Harnessing Energy Never Looked So Good

06/01/2011 |

New improvements in solar and fuel cells are driving innovation while lowering costs.

As interest in renewable energy grows, so do advancements that increase performance and decrease costs. Boosting the technology in these power sources expands current applications and brings their benefits to a wider range of consumers.

Solar cells: Did you know that light can generate magnetic effects similar to electricity? Neither did researchers until recently. An experiment at the University of Michigan (UM) revealed that when light travels through a material that doesn't conduct electricity, the light field produces magnetic effects 100 million times stronger than previously expected.

This means that an "optical battery" could be created, leading to solar power without traditional semiconductor-based solar cells.

"In solar cells, the light goes into a material, gets absorbed, and creates heat," explains Stephen Rand, a UM physics professor. "Instead of the light being absorbed, energy is stored in the magnetic moment. Intense magnetization can be induced by intense light, which is ultimately capable of providing a capacitive power source."

The new method could drive down solar costs. "To manufacture modern solar cells, you have to do extensive semiconductor processing," says William Fisher, a UM doctoral student. "All we would need are lenses to focus the light and a fiber to guide it."

Researchers predict they can achieve 10% efficiency in solar cells (meaning 10% of the light can be converted) with the improved materials, making them comparable to today's commercial-grade cells.

Hydrogen fuel cells: Because platinum in catalysts is necessary to produce electricity in a hydrogen fuel cell, applications have been limited. To drive down costs in the industry and improve efficiency and lifespan, researchers have been looking for platinum alternatives. A breakthrough from the Los Alamos National Laboratory shows that non-precious metals can serve as catalysts.

Scientists found that a combination of carbon, iron, and cobalt – inexpensive and abundant materials – yields high power output, good efficiency, and promising longevity. Not only can they replace platinum, which costs almost $1,800 per ounce, but they hold up favorably during on-off cycles. They also don't produce hydrogen peroxide, a byproduct of platinum reactions that reduces power output.

"The encouraging point is that we have found a catalyst with a good durability and lifecycle relative to platinum-based catalysts," says Piotr Zeleny, co-author of the study. "This is a zero-cost catalyst in comparison to platinum, so it directly addresses one of the main barriers to hydrogen fuel cells."

The technological advance opens up new areas for fuel cells, replacing current power sources in everything from personal data devices to cars.


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