Shedding Light on Solar’s Future
This 15% is all we typically get out of a photo-voltaic solar cell when it comes to energy conversion. Something you may not realize is that Solar energy conversion is still in it’s infinite stages with new technology and development bridging the gap to gain the additional 85% of energy loss.
When the day comes that solar cells capture even 70% of their potential the cost factor to install solar-photo-voltaic systems in commercial, industrial, and most importantly, residential will be far better than other means of generating energy in the future.
How close are we to reaching 70% efficiency?
Amazingly, utilizing multi junction compound solar cells Sharp has achieved 44.4% conversion efficiency.
Sharp corporation has truly come a long way with this emerging technology, with the following their press release from 2013 on the achievement.
Sharp Corporation has achieved the world’s highest solar cell conversion efficiency*2 of 44.4%, using a concentrator triple-junction compound solar cell. These solar cells are used in a lens-based concentrator system that focuses sunlight on the cells to generate electricity.
This latest Sharp breakthrough came about through research and development efforts that are part of the “R&D on Innovative Solar Cells” project promoted by Japan’s New Energy and Industrial Technology Development Organization (NEDO).*3 Measurement of the value—which sets a record for the world’s highest concentrating conversion efficiency—was confirmed at the Fraunhofer Institute for Solar Energy Systems (ISE)*4 in Germany.
Compound solar cells typically offer high conversion efficiency while utilizing photo-absorption layers made from compounds of multiple elements, such as indium and gallium. Sharp’s concentrator triple-junction compound solar cells use a proprietary technology that enables the efficient conversion of sunlight into electricity by means of a stack of three photo-absorption layers, the bottom-most of which is made from InGaAs (indium gallium arsenide).
To achieve a concentrating conversion efficiency of 44.4%, Sharp worked to widen the effective concentrator cell surface and ensure uniformity of width at the interface of the connecting concentrator cell and electrodes.
Because of their high conversion efficiency, compound solar cells have thus far been used primarily on space satellites. Looking to the future, Sharp aims to harness this latest development success and make the use of compound solar cells more feasible in terrestrial applications.
Space Based Solar Power
Every hour, more solar energy reaches the Earth than humans use in a year. About 30% of this energy is reflected back into space by the atmosphere. In the figure below, Sunlight reflects off these large mirrors into the center of the satellite.
Scientists are resurrecting a technology that was first tested over forty years ago in which space-based satellites capture sunlight and convert it into microwave energy that is then beamed back to earth. This type of technology promises to capture significant more amount of sunlight (nearly ninety percent) since satellites can be positioned to optimize light capture round the clock. India, China and Japan are investing heavily in these technologies right now. The united states also looks to be a leader in this technology and with the new space force being commissioned by the Trump administration this technology could be a major investment in producing solar power in a very short amount of time.