Bubble tracking could lower solar-concentrator cost

Nov. 5, 2012
A group at the École Polytechnique Fédérale de Lausanne has developed an optofluidic waveguide coupling mechanism in which focused light heats liquid in a waveguide to form a bubble of vapor that scatters the incoming sunlight into the waveguide, which carries the light to a concentrating photovoltaic cell.

Concentrating solar photovoltaic (PV) systems cut system costs by reducing the area of PV cells for a specified electrical output, but the precise mechanical tracking systems needed to keep a concentrator aimed at the sun can raise the system cost, to little advantage. As a result, researchers are looking at nonmechanical ways to finely track the sun (coarse tracking could still be left to a lower-cost mechanical tracker).

A group at the École Polytechnique Fédérale de Lausanne (Lausanne, Switzerland) has developed an optofluidic waveguide coupling mechanism in which focused light heats liquid in a waveguide to form a bubble of vapor that scatters the incoming sunlight into the waveguide, which carries the light to a concentrating PV cell. The experimental efficiency of a system coupling laser light through an off-the-shelf axicon lens pair into a methanol-containing waveguide was greater than 40%. Two lasers were used: one emitting at 460 nm to represent the visible part of the solar spectrum, and an infrared (IR) laser diode to simulate the IR spectral portion. When focused on the IR-absorbing glass that helps form the waveguide, the light produces a bubble that varies between 160 and 300 μm in diameter for IR power between 40 and 100 mW. The bubble-tracking technique could reach at least 90% efficiency with better optics, say the researchers. Contact Volker Zagolla at [email protected].

Sponsored Recommendations

How to Tune Servo Systems: Force Control

Oct. 23, 2024
Tuning the servo system to meet or exceed the performance specification can be a troubling task, join our webinar to learn to optimize performance.

Laser Machining: Dynamic Error Reduction via Galvo Compensation

Oct. 23, 2024
A common misconception is that high throughput implies higher speeds, but the real factor that impacts throughput is higher accelerations. Read more here!

Boost Productivity and Process Quality in High-Performance Laser Processing

Oct. 23, 2024
Read a discussion about developments in high-dynamic laser processing that improve process throughput and part quality.

Precision Automation Technologies that Minimize Laser Cut Hypotube Manufacturing Risk

Oct. 23, 2024
In this webinar, you will discover the precision automation technologies essential for manufacturing high-quality laser-cut hypotubes. Learn key processes, techniques, and best...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!