A new joint venture research work at Stanford and SLAC National Accelerator Laboratory, supported by Department of Energy and DARPA has come up with a new solar energy conversion process that can potentially double the efficiency of solar cells. Stanford engineers have discovered this new and totally different process to harvest energy from sun.

Way to make the cells more efficient

The best way to increase the efficiency of the solar cells is to somehow harvest the wasted heat energy and to keep up and utilize the high temperatures which are reached during conversion. Utilizing the existing technology along with utilizing both the photovoltaic and thermal conversion techniques is what is needed.

Breakthrough process

In the new process, the semiconducting material was coated with a thin layer of caesium which allowed the material to use both the light and heat of sun to generate electricity. Though this is not actually standardized photovoltaic mechanism happening, this is a photovoltaic-like response happening best at very high temperatures. The new process is called Photon enhanced thermionic emission (PETE).

Conceptual breakthrough

Nick Melosh, Assistant Professor of Material Science & Engineering, leading the research group says, “This is really a conceptual breakthrough, a new energy conversion process, not just a new material or a slightly different tweak.” The new process is called ‘photon enhanced thermionic emission’ (PETE). This process is expected to reduce solar energy production cost competitively with oil.

Weakness harnessed as strength

What is the weak point with most silicon cells – losing efficiency in higher temperatures – is the strong point of PETE process as the devices working with PETE process works best at temperatures as high as 800 degree Celsius. The PETE device utilizes the light and high temperatures produced are usable and dumped in the thermal conversion process.

Peaking efficiency

PETE process has the potential to almost triple the existing system efficiency as demonstrated in solar farms in Mojave Desert in Southern California. Melosh says, “PETE process has two really big benefits in energy production over normal technology.”

Affordable process

The tam claims that PETE process needs economical and easily available materials only – making thus the power harvested via this process very affordable. The conversion into PETE process is also relatively inexpensive as they are being designed to be bolted to present structures.

Research team goal

The research team published their paper in ‘Nature Materials‘ after demonstrating the process successfully. The team is experimenting on various semiconductors like gallium nitride and gallium arsenide and other such materials. Even a 10 % boost to the existing solar efficiency is a 50% overall hike and very welcome for solar cell power generation.

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