If someday, centuries from now, cities run on a never-ending supply of clean energy and deploy cutting-edge defenses against natural disasters, their citizens might thank the middle-schoolers who gathered Jan. 12 at the Eastland-Fairfield Career & Technical Schools in Groveport.

The contestants in the Future City Competition for the Ohio region were full of ideas to power and protect the metropolises of tomorrow. Teams from 15 middle schools spent months researching technologies and designing cities, then they presented their plans, models and 1,500-word essays to a panel of judges Jan. 12.

In "Meira Heima," an Icelandic city at the base of an active volcano in the 27th century, student engineers from Heritage Middle School in Westerville would use geothermal energy to power not only most of the city's everyday needs, but also a magnetic shield that could repel volcanic ash.

"It's like the shields on 'Star Trek' or 'Star Wars'," said Kaedance Cicchino, 14, an eighth-grader at Heritage. "It uses plasma with strong magnets."

That's not all. Meira Heima, "Greater Home" in Icelandic, also is connected to the rest of the world by a high-speed network of vacuum tubes, and the whole city, much like ocean-going cruise ships of today, uses giant gyroscopes to stabilize it against earthquakes.

It was a winning combination: The Heritage team took the top prize in the competition and now is eligible to compete in the national finals in Washington, D.C., in February against teams from other states.

Students at Dublin Sells Middle School chose a more tropical location for their city, "Spannande Leende," built on an island to withstand Caribbean hurricanes and to run entirely on wave, wind and solar power. The name is Swedish for "Exciting Smile," said Emily Carr, 12, a sixth-grader at Sells.

Sweden has pledged to have zero net emissions by 2045, and "We want to be like Sweden," Emily said.

The city has aerodynamic, reinforced buildings and wind turbines that can be raised into the sky to generate power or retracted during storms. Composting and recycling take care of 88 percent of the city's waste stream, said Anna Breen, 12, also a sixth-grader on the Sells team.

That number, 88 percent, didn't happen by accident, said team mentor Mindy Carr, a civil and environmental engineer and Emily's mother. In a grade school Girl Scouts project, some of the team members helped set up composting for Dublin's Bailey Elementary School cafeteria. They saw a 66 percent reduction in waste and then found that with additional recycling, they could divert 88 percent of the waste from the landfill.

"They've actually seen it," Mindy Carr said.

The team from Upper Arlington's Jones Middle School designed for a post-apocalypse world in which global temperatures have skyrocketed. In their city, "Cupola de la Vida," life goes on under a dome of ethylene tetrafluoroethylene "pillows" that shades residents from the hot sun while transparent photo-voltaic cells on the outside of the dome provide power.

The city's name means "Dome of Life" in Spanish, said Annie Hu, 14, an eighth-grader on the Jones team. A central tower, "like a tree trunk," supports the dome in a design that is meant to mimic the way a tree grows. Inside the dome, people can soar in pedal-powered ornithopters that use a Leonardo da Vinci design to fly like birds but are built with the latest lightweight materials.