The troubles of lithium ion battery maker A123 Systems highlighted just how dangerous overestimating the size of a potential market can be. Analysis I’ve seen suggests that battery makers figured that by now the EV market and the thus the market for EV batteries would be 10X what it turned out to be.

So with that in mind we head into the emerging market of distributed battery storage and specifically the pairing of rooftop solar systems with battery storage. I’m a major fan of the idea because it truly gets customers off the grid, enabling them to store excess solar power for the evening time. I think this storage makes even more sense when paired with an EV because you could start to power cars from the stored energy.

SolarCity is working on a battery product. And now Seeo, backed by Vinod Khosla and google.org, is working with SunEdison on a battery-solar pairing product. Seeo’s innovation is a solid electrolyte that is lighter, is less prone to fires and shows improvement in energy density. Battery technology innovation is a snail’s pace game and getting funding right now to scale a battery plant is not easy. And given that there’s often a first mover disadvantage in new cleantech markets, it could be rough going out there for a new solar-battery combo. But as retail electricity prices continue to creep north and battery/solar prices creep south, the company that times the market right and has enough capital expand, will definitely take up some serious market share.