-million figure for each order.

Now, there’s not much known about Premium Power, beyond VantagePoint’s investment. In 2006 the company was awarded a $500,000 grant through a trust overseen by the Massachusetts Technology Collaborative. The company said at the time it planned to use the money to “scale their stacks into a large-scale Zinc-Flow 9000 system suitable for integration with renewable-energy sources such as wind and PV for load-leveling.”

Now that’s intriguing. Premium Power’s Web site doesn’t mention the Zinc-Flow 9000, and strangely it has removed all past and present press releases from the site. Yet here we have Kennedy, an advisor to Premium Power’s top investor and certainly a man armed with a wealth of knowledge, talking about $200 million worth of energy-storage orders.

Hmmmm… this could  be interesting.

One More Note: Kennedy also said Premium Power’s battery costs “less than” $200 per kilowatt-hour. That compares favorably to sodium-sulfur batteries from companies like Japan’s NGK, which cost about $250 per kilowatt-hour, and vanadium flow batteries from companies like Vancouver-based VRB Power, which cost about $400 per kilowatt-hour. If Premium’s zinc-bromide battery is truly half the price of the VRB battery, then the economics of such storage become much more compelling.