Peter N. Saeta

Professor (1995)
PhD Harvard
Ultrafast physics, semiconductors, photovoltaics, energy and environment
Keck 1231
909-607-3939 (office)
909-621-8024 (department)
909-621-8887 (fax)

A hot spot in a conventional solar panel

Photovoltaics are the fastest-growing renewable energy source in recent years and have the potential to supply a significant fraction of our electricity needs. As prices of conventional panels have dropped and the efficiency of their constituent cells improved, a problem inherent in the design of conventional panels has grown more pressing. When a portion of a cell is shaded, it cannot provide as much current as the surrounding fully illuminated cells to which it is connected in series. To generate additional current, the cell goes into reverse bias, which means that instead of generating power, it absorbs power from the other cells and heats up. A lot! The image shows a hot spot forming in a partially shaded cell while conducting a standard test of panel performance.

Recent research explores alternate strategies for wiring panels and using module-based electronics to operate panels in a way that prevents hot spots from forming. The successful deployment of such panels could allow more roof area to be used productively for electricity generation and improve the safety of photovoltaic installations by preventing hot-spot-induced fires and enabling immediate cut-off of high voltage.

Recent Publications

Peter N. Saeta, Harry A. Atwater, Vivian E. Ferry, Jeremy N. Munday, and Domenico Pacifici

How much can guided modes enhance absorption in thin solar cells?

Optics Express 17 (2009) 20975-20990.

William Steven Kolthammer, Dustin D. Barnard, Nicole J. Moore, Aaron D. Edens, Nathan A. Miller, and Peter N. Saeta

Harmonic generation in thin films and multilayers

Physical Review B 72 (2005) 045446.
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