Advances could at last make the high-energy batteries practical.
Venture-capital investing remains slim, but some momentum is building.
Ksplice uses new technology to build security updates for Linux that can be installed without restarting.
Startup Enphase Energy is shrinking DC-to-AC inverters to extract more juice from solar panels.
The secretary of energy talks with Technology Review about the future of nuclear power post Yucca Mountain and why fuel-cell cars have no future.
Mascoma has announced several advances that may lead to a cheaper, more efficient process to turn biomass into ethanol.