Hybrid Solar Cells: How university research causes 'green' innovation

Columbia University is pioneering the use of hybrid solar cells to produce heat and electricity simultaneously. 

A close up of a solar cell is seen here.

All major universities have student newspapers. After serving for 17 years as a faculty member at a number of excellent schools, I'm always amazed at the insipid content of these newspapers. Usually, you wouldn't know that the University has a research faculty. The typical articles focus on romance, frats, sports, and tuition hikes. But, today's Columbia Spectator offers a great counter-example. This article makes me proud to be an emeritus Associate Professor of that esteemed university.

Columbia’s Engineering School has one solution for making buildings greener—hybrid solar cells that produce heat and electricity simultaneously.

Huiming Yin, assistant professor of civil engineering and engineering mechanics and creator of the panels, said that the purpose of the project was to create more efficient solar cells.

“We want to increase the efficiency of solar cells in our experimentation so that the solar cells don’t waste so much energy when they absorb sunlight,” Yin said.

This sounds like a great opportunity for graduate students to work on a cutting edge project. Columbia University must smell some intellectual property royalties based on the patents that this research will generate.

The nerds who write for Wikipedia have a strong understanding of the innovation issues revolving around solar cells.

"High-efficiency solar cells are a class of solar cell that can generate more electricity per incident solar power unit (watt/watt). Much of the industry is focused on the most cost efficient technologies in terms of cost per generated power. The two main strategies to bring down the cost of photovoltaic electricity are increasing the efficiency of the cells and decreasing their cost per unit area. However, increasing the efficiency of a solar cell without decreasing the total cost per kilowatt-hour is not more economical, since sunlight is free. (An analogy is that a pound of lead weighs the same as a pound of feathers.) Thus, whether or not "efficiency" matters depends on whether "cost" is defined as cost per unit of sunlight falling on the cell, per unit area, per unit weight of the cell, or per unit energy produced by the cell. In situations where much of the cost of a solar system scales with its area (so that one is effectively "paying" for sunlight), the challenge of increasing the photovoltaic efficiency is thus of great interest, both from the academic and economic points of view. Many groups have published papers claiming possibility of high efficiencies after conducting optical measurements under many hypothetical conditions. The efficiency should be measured under real conditions and the basic parameters that need to be evaluated are the short circuit current, open circuit voltage."

 So, in English ---- Al Gore would be happier if more of our electricity supply was generated by renewables. Even Dick Cheney would consider installing solar panels if the price of installation is low, if the panels generate a lot of electricity and if he can sell back his surplus electricity (production - consumption) back to the grid at a good price. Any innovation that makes panels per square foot more "absorbing" or cheaper to install makes the "green Al Gore" scenario more likely.

In academic economics, there continues to be an active research agenda of examining the current economics of solar panels. Here is Severin Borenstein's study.

California is a hotbed of solar innovation. One prominent example is SPG Solar.

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