Scientists Created The Most Efficient Solar Cells Ever

Scientists Created The Most Efficient Solar Cells Ever
Dr Mark Keevers with one of the spectrum splitting, four-junction mini-modules developed at UNSW.

The conversion of sunlight to electricity has been studied in depth for many years. Engineers in Australia, however, have brought into their research many convincing theoretical limits. Once such introduction is the construction of photovoltaic cells. These are believed to have the ability to harvest 34.5 percent of energy from the Sun. This is an extreme amount of power that can be used. This accomplishment has taken place without the use of concentrators. The event has caused a new world record to be set.

An earlier world record topped out at 28,8 percent of the Sun’s energy. This record was set by the United States built a solar cell that reached the size of 800-square centimeters. While this was an amazing accomplishment, the photovoltaic cells are smaller and act more efficiently. This will contribute to the cost-effectiveness of solar energy.

To save money on solar power, Mark Keevers of the University of New South Wales, states that “Extracting more energy from every beam of sunlight is critical to reducing the cost of electricity generated by solar cells as it lowers the investment needed, and delivering payback faster.”

There were other studies, one by this same UNSW team in 2014. This record was set with the use of mirrors. The mirrors were used to concentrate sunlight. The experiment yielded 40 percent efficiency rates. However, the new method is more efficient, as it does not require any type of concentration. The task was accomplished far earlier than ever expected by professional engineers.

Scientists Created The Most Efficient Solar Cells Ever
Each layer of the four-junction cell extracts energy at its most efficient wavelength, while unused light passes through to the next layer. 

The cell in question is sized at a mere 28 centimeters (11 square inches). The sunlight that comes in is broken up into four brands with this method. The band that identifies as infrared is purposely directed back to a silicon solar cell. The remaining three bands are sent to a three-layer solar cell that is new in construction. It consists of indium-gallium-phosphide, germanium, and indium-gallium-arsenide.

Each of these layers receives the sunlight and extracts as much energy as possible. The light that fails to be used passes through to the next layer. This raises the efficiency level by making the effort to harvest as much as possible in each layer.

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While this is great news for the future of energy use. These cells are not to be expected to appear in homes anytime soon. The maintenance and cost are fares more than the common single-junction solar cells. Work will have to be done to make them more cost efficient and more widely accessible by the population.

These new cells, however, are perfect for solar towers. Towers use mirrors to increase the concentration to a series of cells. This is then converted into electricity. Heat is often used to accomplish this task. Well-known plants that actively use this system are located in Morocco, Sweden, and Australia.

The next step taking place is to raise the size up to 800 square centimeters and research the energy results. This could mean significant changes for energy availability. The theory, at present, revolves around a 53 percent expectation for the four-junction system.  The team at UNSW considers this only 2/3 of the way to the ultimate goal. When the size is expanded there is expected to be a marginal loss from the interconnection.

This new technology will bring costs down in the future for solar power. The goal is to put it to use in large solar plants. Peer reviews are now underway. The US National Renewable Energy Laboratory has already confirmed the 34.5 percent efficiency record.