The World's Smallest Carbon Footprint?

By Matt Shipman, News Services

Jayant Baliga is the director of NC State's Power Semiconductor Research Center.

NC State electrical and computer engineering professor Jayant Baliga, may have the world's smallest carbon footprint – the amount of greenhouse gases that a person directly or indirectly releases into the atmosphere each year.

One of Baliga's inventions is responsible for eliminating the need for more than 100 gigawatts of power, which translates to a reduction in carbon dioxide emissions of about 1 trillion pounds per year. Now, he is working to make his footprint even smaller by pursuing new inventions that further improve energy efficiency.

In 1980, Baliga launched a revolution in efficient energy use when he invented the insulated-gate bipolar transistor (IGBT) – a semiconductor that controls the flow of power from the energy source to whatever device needs the energy. The IGBT improves energy efficiency by more than 40 percent in an array of products, from cars and refrigerators to light bulbs and cardiac defibrillators.

The energy saved by the use of IGBTs in electric motors and energy-efficient light bulbs alone equals 100 gigawatts, meaning that new one-gigawatt, coal-fired power plants won't need to be built to match the former demand. There are economic benefits as well – to the tune of $2 billion for each plant that does not have to be built.

The United Kingdom group Carbon Footprint estimates that the average American has a footprint of 44,000 pounds of carbon dioxide per year, At that rate, Baliga's negative carbon footprint offsets the impact of more than 22.5 million other Americans every year.

Now Baliga, the director of the university's Power Semiconductor Research Center, is watching as another of his inventions, a semiconductor made of silicon carbide that is significantly more efficient than the IGBT, is beginning to gain widespread acceptance in consumer products.

The concept came to Baliga in the early 1980s, but limitations in the state of materials science at the time prevented him from pursuing that line of experimentation. As a result, Baliga joined the faculty of NC State in 1988 so that he could test his theory alongside some of the finest materials engineers in the country.

The move paid dividends – in 1991, Baliga was able to prove that his concept could work, significantly boosting worldwide research funding in the area.

"The worldwide acknowledgement of the importance of the idea was apparent from the initiation of major research programs in the U.S., Europe and Japan in the 1990s," Baliga said. "I am very pleased to see that many companies have launched products within the last five years making the technology available to consumers."

And Baliga is also finding commercial success with a silicon semiconductor he invented in 2004 to make power supply to computer microprocessors more efficient. This invention has already been adopted by many computer manufacturers and is being marketed for widespread application by a number of computer companies, including Dell and others.

Who knows how much further his carbon footprint will shrink?