The big guys are swarming greentech.  Oracle, IBM and Google are going after smart grid and water grid applications.  Samsung is investing $20 billion into greentech.  General Electric is pursuing photovoltaic solar.  Areva, the nuclear power company, just bought CSP firm Ausra.  There are plenty of other examples.  Today I spoke with Kawasaki Heavy Industries, a $15-billion builder of trains, motorcycles, ships, helicopters, and energy plants. In collaboration with another Japanese giant, Mitsubishi, they're looking at smart grid applications -- specifically, grid-scale energy storage.

Just as the smart grid encompasses a wide swath of industries and applications, utility-scale energy storage also comes in a lot of flavors.  From instantaneous frequency regulation to fast response load leveling to massive power capacity and slow charging for day/night arbitrage, different energy storage applications are going to call for different technologies.  These technologies will range from flywheels to lithium ion batteries to sodium sulfur batteries to compressed air energy storage (CAES) to pumped hydro to ammonia, phase change materials, hydrogen, and much more.  Here's an article that touches on the diverse range of energy storage technologies.

And here's a chart that covers energy storage applications:

Kawasaki is looking to deploy nickel metal hydride (NiMH) technology for grid-scale energy storage applications.  (Note to ECD's fans: Stan Ovshinsky was the inventor of NiMH battery technology.)  NiMH is good at fast-charge and fast-discharge applications versus, say, sodium sulfur NaS technology, which is good for projects that require massive capacity, but is limited by its six-hour charge cycles and high operating temperatures.

Kawasaki's NiMH products are not in the prototype stage -- this is a mature product proven both technically and operationally, according to sources at Kawasaki Heavy. 
Kawasaki's initial applications are in trains, where the energy used in braking is stored in the NiMH batteries.  The durability of NiMH -- their ability to be cycled millions of times, as opposed to thousands of times for lithium chemistries, makes this a suitable application for this technology.  Kawasaki is already deploying test programs with this technology in train systems in Japan and elsewhere.  There is the potential to save up to 20 percent in power usage and costs using this energy storage scheme.  The batteries are also used as emergency backup for trains, as well.

Kawasaki envisions this technology being applied to smooth out the variability of wind farms and solar farms as well as having possible applications in the new field of Community Energy Storage (CES).  NiMH has a better safety record than Li-ion, and the historic objections of a memory effect have been solved, according to Kawasaki.  Other objections concerning the heavier weight of NiMH, while relevant for cell phones and laptops, don't apply to stationary use.

Watch out for the big players coming into greentech.

Here's a list of recent VC-funded battery companies: