Presenting to 3rd graders in Paradise, California as part of Paradise Intermediate School’s “Solar-bration,” fifteen-year-old Mario Visinoni showed the students how to measure energy use for all sorts of household gadgets with the help of a kilowatt meter. Mario then conducted a contest among the third graders: Each student had to guess how much wattage an appliance used. Those that guessed within 50 watts got a prize.

Focusing on phantom loads, Mario explained in the online journal “Energy Seeds” how almost every home appliance uses some amount of energy, even when turned off. Leaving a power strip on, for example, even when the connected appliances are off, can suck serious energy over time. At his own school, Mario calculated over $4,000 in yearly phantom-load costs. Mario’s work has had a great impact on his community and, as his sixth-grade science teacher Greg Holman put it, “Mario’s enthusiasm and youth capture a greater audience than ‘just another teacher talking to us.'”