Tag Archives: solar energy

Tomorrow and Friday: BSR live blogs the BERC Innovation Expo and Energy Symposium

At some point during the last year and a half, you’ve probably found yourself thinking: “I really wish the BSR Blog team would live blog a campus event.” Well, the wait is officially over. Tomorrow, Oct. 20 and Friday, Oct. 21 we’ll be posting live updates from the BERC Innovation Expo and Energy Symposium, an exciting event showcasing cutting-edge energy research from UC Berkeley and beyond. If you can’t make it to the events in person (tickets are selling out fast), join us here on our website from 6 – 9 PM Thursday and 9 AM – 6 PM Friday, and we’ll make sure that you don’t miss a thing!

Should Americans make stuff? Do we really need to ask?

John Henry. Paul Bunyan. Rosie the Riveter. Many of the American icons of the past have something in common: they made things. And for a long time, the rest of the country followed suit, becoming the world’s leading producer of manufactured goods throughout the 20th century.

Rosie the RiveterToday, the story has changed. Manufacturing jobs are increasingly being outsourced—and not just because other countries offer cheaper labor. Positions requiring both high and low skilled workers have flowed steadily out of the country for the last few decades, to the point that China and Germany have recently surpassed the U.S. as the world’s top exporters.

An argument can be made that there is nothing fundamentally wrong with having less domestic manufacturing. Indeed, American corporations like IBM are often applauded for transitioning from manufacturing to services because of the opportunity to earn higher profit margins. This sentiment is even more visible at the level of individuals: doctors, lawyers and movie stars are among the wealthiest members of society, even though they don’t make anything tangible. If providing services works for individuals and corporations, it would seem that the U.S. could likewise pay its bills (and then some) as a global service provider in return for manufactured goods.

Reaching for the sun

Most of the time, doing something 28% efficiently is nothing to be proud of. But in photovoltaics, it is good enough to set a new world efficiency record—and earn the company that made the record-setting devices millions of dollars in venture capital.

In this case, the lucky company is Alta Devices, which until recently held a low profile in the crowded solar industry. For the last few years, Alta has been quietly developing a novel process for cheaply manufacturing ultra-efficient solar cells. Their hard work appears to be paying off, because last month the company reported that they can make cells that are 28.2% efficient at converting solar energy into electricity. This beats the previous record by more than one percent, a wide margin by the solar industry’s standards.

Alta’s solar cells are made of a semiconducting material called gallium arsenide. Because this is a relatively expensive material, most solar companies use cheaper, less efficient alternatives such as silicon. But Alta came up with a transfer process that allows them to lay gallium arsenide layers that are only one micron thick (about 100 times thinner than a sheet of paper) on each cell.  The thin layers don’t use up much material so they don’t cost very much, but they still generate as much electricity as a thicker layer would.  The company’s goal is to generate electricity at a cost of under 50 cents per watt, which is about twice as cost-effective as the current state-of-the-art.

Hydrogen production with disorder-engineered nanoparticles

One great example of nanomaterials that can address environmental problems is photocatalytic water splitting, which produces hydrogen gas through a chemical reaction that consumes only water and sunlight. This eco-friendly hydrogen can power zero-emissions fuel cells found in cars and a number of other emerging clean technologies. The goal is to replace conventional methods of manufacturing hydrogen, which generally consume fossil fuels and/or large amounts of electricity.

In photocatalysis, materials like titanium dioxide (TiO2) nanoparticles catalyze water splitting by absorbing light and transferring the light’s energy to nearby water molecules. In turn, the water breaks apart into its constituent elements, hydrogen and oxygen. Because of the absorption properties of TiO2, artificially generated ultraviolet light is required for the reaction to proceed efficiently. However, in a recent publication in Science, a group of Berkeley Lab researchers have shown that a slightly modified version of TiO2 nanoparticles can split water under natural sunlight.