The word “daunting” pretty well captures the scope of today’s energy challenge, says Ernest Moniz, head of the new MIT Energy Initiative (MITEI). That’s mainly because the world’s energy system faces rapidly growing demand.

“The UN estimates global population will rise by 3 billion within a half century,” says Moniz, professor of physics and engineering systems. “You also have these fast-growing economies, like China and India, meaning that much more demand.”

Today’s energy infrastructure would have had to be replaced over the next 50 years anyway. But high demand, says Moniz, means that “you’ve got to build a whole second infrastructure the size of the one you’re building to replace what’s there now — and do it without increasing the greenhouse gas emissions linked to climate change.”

MIT is gearing up in response. Among its initial steps: setting research priorities, and filling six new faculty slots.

Those positions will cover gaps in MIT’s expertise. But Robert Armstrong, MITEI’s associate director, notes that such gaps are few. “It’s striking where we are on energy,” says Armstrong, a professor of chemical engineering. “We have great breadth.”

On the education front, MIT is creating new options in energy, including two freshmen offerings. Armstrong notes that there’s lots of student interest: at a grad student’s recent defense of his thesis on the economics of ethanol, “the room was packed with students wanting to know what the economics were, did it pay to use corn, and were there better alternatives.”

Here are visits with a few of the MIT people who’re changing the shape of the energy landscape.

For related energy stories, please see MIT’s video magazine ZigZag:

ZigZag: All-energy episode Episode 11