Ecotech Energy Blog

Solar energy advancements

As solar cells are priced per watt, the efficiencies thereof are of utmost importance.  

The efficiency of solar cells has improved dramatically over time, with the advancement of technology.  In 1954, Bell Labs developed the first silicon solar panel with an efficiency of only 6 percent.  Solar panel efficiencies improved to around 14 percent by the 1970’s, while today solar panel efficiency levels are between 14 and 23 percent, depending on the model.  

As a result of technology advancements in solar cell design, the industry is seeing reduced costs and an increase in the competitive market among solar panel manufacturers.  Technology development improves solar cell efficiencies, reliability and lowers prices.  Due to a number of advances, the future of solar energy will likely change, making it more affordable to everyone.  

Three recent advancements include: 

Solar reflectance 

A drawback with solar cells is that they reflect a percentage of sunlight that falls on them.  The surface of the cell and the smoothed silicon structures inside the cell cause the reflectance.  The issue is that the reflected light is not usable by the cell.  Japanese based researchers have developed an anti-reflective coating producing sub-micron sized silicon pyramid structures that reduces surface reflectance to a mere 3 percent.  Furthermore, light-trapping microstructures were created to trap infrared light within the cell, booting solar cell energy efficiencies of up to 19.8 percent.  

Transfer Printing 

Further electronic technical advancements include the ability to print materials in ultra-thin layers that are thickness controlled, referred to as transfer printing.  South Korean researchers have discovered ways of applying transfer printing to perovskite (calcium titanium oxide) solar cells.  Converting sunlight to electricity is done highly efficiently by perovskite, making it an appealing material for solar cell construction.  Even though the material can be sprayed onto the solar cells, creating thin flexible cells, perovskites are high in defects.  Utilising transfer printing methods that control the ultra-thin layers, researchers have produced solar cells boasting efficiencies around 22.1 percent.

Internal Cube Design 

George Washington University researchers have developed gallium antimonide (GaSb) solar cells that are able to harvest energy from nearly all spectrums of light, including longer wavelength light energy, invisible in the solar spectrum.  The GaSb solar cell efficiency were dramatically increased due to the method used of changing the current flat design to a cubed version, harvesting the majority of the sun’s light energy.