As always, readers are encouraged to submit comments or even email feedback (I can't promise to be super-responsive, however, since this isn't my day job)... Received the following thoughts from a fellow cleantech investor in response to last week's post on engine re-designs and auto drivetrains:

I just wanted to say I agreed completely with what you said about auto technology deals. I have seen a bunch of them and turned them all down for the reasons you mentioned - it is just intrinisically not a good space for VC investors. If anything I think you were overly diplomatic! Takes forever to get to market, very capital intensive, low margin business, and then even if you get to market, selling into auto industry OEMs simply sucks, no two ways around it. And particularly anything related to power plant/drive train. The two other negatives you didn't mention are constant pricing pressure and onerous vendor requirements - selling to the Big 3 (and their ilk) is brutal - constantly playing you off your competitors, demanding your cost data and then pricing you down to the bone, terrible payment terms, etc etc... Personally I won't touch anything designed to sell to Big Auto OEMs with a 10 foot pole.

The only comment I would make is that things can look a little different for a) aftermarket; and b) trucks and buses. Trucks and buses tend to have shorter commercialization cycles, more retrofit activity than passenger vehicles, and recently more stringent regulatory requirements, so there might be some opportunities there. For instance we have seen a number of emission control technologies aimed at complying with the next gen European diesel regs, which are strict and coming fast. Still lots of intrinsic problems in these deals, but there is a sense of urgency from the OEMs, which helps a little bit. Though not enough in my opinion!

Good follow-on comments worth sharing, thanks much... It would be good to share a response from someone in the investment community with a different perspective as well, please feel free to drop me a line...

Also, missed mentioning ReVolt's EUR 10mm insider Series B. The Norwegian developer of zinc-air batteries last raised an EUR 7mm Series A in 2005, and plans on raising an EUR 30mm round next year, according to VWire.

[Self-promotion alert] Very pleased to share the announcement acknowledge the scoop by Jonathan Shieber of Venture Wire today, that Advent Solar has raised a $70mm Series D, led by ZBI Ventures (the private equity and venture investment subsidiary of Ziff Brothers Investments), with participation by other new investors Sun Mountain Capital and Globespan Capital Partners, and also including existing investors Battery Ventures, EnerTech Capital, @Ventures, New Mexico Co-Investment Partners and Firelake Capital. The bulk of the financing will be used to expand the company's capacity from 25MW to approximately 70MW.

Other deals to note:

• In the last posting, we briefly mentioned Silicon Valley Solar has acquired NuEdison in a combination of solar concentrator plays. Today comes word that facilitating this acquisition was a $10.2mm round of financing led by Bessemer Venture Partners.
  

• Traffic prediction startup TrafficCast has raised a $2mm Series A led by Phenomenelle Angels Fund I LP and NEW Capital Fund LP. Women Angels and a syndicate of individuals also participated in the round. Anything that reduces the number of idling engines stuck in traffic is a good thing...

• Smart sprinkler system manufacturer Cyber-Rain has raised an undisclosed amount of financing from Momentum Venture Management.
  

• Also, the Cool Earth Solar convertible note financing we referenced back in May is revealed by Ed Gunther to be now closed at "almost $1 million"... And it's interesting to note the money Google is putting into RechargeIT and PHEVs.

Sector updates:

• Biofuels are getting mixed coverage these days... Corn-based ethanol won't be profitable after 2008?... Don't tell these guys... Fascinating to note that the oil giants' reputations may be lower than the tobacco industry, according to the SVP of Technology at ConocoPhillips... Plus -- confusion at the pump?

• Solar: Solar industry to continue amazing growth path -- grid parity by 2014? So says RBC Capital Markets... Green buildings: Nice overview of cutting edge approaches here... Smart grid: Nice two-part article (part 1 / part 2) on some of the looming changes to the grid.

Other news and notes: Here's part two of the interview with Erik Strasser that we mentioned last week, including a very good argument in favor of thesis-driven investing... Cleantech is "old stuff"? Sure, and those grapes were probably sour, too... It's tempting to be skeptical of all of the breathless coverage about "free energy" from magnets these days (thanks, Steorn), but perhaps with so much smoke there's a little fire of some kind -- although certainly there's no such thing as free energy, maybe some useful mechanical efficiency gains are hidden in these kinds of results... Finally, here's a pretty good point.