The United States recently passed an important landmark. In March, 10 percent of the nation's power came from renewable energy. Over the next few years, that number will only increase, but renewable energy has a big weakness: It's tough to power our homes using a source that can wax and wane with barely any notice.
This is a challenge for most forms of renewable energy, but most of our renewable energy comes from wind, which is among the most unpredictable. The behavior of wind near the ground, where turbines spin, is highly variable. But a few miles up winds are strong and steady, ideal for power generation. All we have to do is tap into them.
Conventional wind turbines can't reach the necessary altitudes. There are some plans to lift a wind turbine to that height using balloons, but perhaps the best approach is to use a kite. Or a pair of kites, to be precise.
Kite Power Systems is a U.K. company developing a new way to draw power from the wind using specially-designed kites that fly in pairs hundreds of feet above the ground, taking turns extending and retracting. Their motion powers a generator on the ground, which can produce kilowatts to megawatts of power, depending on the size of the kites, as Real Engineering explains.
This setup has a number of advantages over traditional turbines. The kites are cheaper and easier to build and set up, all of the moving parts are at ground level for easier maintenance, and the system is much more durable and will last longer. The only part that's likely to break is the tether, which is a simple steel cable that's easy to replace.
This type of power generation could be the key to more widespread adoption of wind power. Depending on location, kite-based generators could provide stable, constant power almost every day of the year, eliminating the biggest disadvantage of renewable energy. Perhaps in a few years we'll all have kites flying overhead, powering our homes and lives.