President Barack Obama's energy and climate assistant says the United States needs a unified federal standard for regulating greenhouse gas emissions from cars and trucks — and automakers, perhaps surprisingly, aren't that upset by the idea. That's the gist of a report from the Washington Post, detailing comments made Sunday by Carol Browner, who is head of a newly-created White House position to coordinate energy, environment and climate change policies across federal agencies. The idea is to form a unified policy that combines Environmental Protection Agency emissions regulations and the Department of Transportation's mileage standards, the Boston Globe reports. Browner laid out the plan at the Western Governors Association meeting in Washington, D.C. Part of the new regime would involve the cap-and-trade legislation that President Obama wants Congress to pass this year, according to the Post, which cited unnamed White House sources. Obama has said he wants a carbon cap-and-trade system to help reach a goal of cutting the nation's greenhouse gas emissions to 80 percent below 1990 levels by 2050, and the White House intends to release a budget this week that includes projected revenues from auctioning off emissions allowances under such a system, the Post reported. You might think that automakers would be upset at the idea of new federal regulations, but according to the Post, spokespeople from General Motors and the Alliance of Automobile Manufacturers trade group reacted positively to Browner's remarks, saying they would provide more certainty. Perhaps that's because they would rather see a federal standard in place than state-by-state regulations. California's plan to regulate vehicle greenhouse gas emissions was rejected by the Bush administration in 2007, but the EPA said earlier this month that it would reconsider that decision. That could open the door to an additional 13 states that want to set tail-pipe emissions limits stricter than current national standards (see Obama to Seek to Allow California, Other States, to Impose Emission Standards). Automakers also might be hoping a unified policy will ease President Obama's push to make cars 40 percent more fuel-efficient by 2020, with improvements set to start with 2011 models (see Obama: Cars Need to Improve Gas Mileage by 40%) Or perhaps it's because, with billions of federal bailout dollars in their pockets and their hands out for billions more, companies like GM and Chrysler aren't in a position to second-guess the government's efforts to push them to make their vehicles greener (see U.S. Automakers Get Federal Bailout).

Fool’s gold is an apt symbol for the future of sustainable energy, though not (we hope) in the obvious sense. It’s a case of less being more. There’s a growing recognition that many sustainable energy technologies are not always produced sustainably, particularly when it comes to key materials like platinum, lithium, indium and high-grade crystalline silicon. It comes down to scarcity, toxicity, costly processing or a combination. Researchers are beginning to look for less toxic, earth-abundant materials to generate and store energy. MIT’s Tonio Buonassisi is leading an effort to systematically search for safe, abundant semiconductor compounds for photovoltaics. Efforts like this aim to produce energy systems that have long-lasting supplies of raw materials, have minimal negative impacts on the environment, and lower the cost of producing clean energy. Researchers from UC Berkeley have taken the concept a step further. They’ve produced a study that shows that if our goal is to use photovoltaics to meet a large portion of our electricity needs, some of these abundant compounds are the best way to go based simply on the economics. Here’s where fool’s gold, which has fooled gold hunters for ages with its similar color and sheen, comes in. The Berkeley study looked at 23 compounds for the total potential electricity that can be generated from systems made with the known reserves and cost per watt. They combined the results to identify materials with the greatest long-term potential for generating electricity. The clear winner was pyrite, or fool’s gold. The runner-up was amorphous silicon, already widely used in the photovoltaics industry. The study counters the prevailing assumption that the best way to push photovoltaics into the mainstream is to improve device efficiency without increasing costs. We also need to look at lowering costs without sacrificing too much efficiency. It turns out that less efficient but markedly cheaper materials can be a better route to making solar a dominant source of energy. The study should bring encouragement to the many researchers working to make dye-sensitized, organic and nanostructured solar cells commercially viable. Maybe it’ll also spur a renewed interest in making solar cells from fool’s gold. Eric Smalley is editor of Energy Research News. He has written about technology since 1987 and has freelanced for many publications including Discover, Scientific American, Wired News and The Boston Globe on topics ranging from quantum cryptography to global warming.