VentureBeat

If, like us, you took some time off during the past week, you’ve missed a few cleantech news items. To help out, we’ve assembled a quick catch-me-up on a few interesting or significant stories:

1) Martin Tobias out at Imperium Renewables
2) The grand plan for solar in 2050
3) Companies prove cleantech can stand alone
4) Ethos plans ethanol production in South America
5) Asphalt used as a cheap solar cell
6) New Tesla CEO posts open letter

Martin Tobias out as CEO of Imperium Renewables — As one of the nation’s most heavily-funded privately-funded biofuels company, Imperium Renewables has gotten plenty of press — both positive and negative — for its plans to produce ethanol in a struggling coastal town in Washington. However, nobody was expecting the company to suddenly announce the departure iCEO Martin Tobias. No reason has been given (or ferreted out by reporters). Tobias, a veteran of Ignition Capital and dotcom-era company Loudeye, was replaced by John Plaza, the company’s founder. We spotted one small clue that the company didn’t plan ahead for the departure: It still lists Tobias as its CEO.

The grand plan for solar in 2050 — Scientific American has a sprawling feature piece on the potential future of solar energy in the United States. A few soundbites: 69 percent of all electricity in the US could be supplied by solar by 2050. For this, a new DC (direct current) transmission network may need to be built; both photovoltaics and solar thermal will need to be used; and finally, the government may need to subsidize more than $400 billion of construction to get such a network off the ground.

German companies prove renewable energy can stand alone — Researchers at the University of Kassel teamed with several German power companies to study the potential of renewable energy sources — hydro, solar, wind and others — to power an entire country. A grid of 36 plants was connected to show, in miniature, that such sources can effectively work together. Now the problem for Germany (and other companies) is scaling the output to meet demand. Much more detail on the study is available at Biopact.

Ethos will produce its ethanol in South America — An ethanol production company backed by venture capitalists in the United States plans to head south to make its margins. Ethos, a Cambridge, Mass. company, is considering both Latin America and the Carribean for establishing biofuel facilities, and plans to use sugar as its feedstock, according to VentureWire. The company is funded by Khosla Ventures and GreatPoint Ventures.

Power from roadways to heat and cool buildings — A Dutch company called Ooms Avenhorn Holding has worked out a method of piping water underneath roads, which tend to get hot from the sun, then storing it in caverns to warm buildings in cooler months — in effect, turning roads into a low-efficiency but very cheap solar thermal generator. The system, which uses a lattice of pipes beneath asphalt, can also be used to de-ice roads. More details at the San Jose Mercury.

Tesla’s new CEO sends open letter to customers — Ze’ev Drori, the new CEO at Tesla Motors, sent an open letter to customers over the holidays via the company blog. Not everything in the letter is reassuring: Drori admits that, due to Tesla’s production strategy, “We don’t yet know when each car will be built or how many cars will be completed in calendar year 2008.” Drori’s predecessor, Martin Eberhard, was likely forced out due to internal disagreements centering around delays in production. Tesla also recently announced that it would be using a less-effective transmission for its initial production run. [Update: The company says this transmission will be used for only a portion of the initial production. See below]