“An important scientific innovation rarely makes its way by gradually winning over and converting its opponents: What does happen is that the opponents gradually die out.”
—Max Planck

Sunlight is everywhere. Not all the time of course, but even places that get a lot of cloud cover still receive a lot of energy from the sun, enough to make solar power a viable alternative to fossil fuels.

That’s why solar energy is one of the main sources of renewable energy being developed today. Along with wind and geothermal, getting energy from sunlight is one of the best ways to provide us with electricity without creating significant greenhouse gas emissions in the process.

Mostly, people think of two types of solar energy. The first is photovoltaic (or solar) panels, where a direct current is generated by a photon hitting a photoelectric cell. The second is concentrated solar thermal (CST) energy, where a number of mirrors reflect sunlight onto a tower where a liquid such as sea water is superheated, producing steam which can rotate a turbine and generate electricity as a result. Both of these technologies continue to develop, and are commercially viable in regions of the planet with consistently good sunlight such as Spain.

But the vast majority of people live in parts of the world that aren’t quite so sunny, yet there is still enough energy from the sun to make solar power a viable alternative to consider. All we have to do is harness the sun’s energy in simpler ways than the solar farms needed for solar panels or CST do.

One method that has been in the works for a number of years is something referred to as a polymer solar cell (PSC). Most of the photovoltaic solar cells are made from purified silicon crystals, similar to those used in computer silicon chips. These types of solar cells are rigid, complex and expensive to make. In contrast, the PSC is much less expensive to manufacture because it can use printed electronics, it’s lightweight, flexible, and possibly even disposable. They have been less efficient than conventional solar cells made from silicon crystals but have been heavily researched and developed because of the advantages listed above.

Last week, a research team from UCLA have come up with a version of PSCs that can be applied to windows. They generate electricity but people can still see through them. They’re about 70 percent transparent because most of the energy they absorb is from infrared radiation rather than visible light, one of the groundbreaking achievements over earlier prototypes making this news particularly exciting.

The leader of the PSC research at UCLA is Yang Yang, a professor of materials science and engineering, as well as director of the Nano Renewable Energy Center at California NanoSystems Institute (CNSI). He stated ”These results open the potential for visibly transparent polymer solar cells as add-on components of portable electronics, smart windows and building-integrated photovoltaics and in other applications.” Their work was published in ACS Nano.

Obviously an announcement as recent as this means there’s a way to go before commercially viable PSC windows will be part of mainstream building materials. But any concerns about the 30 percent loss of visibility associated with this type of window will only diminish as further research and development will lead to even further improvements.

But this type of development is just one of the many ways to think outside the box and look toward innovative ideas that generate electricity in ways other than fossil fuels. What a brilliant way to help buildings generate their own electricity and minimize their emissions.

I applaud Yang Yang and the research team and wish them continued success in their efforts.