Spray-on Solar Panels

According to the National Renewable Energy Laboratory (NREL), by 2020 photovoltaic (PV) technology will represent 15 percent of the energy consumed in the U.S. and the National Center for Photovoltaic (NCPV) expects that 10 percent of the power produced during peak times will be by solar energy. Solar energy is plentiful, clean, and renewable. In fact the amount of energy provided by the sun in one hour theoretically is enough to meet the entire planet’s energy requirements for one year. The challenge is how to harness it and put it to efficient use economically:

• Traditional solar panels are composed of crystalline silicon PV arrays and they are costly to manufacture. They use hydrogen plasma to collect the sunlight and are constructed in a vacuum.
• Recent advancements in technology have resulted in the development of thin-film solar cells, which are considerably more flexible that the rigid panels and are able to be used on windows, the sides of buildings, cars, etc. Though these cells use less expensive materials, their complexity makes them significantly more cost to produce, resulting in a more useful, yet more expensive product.

A potential solution lies in the initial stages of development, where researchers are developing ways to change the manufacturing process for solar panels and improve overall efficiency in operation. The term used to describe the end product is “spray–on solar panels.”

Spray–on Solar Panel Project

There is currently a project ongoing to increase the efficiency rate of solar cells by 500 percent. When initially manufactured in the 1950s, solar panels converted less than 4 percent of the collected solar energy into usable power. Solar panels now convert approximately 15 percent. The ongoing efforts could result in efficiencies in the range of 75 percent:

• Phase 1 is focused on simplifying the manufacturing process, thereby lowering the costs. As the solar panels roll down a conveyor belt during production they are sprayed with first, a hydrogen film and then an anti-reflective film. They are lighter and cleaner and are the first solar cells to be able to collect both visible light and infrared waves.
• Phase 2 will investigate ways to improve the efficiency of the cells, with initial attention being paid to their surfaces.

Possible Applications of Spray–on Solar Panels

With the exception of rigid solar panels on the rooftops of some homes, the traditional commercial PV solar energy systems are not available to the general public. Their applications typically involve the powering of spacecraft or bringing electricity into remote villages of developing countries. The more flexible thin-film PV technologies are more apt to be installed in private homes, in use with electronic devices, and also in situations involving remote locations. The spray–on solar panels, sold as a hydrogen film that can be applied as a coating to materials, can be used for anything from a small electronic device, an electric car’s battery, and on building themselves (not just rooftops).

Challenges and Opportunities

It should be pointed out that this capability does not exist outside of the laboratory. Testing is ongoing, but commercial application is not anticipated until 2012; and there are significant financial hurdles to overcome as a struggling economy can impact research and the adoption of new technologies:

• The market growth rate of the PV solar panel market was over 30 percent annually  over a 4-year period in the early 2000s but it has has declined sharply in recent years due primarily to the economy and high manufacturing costs.
• Industry experts are anticipating that these growth rates will return, as this spray–on production method will save a typical solar cell producing factor $4 million, savings that when passed on the consumer, will make solar energy technology more affordable.