Tesla Motors and Imperium Renewables both made cuts to their employee roster last week.

Tesla, a maker of electric cars, cut three senior executives and more than a dozen other employees, The San Jose Mercury News reported Thursday evening.

The ousting, which included two manufacturing vice presidents, wasn't because of cash flow, the Mercury News reported.

"This is about accountability," Darryl Siry, Tesla's vice president of sales, marketing and services, told the paper. He then proceeded to point out 39 job openings listed on the company's Web site.

Biofuels company Imperium Renewables also said it "reduced its corporate workforce" to "address short-term challenges and ensure the company's long-term growth," according to the Seattle Post-Intelligencer.

The news comes a week after the Seattle Wash.-based company announced it was delaying its plans for an initial public offering, citing unfavorable market conditions, and within a month after Martin Tobias announced he had left his roles as CEO and chairman.

Here's a roundup of some of the other happenings last week:

Green Investments Rise Alongside Temperatures

Green investment is skyrocketing as climate-change warnings grow ever more dire, according to several reports released this week.

Venture capitalists invested $3.4 billion in 222 renewable-energy deals during 2007, according to Greentech Media's Venture Power Report, released Friday (see a preview in Cleantech Investing post). That's up from $2.3 billion in 2006 and $800 million in 2005, according to the report.

Most of those deals involved solar companies, which garnered $1.05 billion in 71 deals in 2007, nearly triple the $360 million in venture deals such companies nabbed in 2006 and the $150 million they netted in 2005, according to the report. Biofuels companies also made a strong showing, raising $796 million in 44 deals during 2007.

Meantime, a report released Wednesday by the Worldwatch Institute found that climate change is dramatically altering the world economy, creating a flurry of new business opportunities (see Climate Change Redrawing World Economy, Worldwatch Says). According to the 278-page report, a total of about $66 billion was invested in renewable energy in 2007, up from $52 billion in 2006.

And an Earth Policy Institute report published Thursday indicates the need for innovation is stronger than ever. According to the report, the global average temperature in 2007 was 58.5 degrees Fahrenheit (14.73 degrees Celsius), making it the second-warmest year on record, after only 2005.

It also was the hottest year ever for the Northern Hemisphere--at least since scientists began keeping records in 1880. Temperatures in the North averaged 59.1 degrees Fahrenheit (15.04 degrees Celsius), more than a degree warmer than the average of years from 1951 through 1980.

The bad news is good for greentech, however.

According to research firm Energy Insights, technologies such as renewable energy, energy-efficiency setups, carbon-trading software and IT systems to measure and manage companies' carbon footprints are among those that stand to benefit most in 2008.

EEStor Inks Deal with Lockheed Martin

Cedar Park, Texas-based EEStor signed an exclusive international deal with defense contractor Lockheed Martin, EEStor said Wednesday. Under the new deal, Lockheed Martin will integrate EEStor's ceramic batteries into military applications. EEStor claims its batteries potentially have 10 times the energy density of lead-acid batteries at half the price (see Earth2Tech post and VentureBeat post). EEStor plans to begin mass production by the end of this year (see Clean Break post).

Biofuels Firms Suffer, Turn to New Feedstocks

Biofuel companies have seen their margins squeezed in the past few months as prices for the crops used to make the fuels have gone up while biofuels prices have gone down (see Ethanol Margins Suffer and Ethanol's Tough Times Continue).

Aside from the Imperium news, U.S. Bioenergy of America filed for bankruptcy this week.

But that doesn't mean biofuel companies aren't pushing on. In particular, companies are announcing work in new feedstocks they hope will help give them an edge and change market conditions.

On Wednesday, German carmaker Daimler said it teamed up with Archer Daniels Midland and Bayer CropsScience to develop biodiesel from jatropha.

The group is hoping to create production and quality standards for creating biodiesel from the hardy, drought-resistant plant, which produces seeds containing up to 40 percent oil.

Others are turning to trash for potential solutions.

On Friday, Greenbelt Resources said by early summer it would start construction on a new facility to turn waste such as expired beverages into ethanol.

The Burnsville, Minn.-based company said it needed the extra manufacturing space because the Master Recycling Center increased an earlier order of 2 million gallons of ethanol per year to 5 million gallons per year.

Greenbelt Resources incorporates ethanol production facilities into existing recycling plants.

On Tuesday, BlueFire Ethanol Fuels announced it had closed $15 million from Quercus Trust to turn waste into ethanol. BlueFire plans to use cellulosic waste that would have otherwise ended up in a Southern California landfill.

And Novus Energy and Oxford Catalysts said Wednesday that they are building a small pilot plant to produce 100 gallons of fuel per year from organic waste.

In other biofuel news, Diversified Energy Corp. and researchers at North Carolina State University said Wednesday that they've been able to produce a biofuel very similar to unleaded gasoline from a wide variety of oils.

Trashing Energy

Biofuel companies aren't the only ones that want to turn trash into treasure.

On Friday, start-up Ze-gen said it closed $2.5 million in venture debt from Pinnacle Ventures. Boston, Mass.-based Ze-gen uses gasification technology to convert municipal waste into synthetic gas and electricity.

Ze-gen said it expects to start construction on a full-scale commercial facility by the end of 2008.

In total Ze-gen has raised more than $8 million in financing.

On Tuesday, EnerTech Environmental said it had snagged $42 million in a second round of funding to develop five renewable energy plants that will convert not-so-pleasant wastes, such as sewage sludge, into renewable energy (see EnerTech Grabs $42M to Turn Sewage Into Energy).

The investment round was coled by the Masdar Clean Tech Fund and Citigroup's Sustainable Development Investments unit..

The funding brings EnerTech's total venture capital to about $57 million.

The news supports predictions from Michael Butler, CEO of Cascadia Capital, and Jon Bonanno, president of Principal Power and chairman of the Keiretsu Forum's Cleantech Investment Committee, that waste-to-energy technologies would be hot this year (see Three Financiers Foretell 2008).

Finally, the U.S. Environmental Protection Agency handed out awards this week to projects that have turned methane from landfills into clean energy.

Nationwide, there are about 435 such projects, which provided more than 10.5 billion-kilowatt hours of electricity in 2007, according to the EPA.

Winners included the Greentree High Btu Landfill Gas Project in Kersey, Pa., and the Iris Glen Landfill Gas to Energy Project in Johnson City, Tenn.

Landfills might look like nothing more than heaps of garbage, but there are items of importance to be found in them.

According to Ze-gen, industry data suggests there is more than 50,000 megawatts of latent energy in the United States waiting to be harvested from landfills and other human waste streams.