ScienceWorld: WILDLIFE CRISIS April 13th, 2015 Article: Wind Catcher Sky-high turbines could capture strong winds that blow far overhead BY JENNIFER BARONE | FOR Giant balloons will soon dot the skies above Fairbanks, Alaska. But these aren’t hot-air balloons. They’re floating turbines—a new wind-powered source of electricity. Engineers at the company Altaeros Energies in Massachusetts created the technology. They hope the design will bring additional sources of power to remote regions, as well as solve challenges posed by conventional wind turbines. POWER SUPPLY Most power plants produce electricity by burning fossil fuels, such as coal, oil, and natural gas. But burning them can cause air pollution and contribute to climate change. The supply of fossil fuels is also limited. They’re mined from the ground, and eventually, they’ll run out. Wind, on the other hand, is a renewable resource. It doesn’t get used up. That makes it an appealing source of power. Wind turbines are used to convert wind energy into electricity. Most turbines look like giant fans sitting on top of towers up to 140 meters (460 feet) high. As wind pushes the blades, the turning motion powers a generator that makes electricity. UP, UP, and AWAY Conventional wind turbines work great on windy days. But if it’s calm, their blades don’t spin, and they can’t produce energy. Turbines that reach higher into the sky would be able to produce energy more reliably. “As you go higher up, the winds get stronger and steadier,” says atmospheric scientist Ken Caldeira of Stanford University, in California. That’s where the floating turbines soon to appear in Fairbanks come in. The buoyant airborne turbines, or BATs, as they’re called, resemble what you’d get if you were to cross a conventional wind turbine with a blimp. Each one consists of a floating helium-filled shell with a turbine inside. Since helium gas is lighter than air, cables must anchor the system to the ground so it doesn’t float away. The turbines in Alaska will hover about 300 m (1,000 ft) in the air. That’s more than twice the height of the tallest conventional turbines. “Going a little higher opens up renewable energy that’s available cheaply almost anywhere,” says Christina Archer, an engineer who studies wind power at the University of Delaware. AIRBORNE ENERGY Although the floating turbines are too small to provide enough electricity for big cities, Altaeros says their design represents a good solution for remote communities and disaster relief efforts. Typical turbines can take months to set up. They require cranes and cement foundations for installation. But a BAT can be packed into a shipping container and trucked wherever it’s needed. Once it’s on-site, it takes just a day to inflate it and hook it up to a ground station. The power it provides can then flow to the electrical grid or other equipment. In 2013, Altaeros successfully tested a BAT flying at 150 m (500 ft) in Maine. “It’s amazing to see something that can be packed so small inflate to get so large, go up overhead, and produce electricity without any tower,” says Ryan Holy, a manager at Altaeros. LOOKING AHEAD If the BATs in Alaska reach 300 m (1,000 ft) as expected, they’ll set a record for the highestflying wind turbines in the world. But Altaeros has competition. Other companies—like Makani (owned by Google), Ampyx in the Netherlands, and KiteGen in Italy—have developed their own designs to harness winds that blow far overhead. With the right technology, high winds could become a significant power source for the world. “The energy available is several times greater than what humanity could ever possibly need,” says Archer.