Creating a New Way to Store Solar Energy

Jun 19, 2018

The solar energy industry is getting better and better at producing power at lower cost than ever before but storing that energy for a rainy day remains a major roadblock. Batteries have their limitations, but scientists at Virginia Tech are taking a cue from how nature’s plants store energy.    

Credit technicacuriosa.com

Plants are actually nature’s storage systems for solar energy. They convert it into oxygen on a huge scale. Virginia Tech Chemistry Professor Amanda Morris and her team are working on a way to mimic how plants make that transformation, but instead of oxygen, they want to make methane.

“Methane is a chemical fuel that we use now,” notes Morris.  “We can combust it in our boilers at home to heat our houses.  There are buses that are powered on methane gas, so you can imagine that we can use that as a direct energy source.”

But, conventionally burning methane sends carbon dioxide into the air.  So they’re working on capturing the CO-2 and converting it back to methane, to create an infinitely renewable cycle.

Plants come equipped with that transformation system that begins with oxidizing water, the first step in photosynthesis, but Morris is creating a new kind of molecular scaffold to do it.

“The way that I like to describe it is ‘molecular swiss cheese,’" says Morris. "You can picture a block of cheese with all these holes going through it. Replace the cheese with small chemicals and that’s what we’re working with.”

The goal is to achieve ‘artificial photosynthesis.’ And like the process of photosynthesis in plants, the gases in these methane power plants would be constantly recycled.

“So, we create a recyclable fuel stream. I think that would be a game changer.” But, she adds, “we also could change the way we make every day materials. I mean the plastic that’s on your phone; we could actually think about, how we make precursors to the polymers that are in these plastics. There’s a lot of places where this chemistry could potentially impact our daily lives.”

Morris says several companies are interested in this kind of CO-2 transformation. But her research will take more time.

She gives a shout out to the U.S. Department of Energy. She says she doesn’t mean to be political, but she hopes people will support the DOE for funding this kind of pure research because, this is what it takes to make these kinds of discoveries.

“We can’t necessarily say that our technology is going to be on the market in 10 years,” she says, "but we couldn’t say that about lithium batteries (at one point, either)  and now they’re ubiquitous. And it’s really this fundamental research that the Department of Energy supports at universities that pushes our lives further.”

Morris presented her latest findings to DOE a few weeks ago and was told the results are impressive and that this is the first time a Nano molecular structure has shown promise for supporting artificial photosynthesis.

And that means there’s a chance it just might prove to be part of the missing link between creating solar energy and storing it in large quantities.