The CEOs of Alta Devices and Amprius spoke at an energy event at Orrick today.

Todd Kimmel of Mayfield Fund called these firms "really disruptive materials science" at the event in Menlo Park, California.

Alta Devices is a quasi-stealth thin filmsolarfirm. Amprius is a nanostructure battery company.

Chris Norris, the CEO of Alta Devices, a gallium arsenide (GaAs) thin film solar firm that we've covered in detail here, spoke at the event but added very little new to what he's already said. Their goal is to "compete with fossil fuels without government subsidies" and get to a levelized cost of energy of $0.06 to $0.07 per kilowatt-hour. Norris said that the firm has received $120 million and he thinks they're "halfway there" in terms of the amount of funding raised.

Given that the firm is still very far from actual production, I'd venture to say that Norris might be mistaken. If the firm is going to be a manufacturer of PV modules or cells at scale, they will have to raise a lot more than $120 million. The coming years will reveal the amount they'll need.

Norris said that the single crystalline, direct bandgap structure of GaAs, "a perfect crystal," distinguishes its technology from the CIGS players.

Last month the firm announced that it received $72 million from August Capital, Kleiner Perkins Caufield and Byers, Crosslink Capital, DAG Ventures, New Enterprise Associates (NEA), Presidio Ventures (a Sumitomo company), Technology Partners, Dow Chemical and new investor Alberta Investment Management Corporation (AIMCo), Good Energies, Energy Technology Ventures (a joint venture involving GE, ConocoPhilips and NRG Energy), and Constellation Energy. (These days, raising large funding rounds for solar firms obviously requires long lists of investors.)

Kang Sun, the CEO of stealthy battery startup Amprius, raised $25 million in a round led by Kleiner Perkins, with VantagePoint, IPV, Trident, Google's Eric Schmidt, and Stanford University. The firm is using a silicon nanostructure to replace a carbon anode system in batteries. Sun claims that silicon has "an intrinsic energy density ten times higher than carbon." He called Amprius "late science stage, early engineering stage" and noted that the firm's technology is four times better than current technology.

The company started in 2008 with a mission to make anodes and advanced materials that, presumably, it would sell to established manufacturers. According to Michael Kanellos' reporting, Amprius is studying its options: it may produce anodes or it could go into the battery business. A final determination has yet to be made. But clearly, the component option is on the table.

Sun was the founder of solar panel tracker company RayTracker that recently sold to First Solar. He revealed, in what I believe is the first public disclosure, the sale price of the firm. He said that after receiving $3.5 million in venture funding from Idealab, Quercus Trust, and Phoenix Fire, the investors received a multiple of 12.8 or a sale price of $44.8 million.