You know that little Energy Star logo that you see on light bulbs and appliances? You can thank one man for saving you thousands in energy costs.

Dr. Arthur Rosenfeld is the father of energy efficiency.

The 80-year-old particle physicist is renowned worldwide for his pioneering work in making energy more efficient.

His lab is responsible for hundreds of innovations that have decreased the amount of energy waste in the world, including energy-efficient windows and light bulbs.

Dr. Rosenfeld’s work is credited with saving the U.S. nearly $1 trillion.

He talked to Growing Bolder about what it’s like to be the world’s first “eco-geek,” and what it meant to him to receive a prestigious award from President George W. Bush last year.