Chu adds muscle to clean-energy pitch

Within a year of receiving $24 million from the Department of Energy’s Advanced Research Projects Agency–Energy (ARPA–E), a half dozen of the agency’s 121 high-risk research projects have attracted an additional $100 million in private-sector investment. Energy Secretary Steven Chu said the investments indicate that the business community is keenly interested in commercializing the advanced battery, solar, and wind technologies that ARPA–E, DOE’s newest and smallest R&D entity, began funding in 2010.

Chu and other speakers used ARPA–E’s second annual showcase, held 28 February through 2 March, to rally support for clean-energy policies. “From my experience in California, it is absolutely clear that the green economy is the way to keep America competitive abroad and to provide economic growth and jobs at home,” former governor Arnold Schwarzenegger told the 2000 conference attendees. The US could slash its greenhouse gas emissions by half and close three-quarters of its coal power plants, he maintained, if the nation were to adopt California policies that have brought per-capita electricity consumption in the state down to 40% of the US average, and take up California’s mandate for one-third of electricity usage to be provided by renewable sources beginning in 2020. A third California energy policy, higher vehicle fuel-efficiency standards, has already been picked up at the federal level.

Chu emphasized the need for the US to quickly ramp up its clean-energy investments to meet the competition from China and other nations that are moving more nimbly to become suppliers to the rapidly growing world market for renewable and other nonfossil-fuel energy sources. China, he told attendees, is home to 25 of the 60 new nuclear power plants under construction worldwide; has the world’s highest-capacity, lowest-energy-loss high-voltage transmission lines; and runs the fastest high-speed trains, which travel at 402 kph. China is expected to produce 18–20% of its electricity from renewable sources by 2020, he added.

Competing approaches

Arun Majumdar, whom Chu recruited from Lawrence Berkeley National Laboratory to head ARPA–E, described one program to develop “electrofuels” capable of vastly improving on the 1% efficiency at which sunlight is converted in today’s biofuels. The process uses nonphotosynthetic microbes to digest raw materials such as hydrogen sulfide or hydrogen waste products from oil refining or natural gas production, plus carbon dioxide. The resulting biofuels, unlike ethanol, will hold the same energy content as oil. Researchers funded by ARPA–E at North Carolina State University and MIT already have produced such synthetic oil in the lab, he said, and 13 other teams are working on the process. “It will take 10 to 20 years for [the techniques] to scale, and some of them will drop out. Some of them will be cost-competitive. Eventually the market will pick the winners.”

For electric vehicles, ARPA–E’s “technology agnostic” goals are to double the energy density of today’s lithium-ion electric vehicle batteries while cutting the cost by two-thirds. The program has set up a competition among a half-dozen technology candidates, including all-electron, lithium–oxygen, lithium–sulfur, metal–air, and magnesium-ion cells. “We don’t know which one’s going to work out in the end,” Majumdar said. “Perhaps one or two of them might.”

For improving the nation’s electrical transmission and distribution grid, ARPA–E awardee Cree Research is researching a lightweight replacement for today’s 4500-kg, mostly foreign-manufactured electrical substation transformers. Besides cutting transformer weight by two orders of magnitude, the suitcase-size replacements would be semiconductor-based and would provide smart grid capabilities.