Teenager’s Invention Saves Fuel for School Buses

A new attachment can improve school bus fuel economy by as much as 20 percent

Fuel economy is hardly the most popular subject among teenagers, but it’s a passion for 17-year-old Jonny Cohen, who’s found a way to save schools money and reduce greenhouse gas emissions by increasing school bus fuel efficiency.

The idea popped into his head on a walk home from school when he was 12. The then-seventh-grader was taking summer classes on aerodynamics at Northwestern University, and it dawned on him there must be a way to streamline the bulky, boxy shape of school buses.

“I like to see things that are efficient. Things that are inefficient use more energy and are polluting,” said Jonny, who lives in Highland Park, Ill. “I also understood that reducing carbon emissions from a school bus could reduce global warming.”

With the help of friends and his sister Azza Cohen, a more formal effort took shape in 2008. They called it the Greenshields Project.

Azza, 19, said Jonny has always been an inventor. He blew things up, made his own intercom system and crafted a device to put cheese on a hamburger. But when Jonny ran into her room saying he could revolutionize school buses, Azza didn’t think much of it at first.

“He’d had a lot of crazy ideas before, and I’d never really believed them,” she said. “You’re less inclined to believe a 12-year-old when they say they have a solution to a really pressing problem.”

School bus emissions are a pressing issue. According to U.S. EPA, diesel exhaust from school buses contains pollutants that contribute to ozone formation, acid rain and global climate change. In addition, the fine particulate matter from diesel engines can cause lung damage, especially in children, and contributes to haze.

EPA created a national idling reduction campaign to cut down on air pollution from buses. But, to date, no product or program exists that would reduce emissions quite like the GreenShield.

Putting a fuel hog on a diet

Jonny’s original idea was to attach a streamlined, transparent Plexiglas cover over a school bus windshield to reduce drag and allow the vehicle to use less fuel.

The fourth-generation GreenShield, produced with help from Northwestern University’s Segal Design Institute, looks radically different. Instead of a shield, it’s more like a ski-jump-shaped hat installed on the roof of a bus, which reduces material and installation costs. Research shows the efficiency benefits are about the same.

Virtual, on-road and wind tunnel tests on school buses donated by the bus company Cook-Illinois Corp. found the GreenShield improves fuel economy 10 to 20 percent.