He's responsible for ecological feat

Dr. Jayant Baliga is a man of average size, but he probably has the world's smallest footprint. Carbon footprint, that is.

Baliga, a professor of electrical and computer engineering at N.C. State, is the inventor of a power-saving switch that prevents 1.4 trillion pounds of carbon dioxide from being released into the atmosphere each year, at a cost savings of $300 billion.

And by saving 125 gigawatts of power each year, Baliga has offset the carbon footprint of 175 million people. You'd have to plant tens of millions of trees to achieve the same effect.

Now he may make big changes in the nation's electrical grid. He's a finalist for a National Science Foundation grant that would support research into how to deliver energy more efficiently.

Meanwhile, consumers already use Baliga's technology every time they turn on a television, power up a computer or switch on the air conditioning.

Baliga's chief invention, called an insulated gate bipolar transistor, is an improvement to the original transistors developed at Bell Laboratories in the 1940s.

As the building blocks of all modern electronics, transistors are arguably the most important invention of the 20th century. The devices amplify and switch electrical signals, and their low cost and ease of production means that millions of them can be lined up on a single microchip. But before Baliga, they were very energy inefficient.

Baliga likens the concept to a hose: “If you think of a garden hose, you have water running through the spigot and into the hose at full speed. But if you want to control that flow, you must use a damper somewhere inside the hose to decrease the water coming out. A lot of energy is lost at the damper.”

But if you could decrease the flow of the water at the spigot you'd save a tremendous amount of power, Baliga says.

And that's precisely what the IGBT does. Baliga made the breakthrough while working at General Electric.