Could the day we use our sweaters to charge our cell phones be approaching fast?

Researchers at the University of Toronto have invented a flexible plastic solar cell that promises to be more efficient than any other solar cell on the market at converting energy from the sun into usable electrical energy. They hope to one day be able to weave this into clothing to charge cell phones and other electrical instruments.

According to a press release on the University of Toronto’s Web site, at its very best, the new technology has a 30 percent conversion efficiency rate — which is five times better than the average of 6 percent that current solar energy cells possess.

Mike Coon, chief operating officer of Iowa Thin Film Technologies Inc. in Boone, said the business makes flexible, lightweight plastic base material and then deposits solar cells onto it.

Coon said thin films, unlike the films developed by the University of Toronto, are in the range of 5 percent conversion efficiency rate. Some can go as high as 8 to 10 percent, but they are much more costly.

“Because it’s new technology, I think it’s exciting,” said James Hill, university professor of chemical engineering. “It can lead to things we haven’t even conceived of.”

Hill, who is also an adviser to Team PrISUm, the ISU solar car team, said people could spray their roofs with these new solar cells, allowing all electrical appliances in the house to run off the solar energy.

But, he said, the technology is still in the research stage.

Justin Steinlage, project director of Team PrISUm, was more skeptical about the new solar cells.

“There’s a chance this new technology will never see the marketplace,” said Steinlage, senior in mechanical engineering.

He said there were other options, such as silicon cells, that are decreasing in price.

Steinlage said, although the new technology promises 30 percent conversion efficiency, this is only the case when it’s at its absolute best.

Thin films will eventually hit a conversion rate limit.

“I don’t think thin films will ever surpass 30 percent,” he said.