Solar panel efficiency is described as the conversion of incoming sunlight to electricity. For 15 years, the solar panel efficiency was stuck at 23%. However, with the latest advancement, the efficiency of the solar panel has increased to 29%.
The latest experiment conducted by the researchers at UC Berkeley increased the efficiency of solar cells by combining photovoltaic and thermovoltaic processes.
There is a difference between the photovoltaic process and the thermovoltaic method of producing electrical energy. In the photovoltaic process, the energy supply chain begins from the sun to earth and then to the solar panel, thus producing energy.
In the thermovoltaic process, the energy source can be any hot object, including the sun– which sends infrared radiation to thermophotovoltaic cells which then produces electricity.
Scientists at UC Berkeley have combined these two processes to increase the total efficiency of solar panels all the way from 23% to 29%.
Solar Panel Efficiency Breaks Record
In 2019 the latest efficiency record achieved by a solar panel stands at 29%. All this was made possible by Zunaid Omar, Luis M. Pazos Outόn and Eli Yablonovitch, who authored a paper titled “Ultraefficient thermophotovoltaic power conversion by band-edge spectral filtering” published in the Proceedings of National Academy of Sciences.
The solar panel achieved this efficiency by adding a layer of a highly reflective mirror behind the photovoltaic cell. This mirror creates a dense photon gas within the solar cell which increases voltage.
The mirror also reflects back thermal photons which have very little energy. Thus giving them another chance to get absorbed by the solar cell to create electricity.
The team used a gold mirror to increase efficiency to 29%. According to the researchers, the efficiency can also be increased to 36% by adding a dielectric layer above the gold surface.
Solar Panel Efficiency Can Make Deep Space Travel Possible
The team is confident that efficiency can be increased to 50% using some additional beneficiary techniques already known to scientists.
Once the solar panel achieves 50% efficiency, its applications are almost limitless. These solar panels can be especially useful in deep space travel. Probes that go far into space can be powered using these photovoltaic cells for centuries.
According to the researchers, the thermovoltaics used to boost the efficiency of solar cells are very compact in nature. They can power 100-watt electronic devices and 100-megawatt unmanned aerial vehicles alike.
For flying drones, this means that they can fly for days in the sun without any recharge.
An entire house can be powered by a generator the size of an envelope, says the authors.
Solar Energy on the Rise
In the past few years, the sale of solar panels has really gained speed. Nations from around the world are pouring billions into renewable energy. For example, India’s renewable energy recently became the cheapest in the entire Asia Pacific region.
This will prompt more competition in the market, thus triggering even more scientific research in making solar panels more efficient.