Photovoltaic capacity is growing rapidly in the US (and elsewhere). According to the Solar Energy Industries Association (SEIA), the solar energy market has grown 24% annually over the last decade alone. The US already has 149 gigawatts of installed solar capacity, which could theoretically power 26 million homes. The future also looks bright, with SEIA and Wood Mackenzie predicting the solar market to triple in five years to 378 gigawatts by 2028. In 2022, 1.2 trillion watts of electricity produced worldwide will be solar.
[Related: Floating solar panels could be the next big thing in clean energy.]
Developing and investing in solar energy is vital to building a cleaner and more sustainable future, as this technology enables the planet to produce large amounts of energy without emitting harmful greenhouse gases. Technology has come a long way in recent years (and has come on leaps and bounds since its inception in the 1800s), but the average efficiency of solar panels is still around 15-20%. This means that about 80-85% of the raw energy emitted by our favorite star is lost. Not to mention that silicon solar cells, the most widely used photovoltaic technology, have a theoretical efficiency limit of 29%.
Scientists have been trying to solve this problem for years. The NREL team has developed a panel with 47% efficiency, but unfortunately the model is a bit expensive for general use. However, two different groups of researchers, detailed in two separate papers published July 6 in the journal Science , have found the necessary growth for silicon solar cells: the perovskite.
According to the University of Washington, perovskite is a mineral that has the same crystal structure as calcium and titanium oxide, but can be made up of several different elements for different purposes. They also produce ultra-stable semiconductors for solar modules with lab-measured efficiencies of 25.2%.
The two teams combined perovskite with silicon to create a tandem solar cell. These technologies are not necessarily new; the first was developed in 2009, and a group in Hong Kong improved the efficiency to 25% in 2016. But now scientists are reaching an even higher level.
In one study, Xin Yu Chin of the Ecole Polytechnique Fédérale de Lausanne in Switzerland and his team used a perovskite top cell and a silicon bottom cell and added phosphonic acid additives during cell processing. Their cell achieved 31% efficiency.
Another team, led by Silvia Mariotti of the Helmholtz Center for Materials and Energy in Berlin, used an ionic liquid called piperazinium iodide to grow a tandem solar cell and achieved an efficiency of up to 32.5%.
"Breaking this threshold ensures that high-efficiency, low-cost PVs will be brought to market," said materials scientists Stefan de Wolff and Erkan Aydin, who were not involved in the study. study in a future journal article. science .
[Related: Scientists believe we could have 90% clean energy by 2035.]
Competition is heating up outside Europe as well. Professor de Wolff at Saudi Arabia's King Abdullah University of Science and Technology says his team achieved 33.7% efficiency in a tandem cell test earlier this year. The Chinese company LONGi, which produces the most solar cells in the world, announced last month that it has developed a tandem solar cell with an efficiency of 33.5.
As exciting as all of this is, this is just the beginning. We need more clean energy to reduce greenhouse gas emissions for the planet to survive.
"Breaking the 30 percent threshold ensures that highly efficient and cost-effective PV systems can be brought to market," De Wolff told the Guardian. "To avoid global warming catastrophe scenarios, total capacity must increase to around 75 TW by 2050."
