A Tour of the U.S.'s Clean Energy Future [Slide Show]

The third annual ARPA-E summit showcases potentially transformative energy technologies

CONSTANT WIND: High in the stratosphere the wind is always blowing, supplying a steady source of energy. But how to harness it? Makani Power's carbon-fiber "kite" would circle high in the sky, harvesting incessant wind power and transmitting it via its tether to the ground... © David Biello
ARTIFICIAL PHOTOSYNTHESIS: Sunlight kicks off a chemical reaction that splits water, releasing oxygen and hydrogen, which can be used as a fuel--just as plants use sunlight to split water to make carbohydrates. Sun Catalytix hopes to turn its sunlight-and-water system into a cheap source of power for homes... © David Biello
SEMICONDUCTOR REFRIGERATOR: Without hydrofluorocarbons or compressors, Sheetak technology employs semiconductors to refrigerate--and may enable cheap cooling for the poorest people in developing countries. "It will enable people who never had access to refrigeration in their lives to use refrigeration to preserve food and medicine," said ARPA-e director Arun Majumdar, noting the company has a deal with a distributor in India to make such coolers... © David Biello
FLEXIBLE BATTERIES: Flat, 100-square-centimeter rechargeable cells equivalent to one AA battery power this flashing vest and LED headlamp, stylishly modeled by the black mannequin. FlexEl also makes a one-meter-square "battery cloth.".. © David Biello
Advertisement
BETTER BIOREACTORS: Glass manufacturing giant Corning is working on technology to improve algae growth in so-called bioreactors. Quantum dots shift incoming sunshine to wavelengths the human eye perceives as red, which is also the best wavelength for photosynthesis... © David Biello
SOLAR-THERMAL ENGINE: This Rankine cycle engine from Cyclone Power Technologies can run on everything from sunshine to syngas derived from garbage at temperatures as low as 260 degrees Celsius. The engine employs heat—or waste heat—from these sources to create the steam that powers the engine... © David Biello
MICROBIAL FUEL CELL: Graduate students at the Wyss Institute for Biologically Inspired Engineering at Harvard University explain their microbial fuel cell, a method for producing electrofuels, to ARPA-E founding director Arun Majumdar... © David Biello
CAPTURING CARBON: "The U.S. has the largest reserves of coal in the world and we ought to be able to use it in a sustainable way," ARPA-E director Arun Majumdar argued. To that end, the agency is funding work on making carbon capture and storage cheaper so that it can be implemented at coal-fired power plants... © David Biello
Advertisement
STORING SUNSHINE: ARPA-E is funding so-called electrofuels--liquid fuels derived from microbes employing waste carbon dioxide and electricity. Here Geobacter lives in a tank of electrodes, taking in CO2 and water and spitting out hydrocarbons for either transportation or chemicals... © David Biello
ALTERNATIVE FUELS: Biofuels remain one of the most promising options to reduce oil use in another transportation sector—aviation. The oil derived from the weedy flowering plant known as c amelina can be refined into a bio–jet fuel that has already been used to power commercial and military flights... © David Biello
IMPROVED INTERNAL COMBUSTION: One of the winners of the U.S. Department of Energy's America's Next Top Energy Innovator challenge, Umpqua Energy injects hydrogen into regular gasoline in order to boost the power that today's internal combustion engines can deliver... © David Biello

Newsletter

Get smart. Sign up for our email newsletter.