Transparent Solar Panels

published Sep 03, 2014
2 min read


What Are Solar Panels?

Solar panels are represented by either photovoltaic (PV) modules or  solar thermal panels. PV panels are used to generate electricity in residential and commercial buildings. Each module is rated by its DC output power under standard test conditions (STC), which typically ranges from 100 to 320 watts. A module’s efficiency refers to the amount of sunlight the panel is able to convert into actual electricity. The resulting output of the PV system will be determined by the efficiency of the panels, the size of the system and the amount of sunlight it receives.  There are few basic solar panels that exceed 19% efficiency. The typical PV system includes a set of panels, an inverter, and a solar tracker with interconnecting wiring. If the system is not connected to the grid, then it often includes a battery as well.

Technology Development


The new technology that is close to emerging into the market has the potential of being deployed in order to create self-sufficient buildings and even mobile phones that won’t require charging. The researchers from the Michigan State University that developed it call it the “transparent luminescent solar concentrator”, which can be used on mobiles, buildings, basically every device that has a clear surface. Traditional solar panels get energy from the sunlight through dark silicon cells. Afterwards, the energy is converted to electricity. In the case of this new system, the plastic-like material conveys certain wavelengths of sunlight towards the photovoltaic solar cells placed on the edge of the panel. Given the fact that the materials do not absorb or emanate light in the visible spectrum, they look transparent to the naked eye.

Up to this moment, the conversion efficiency is not the best. Michigan’s team design has just 1% efficiency, but is aiming for 5% in the future. Their closest competitor has a conversion efficiency of 7%, with opaque solar cells reach 12% efficiency. The team from Michigan thinks that this technology could open new opportunities for households and businesses, making their pursuit worthwhile. This is believed due to the fact that the film could be applied on every clear surface, thus turning your tablet or smartphone into a solar powered device. At first, the applications for these efficient transparent solar concentrators can be expensive. They could be installed on skyscrapers with lots of windows, or integrated on car windows to energise electric cars. Their ultimate aim is to make solar take-in surfaces easily reachable, even on areas that didn’t seem accessible up until this point.

The Michigan team isn’t the only one predicting such a future. Heliatek, a german solar company, issued a solar cell with a 40% transparency, earlier this year, and a 7% efficiency, using oligomers engineered in their lab, which also selectively absorb light. Also, engineers from Singapore’s Nanyang Technological University has disclosed a new type of solar cell material, which may be able to function as a touchscreen as well.

SolarWindow Technology


SolarWindow produces clean electricity on see-through glass windows, by using the energy of natural sunlight and artificial sources like fluorescent and LED lighting typically installed in offices, commercial buildings, and schools. This technology is under an exclusive worldwide licensing agreement with the University of South Florida, jointly with a Cooperative Research and Development Agreement with the U.S. Department of Energy – National Renewable Energy Laboratory sector, involving 42 patent applications. They already have several product development goals regarding SolarWindow technology:

  • SolarWindow – CommercialFlat glass product for installation in commercial towers under construction and replacement windows.
  • SolarWindow – Structural Glass – Structural glass walls and curtains for tall structures.
  • SolarWindow – Residential – Window glass for installation l in residential homes under construction and replacement windows.
  • SolarWindow – Flex – Flexible films which may be applied directly onto glass, similar to window tint films, in order to modify the existing buildings, residential houses and commercial buildings.
  • SolarWindow – BIPV – Building components combined with building-integrated-photovoltaic tools in homes, office towers and buildings.
  • SolarWindow – Coatings – For military and commercial aircrafts, adding extra security and safety for pilots.


SolarWindow – Coatings

  • They use the smallest functional organic solar cells, which are less than one quarter of a grain of rice. The cells have shown to be successful at producing electricity in a published peer-reviewed study in the Journal of Renewable and Sustainable Energy of the American Institute of Physics.
  • It can be sprayed on to see-through glass using a novel, patent-pending process.
  • Doesn’t require expensive high-vacuum or high-temperature production methods, thus it can be sprayed on to glass at room temperature.
  • It generates electricity from both natural and artificial light sources, exceeds nowadays commercial solar and thin-film technologies as much as ten-fold.
  • The layer measures less than 1/10th the thickness of thin film solar panels, to put it into perspective it represents only 1/1000th the thickness of human hair.

SolarWindow is capable of producing electricity on see-through windows and is under improvement in order to use it in the estimated 5 million commercial buildings in the USA and more than 80 million single detached households.

Read More: Implications of “Free” Solar Panels.