AORA's Tulip solar power system is more than hot air
By Ben Coxworth
April 4, 2012
A giant flower has recently sprung up near the southern Spanish city of Almeria. Measuring 35 meters (115 feet) high, the Tulip is the product of Israeli company AORA, and it uses heat from the sun to generate electricity. Work began on the hybrid concentrating solar power technology back in the 80s and the first Tulip pilot plant was installed at Israel’s Kibbutz Samar in 2009. That setup has been pumping electricity into the country’s power grid every year since. The Spanish plant was completed this January.
The scalable, modular system incorporates 52 mirrors – or heliostats – which are arranged on the ground around the base of the Tulip. They turn to track with the sun, reflecting and concentrating its rays onto the plant’s top-mounted “bulb” at all times of the day. This causes the air inside the bulb to heat to temperatures as high as 1,000ºC (1,832ºF). That ultra-hot air is then used to run a turbine generator.
The plant has an output capacity of 100 kilowatts-equivalent – reportedly enough to power 60 to 80 homes.
Unlike some other systems that use water, oil or mineral salts as their solar heat-carrying medium, the Tulip uses atmospheric air. It also doesn't require any cooling medium – an important consideration in areas where water is scarce. At night, when there’s no warming sunlight, it can be switched over to generate electricity using fuels such as diesel or natural gas – it can even operate in a hybrid mode when the sunlight is intermittent, using both fuel and solar-heated air at the same time.
The Almeria plant took approximately seven months to build, and is designed to operate for at least 25 years. AORA hopes to have additional demonstration plants operational in other parts of the world soon.
The AORA video below provides a run-down on the workings of the Tulip plant.