We hear a lot about how technological advances and breakthroughs are needed to advance clean energy, we hear a lot less about the headway scientists and researchers are actually making.

Take this idea: a three-layer liquid battery that stores megawatts of energy from intermittent power sources like wind and solar. It can be the size of a truck or a house, says David Bradwell, an MIT doctoral student who's working on the project.

If successful, the project could eventually allow wind, solar, and other intermittent power sources to provide more than 20 percent of our energy needs.

Another MIT doctoral student, Johanna Engel, is part of a team that's working on an electrochemical cell that would use sunlight to split water into oxygen and hydrogen.

"The sun offers so much energy to the earth every day," Engel says.

That's PAETEC founder and CEO Arunas Chesonis's basic reason for funding these and other projects. Last year, the Chesonis Family Foundation announced it would provide MIT with $10 million over five years for a concentrated effort to advance solar technology. There are challenges to address - materials, efficiency, and cost, among them.

Between now and 2050, energy demands will increase exponentially, and those should be met by cleaner energy sources, Chesonis says.  But even a slew of hydroelectric, wind, and nuclear power projects won't close the gap.

"You still have a huge gap," he says. "You can't make a difference unless you look at something like solar."

A large-scale solar plant in the Nevada desert, for example, would generate enough electricity to power the entire country, he says.