A kite flown in a strong breeze will quickly unspool string as it climbs higher. KiteGen Research in Italy aims to turn that action into electricity. The company developed a prototype that flies 200-square-foot kites to altitudes of 2,600 feet, where wind streams are four times as strong as they are near ground-based wind turbines.

As the kite’s tether unspools, it spins an alternator that generates up to 40 kilowatts. Once the kite reaches its peak altitude, it collapses, and motors quickly reel it back in to restart the cycle. This spring, KiteGen started building a machine to fly a 1,500-square-foot kite, which it plans to finish by 2011, that could generate up to three megawatts—enough to power 9,000 homes.

Any blossom would stand out in the desert of southern Israel, but you’d be hard-pressed to miss a 98-foot-tall one. The tulip-shaped tower is the centerpiece of the world’s first hybrid-solar power plant, opened this summer by Israeli start-up AORA Solar. An array of 30 mirrors focuses the sun’s rays on the central steel bud. Inside, the solar energy heats air to 1,800ºF, causing it to expand and spin a turbine to generate 100 kilowatts. When night falls or clouds obscure the sun, the plant helps heat the air with a standard diesel combuster running on up to eight gallons per hour to provide consistent electricity output, unlike strictly solar plants. AORA is working with Spanish, Chilean and Australian companies to export the tech, which could be reconfigured to burn biofuel, says Pinchas Doron, the company’s chief technology officer. “Soon,” he says, “it could be green energy 24/7.”