The Year in Energy

At the end of 2010, GM and Nissan introduced their long-awaited electric cars, the plug-in hybrid Chevrolet Volt and the all-electric Nissan Leaf. If these are successful, they could bring sweeping changes to the automobile industry, which has relied almost exclusively on petroleum to power its cars. But whether electric vehicles become popular depends on improving the technology, especially by developing better batteries.

Better Batteries

The Volt and the Leaf use advanced lithium-ion batteries that the automakers calculate will last many times longer than the batteries in your laptop. But they’re expensive, and the distance they can power a car is limited. In the near term, better electrodes that store more energy using less material could help, such as the silicon ones Panasonic is rolling out (Tesla to Use High-Energy Batteries from Panasonic). And a new test could allow researchers to quickly sort through combinations of electrodes and electrolytes to find ones that will last for the life of a car (A Quicker Test for EV Batteries).

Over the long term, novel battery chemistries such as lithium-sulfur offer potentially much greater energy storage at a lower cost than lithium-ion batteries (Packing More into Lithium Batteries). And a new approach that uses fluid electrodes rather than solid ones could help break through the energy storage limits that make it hard for electric cars to compete with gas-powered ones (New Battery for Cheap Electric Vehicles).

Cheaper Solar Power

In many parts of the country, electric cars will essentially be coal-powered, running on electricity generated by the fossil fuel. Electric power is highly efficient, so they will emit less carbon dioxide than conventional cars. But if electric cars are to achieve their true potential for reducing pollution, they will need to use more renewable energy.

Solar power saw significant advances this year, as conventional-solar-panel makers cuts costs and improved efficiency and laboratories rolled out advanced prototypes. China was a big part of the story, as its manufacturers refined their designs (Solar’s Great Leap Forward).

In the United States, government loan guarantees helped increase investment in solar technology, including by thin-film-solar makers such as Abound Solar (Solar Cell Maker Gets a $400-Million Boost). It is not clear, however, what will happen to federally supported industries when the money from the 2009 stimulus bill runs out (Cash for Infrastructure). Funding from the new Advanced Research Projects Agency for Energy (ARPA-E) is being used to find cheaper ways to manufacture conventional silicon solar panels (Making More Solar Cells from Silicon).

Meanwhile, laboratories made prototypes of potentially ultra-efficient new kinds of solar panels. Nanostructures help solar panels absorb light, increasing their power output by 30 percent or more (TR10: Light-Trapping Photovoltaics and Solar Cells Use Nanoparticles to Capture More Sunlight). Researchers are finding ways around the inherent physical limitations of semiconductors, demonstrating in a prototype solar cell an effect that allows photons to generate multiple electrons. This approach could increase solar power output by 50 percent (Upping the Limit on Solar Cell Efficiency). A novel approach that uses both heat and light from the sun to make electricity could potentially double the output of solar panels (A New Way to Use the Sun’s Energy).

These prototypes are many years from commercialization, but by increasing the power output of solar panels without greatly increasing the cost to make them, they could reduce not only the cost per watt for solar panels but also the number of solar panels needed and therefore shipping and installation costs—something that will be key for solar to go head to head with conventional power.

To be sure, it will be years before many of these advances work their way into the marketplace. The lack of a comprehensive energy policy in the United States, where many of the innovations are taking place, doesn’t help (Piecemeal Energy Policy Will Still Cut Greenhouse Emissions). And the inability of Congress to pass a budget this year could stifle research and development—the funding of ARPA-E, for example, hangs in the balance (Dim Prospects for Energy R&D).

But if the willingness to compromise that allowed Democrats and Republicans to pass a tax-cut bill at the end of the year continues, there may be surprising progress. Meanwhile, China continues to push forward with plans to lead the world in electric vehicles, providing government incentives to develop the cars and install charging stations. Next year, that ambition will be evident outside China, as Chinese automaker BYD plans to start selling its first electric car in the United States.

By Kevin Bullis,