Lighting makes up nearly 10% of the energy costs in our homes. But how many of us actually flip off the light switch when leaving the room? Over the past 16 years, Tien Nguyen, a veteran analyst in the Fuel Cell Technologies Office who just retired, did just that every night before he headed home from work—saving roughly $200,000 and enough electricity to power 150 homes for one year in the process.

Read the Energy Department’s recent blog post, Energy Department Veteran Saves Electricity One Light Switch at a Time, to learn more about how one person can make a big difference when it comes to saving energy.