Sunlight is already providing a growing amount of our electricity. Now researchers at the University of North Carolina think they can utilize the rays to turn air pollution into cleaner fuel.
If successful, the tech would provide a way to essentially store intermittent solar power as methanol, which could be later used to provide energy — as discussed in a recent paper.
"One challenge with solar energy is that it's not always available when we have the highest need for it," Gabriella Bein, the paper's first author, said in a lab summary. "Our goal is to store solar power in the form of liquid fuels that can be used later."
The experts' work is inspired by how plants can naturally convert planet-warming carbon dioxide into "energy-rich molecules" using sunlight through photosynthesis.
The innovation is coming out of the Center for Hybrid Approaches in Solar Energy to Liquid Fuels (CHASE), based at UNC. The science leverages $40 million in government funding, all per a report from the university.
It works by using a severe-sounding technique called methyl termination. The scientists used a compound of "one carbon atom bonded to three hydrogen atoms to modify the surface of silicon." Silicon is a crucial part of solar cell technology. When added to the silicon, the compound improved the material's ability to turn carbon dioxide into carbon monoxide using the sun, as the experts explain it. They added that it's a "less-harmful" planet-warming gas.
More importantly, it can be used to make fuels like methanol. The University of Southern California reports that methanol is cleaner burning than gas, but it doesn't provide the same range when powering a car.
The UNC process was able to make carbon monoxide with an 87% efficiency rate. The process eliminated production of other unwanted byproducts. It's a cleaner process, as sunlight is used to drive the chemical reactions, not electricity.
It "could be really useful for making liquid fuels from sunlight in the future," CHASE deputy director and paper co-author Jillian Dempsey said.
The UNC team aptly describes the practical potential in their report: "Picture the gasoline in your car. When gasoline combusts, it produces carbon dioxide, water vapor, and energy. What [the researchers are] trying to do, in essence, is to reverse that reaction and use carbon dioxide, water, and energy to produce fuel" — all powered by sunlight.
Another project tackling artificial photosynthesis is being developed in Cambridge. Those researchers are creating fresh water and hydrogen fuel with help from the sun.
While these innovations won't immediately make a large-scale impact, there are ways to maximize the sun's power now. Home-based solar technology is becoming easier to obtain and install, as well as less expensive, especially when considering tax breaks. While a setup could cost upward of $16,000, about $4,600 in tax benefits and annual energy savings of $1,500 can lead to long-term gains.
That's not mentioning the better health everyone enjoys (see ya later, asthma) by reducing fossil-burning air pollution.
The effort from the Tar Heels to use sunlight in novel ways for energy production is an exciting twist for the abundant, natural power source. The team is four years into its work. The hope is that the research is funded for another five to bring it to technological "readiness."
"There's obviously a major need to move away from fossil fuel energy sources toward sustainable energy sources to meet our growing energy needs and mitigate climate change," Dempsey said in a UNC press release.
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