Walking the 20 square miles of exhibitors at Solar Power International in Dallas last week, I met 400 Asian module vendors I've never heard of before, a really large number of new and incumbent module racking companies, and a few new microinverter companies.

There was also the occasional utility-scale battery firm with aspirations of providing on-grid support for solar power. It's still early days in this pursuit.

International Battery of Allentown, PA builds large-format rechargeable lithium-ion cells, batteries, and systems. The firm closed a $35 million Round C led by Digital Power Capital, an affiliate of Wexford Capital, in 2010.

I spoke with David McShane at the show, the Executive VP of the 100-employee firm. Lithium-ion comes in lots of formulation flavors and International Battery employs lithium-ion phosphate, "the safest lithium-ion chemistry," according to McShane.

Last year I spoke with International Battery's then-President and CEO Dr. Ake Almgren. In his words, "What makes us different is that we develop and manufacture large-format prismatic lithium-ion cells using a water-based manufacturing process. We work with lithium-iron phosphate and lithium cobalt manganese, but we are chemistry agnostic -- we are not an inventor of lithium chemistries."

The water-based process does away with the need for an organic solvent -- a "big deal," according to Almgren. The solvent, NMP (N-methyl-2-pyrrolidone), is less than green and must be introduced and extracted from the process. Eliminating NMP results in "much lower processing costs," according to McShane.

Almgren said, "There are compelling benefits from the company’s unique, truly large-cell technology.” The IB batteries are not your standard flashlight-sized battery -- they are construction-brick-sized, and that confers some advantages in battery management and control, according to the CEO. In Almgren's opinion, "Tesla [Motors] didn't have access to prismatic [technology], but if they were to design their battery system today, they would use prismatic cells." (In fact, Tesla is looking at prismatics for their current designs from Panasonic and others.)

McShane said, "It's difficult to move the 18650 cell any further down the cost curve."

Almgren also said, "Our large prismatic cells are, depending on size, the equivalent of 20 to 80 of the small wound cells. We don't need to connect and wire these together and we don't lose energy density from needless wires and connectors," also adding: "Fewer connectors equals fewer thermal issues and reduces the need for forced cooling." He went on to say, "We can control and monitor the voltage, current and temperature of each cell to constantly balance the system."

IB goes after stationary applications, not portable tools or consumer transportation.

There is a range where Li-ion fits, according to Almgren -- up to about five megawatt-hours. Above that, NaS works best, especially if six-hour charge and discharge rates are acceptable.

The firm is still in the sampling and trial stage with a factory capacity of 30 megawatt-hours, which is scalable to 200 megawatt-hours.

IB was selected by utility AEP for its Ohio gridSMART project which is siting batteries in customer backyards for Community Energy Storage applications. There are some videos here showing the rather involved process of installing these below-ground, approximately 50-kilowatt-hour storage units.

IB is working with the military on forward operating tactical programs that combine gen-sets with batteries.

Finally, IB is working on a bulk storage project with a grant from the Pennsylvania Energy Development Authority.

When it comes to lithium-based battery chemistries, there is always talk of a lithium shortage or the U.S. being beholden to China or Bolivia for lithium the same way we are beholden to OPEC for oil. In Almgren's view, "Even in the most aggressive growth scenario, lithium supplies will not be a problem. It's the more exotic materials like cobalt, nickel and manganese that might be a problem." Simbol Mining is a startup focused on developing lower-cost lithium and extracting other elements from geothermal brines.

According to Dan Rastler of EPRI in an earlier interview, "We need to get below $300 per kilowatt-hour installed, all in." He said that the current cost of Li-ion ranges from $400 per kilowatt-hour to $1,200 per kilowatt-hour.

To break into the battery business, startups have focused on designing, manufacturing and selling their own lithium-ion or rechargeable zinc batteries. Unfortunately, it's a high-risk, capital-intensive endeavor that requires scientific creativity and engineering breakthroughs.

The companies that succeed at this challenge face an even more daunting task: competing against giants like LG and Toshiba that have extensive R&D teams, worldwide sales channels, and enormous factory capacity. Plus, they've got the financial resources to allow them to lose billions during temporary downturns in an already low-margin business.



Other venture-funded battery firms include Lion Cells, Enovix fka MicroAzure (Li-ion), Atraverda (bipolar lead acid), Revolt, PowerGenix, Anzode (zinc chemistries), and other battery technologies: Nanoexa, Infinite Power Solutions, Thin Battery, Carbon Micro Battery, Enfucell. Here's an article on available energy storage technologies.