Process*: Simple sugars—either derived from breaking down tough, cellulosic feedstocks or from sources such as sugarcane—are reacted over solid catalysts to remove the oxygen locked inside their molecules and form high-energy hydrocarbons. Like crude run through traditional refineries, raw sugar feedstocks are separated to create the range of molecules in the fuels we know as gasoline, diesel and jet.
Bottom Line: Green incarnations of today’s fuels are the holy grail, but until cellulose can be cheaply converted to simple sugars, domestic potential will be limited. Virent hopes to have its gas in car tanks by 2012.
Innovators: Virent (backed by Shell and Honda)
Freshwater Usage:** None
Energy Yield***: 100%

Process*: Scientists have genetically engineered algae not just to turn CO2 into oil, but to continuously excrete that oil directly into the surrounding water. Since oil floats, harvesting it becomes simple work compared with the energy-intensive drying and extraction traditionally used for typical algae, which store oil within their cell walls. As with second-generation methods, the oil can then be processed into biodiesel.
Bottom Line: If they can perform at scale, these mutant algae may well be game changers. Synthetic Genomics hopes to have commercial amounts of biodiesel on the market within five years, though no plants have been built yet.
Innovators: Synthetic Genomics
Freshwater Usage:** None
Energy Yield***: 103%

* May vary slightly from company to company.
** Gallons per gallon of fuel, based on early projections; amount may vary depending on final production process.
*** Compared to a gallon of gasoline.

Honda Motor Co. is backing hydrogen power for the cars of the future, a stance at odds with the Obama administration’s decision to drop automotive fuel-cell technology in favor of battery-run vehicles.

“Fuel-cell cars will become necessary,” said Takashi Moriya, head of Tokyo-based Honda’s group developing the technology. “We’re positioning it as the ultimate zero-emission car.”

Honda, the only carmaker leasing fuel-cell autos to individuals, opened a production line last year in Tochigi prefecture to make 200 FCX Clarity sedans. The Energy Department sought to eliminate hydrogen-station funding and instead lend $1.6 billion to Nissan Motor Co. and $465 million to Tesla Motors Inc. to build electric cars, and give $2.4 billion in grants to lithium-ion battery makers.

“Honda has a propensity to think very long term,” said Ed Kim, an analyst at AutoPacific Inc. in Tustin, California. “It’s also part of the company culture that if they’ve made a decision they think is correct, they’ll really stick with it.”

Honda isn’t alone. Toyota Motor Corp., Daimler AG, General Motors Corp. and Hyundai Motor Co. say hydrogen, the universe’s most abundant element, is among the few options to replace oil as a low-carbon transportation fuel.....

Hydrogen holds tremendous potential as a clean energy source, but there are still significant hurdles to overcome before it becomes a legitimate option for cars and trucks. Two of those issues are storage and transportation of the fuel, particularly when large high-pressure tanks aren't an option. A new creation called Powerpaste, developed by a research team at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials in Dresden, Germany, could potentially answer those questions.

According to the Institute, Powerpaste is made up of magnesium hydride (created when magnesium powder is combined with hydrogen), an ester and a metal salt. A plunger pushes the paste out of its container, water is added and hydrogen is released. Half of the hydrogen is released from the magnesium hydride and the other half comes from the water. The resulting hydrogen can then be used to generate electricity using a fuel cell.

Because both parts of the mixture release hydrogen, the combination of Powerpaste and water can reportedly store more hydrogen than standard high-pressure tanks and is 10-times more dense than today's batteries. And since both the paste and the required water are easy to carry in cartridges or canisters and don't pose a dangerous threat in high temperatures, no significant infrastructure is needed to make the fuel source available to potential customers.

The Fraunhofer Institute suggests that electric scooters and motorcycles are an ideal initial test for its Powerpaste, and it plans to launch a production plant this year to produce up to four tons of the fuel per year. If that's successful and everything works out as well as they hope, the researchers hint that Powerpaste could be useful for other sectors, presumably including automobiles.

Of course, hydrogen has other hurdles to overcome, chief among them revolving around a good way to capture hydrogen in the first place, but we're certain researchers are working to resolve those questions, too.

Shell Hydrogen will permanently close all seven of its California pumping stations immediately, the company confirmed this week. It will no longer operate light-duty hydrogen stations in the U.S., and represents another blow to the struggling hydrogen car market in the only state where the fuel is widely available at all.

The outlet Hydrogen Insight first reported the news on Thursday. Shell had, until recently, operated seven of the 55 total retail hydrogen stations in California, per the Hydrogen Fuel Cell Partnership (H2FCP). That makes this a blow, but not apocalyptic news for the (small) hydrogen community.

Unfortunately, the reason why Shell is closing up shop should give Toyota Mirai, Hyundai Nexo, and Honda Clarity Fuel Cell owners—God bless 'em—even more cause for concern. In the letter announcing the closure, Shell Hydrogen Vice President Andrew Beard said they were shutting them down "due to hydrogen supply complications and other external market factors." It's not hard to see what Beard is referencing here.