by Graeme » Tue 16 Sep 2014, 19:25:45
Stem Banks $100M to Finance No-Money-Down Energy Storage
$this->bbcode_second_pass_quote('', 'S')tem, a behind-the-meter energy storage startup, just closed on a $100 million fund to finance distributed energy storage at commercial and industrial customers. The fund is provided by B Asset Manager, a New York City-based investment adviser in the insurance industry, according to a release. Stem has also received venture funding from Angeleno Group, Iberdrola and GE Ventures.
As the energy storage industry matures, the need to scale up requires increased amounts of capital. The market environment has parallels to the residential solar industry of eight years ago, when companies such as SolarCity and Sunrun were starting to raise capital for leased solar systems. That leasing model initiated a furious amount of growth that continues to this day in the residential solar space.
Is leasing the direction for behind-the-meter energy storage?
"This is a very big vehicle, and it will enable us to have as much as we would need over the next...twenty-four months. As we expand into more markets, we're going to need more of that financing. We're in Hawaii, New York, and we're winning in California," John Carrington, CEO of Stem, told GTM on Monday.
greentechmediaUnderwater Compressed Air Energy Storage: Fantasy or Reality?$this->bbcode_second_pass_quote('', 'U')nderwater Compressed Air Energy Storage (UW-CAES) — a step beyond underground energy storage in caverns — may soon offer conventional utilities a means of long-duration load shifting for their large-scale electrical grids, and niche microgrid operators a means of reducing their fossil-fuel dependence, say its advocates.
More than 40 percent of the world's population lives within 150 kilometers of a coastline. Thus, the hope is that UW-CAES can benefit both from existing and future wind and solar microgrids as well as from coastal cities using conventional electrical grids.
The basic concept involves some form of “energy bag,” a balloon-like vessel made of stretched fabric, which is anchored to a sea- or lakebed. When energy is needed its compressed air can be released to drive turbines.
“For UW-CAES [at depths of 400 to 700 meters], the pressure remains almost constant for all levels of fill,” said Seamus Garvey, a professor of dynamics at the University of Nottingham in the U.K. “In effect, this means that for a given upper pressure, each cubic meter of air storage delivers about three times as much energy storage.”
Maxim de Jong, CEO of Thin Red Line Aerospace near Vancouver, Canada, says with such compressed air storage, it’s best to use high-efficiency Rolls Royce-like turbines.
“If you pump air into a cavern, you have a fixed volume. So the more air you let out of a limestone cave with compressed air, the more the pressure is going to drop,” said De Jong. “But with UW-CAES, the ocean [pressure] is always pushing on the bag.”