Environment

AORA's Tulip solar power system is more than hot air

AORA's Tulip system uses the sun's rays to heat air, which is then used to spin a turbine, creating electricity
AORA's Tulip system uses the sun's rays to heat air, which is then used to spin a turbine, creating electricity
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Sunlight is concentrated onto the Tulip's bulb
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Sunlight is concentrated onto the Tulip's bulb
The heliostats used to focus the sunlight onto the Tulip
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The heliostats used to focus the sunlight onto the Tulip
At night, the Tulip can generate electricity using conventional fuel
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At night, the Tulip can generate electricity using conventional fuel
The Tulip is scalable, so systems can be built to fit individual users' needs
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The Tulip is scalable, so systems can be built to fit individual users' needs
The Tulip doesn't require any cooling medium, which is an important consideration in arid regions
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The Tulip doesn't require any cooling medium, which is an important consideration in arid regions
AORA's Tulip system uses the sun's rays to heat air, which is then used to spin a turbine, creating electricity
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AORA's Tulip system uses the sun's rays to heat air, which is then used to spin a turbine, creating electricity

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.

The Tulip is scalable, so systems can be built to fit individual users' needs
The Tulip is scalable, so systems can be built to fit individual users' needs

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.

Source: AORA

Aora Solar Energy Residential

11 comments
Carlos Grados
So in theory they could heat up the air with geothermal too?
Slowburn
The hybrid model is much more practical than any stored energy system.
Slowburn
re; Carlos Grados There are more efficient ways of converting geothermal energy into mechanical energy than through a heat exchanger into air that is running through a gas turbine. Stirling cycle springs to mind. Also tappable geothermal usually is not nearly that hot.
Mr Stiffy
Basically this is a jet engine with an extended turbine shaft between the compressor and the expandor stages, using a solar concentrated air heater, instead of a combuster. I have been designing this kind of gear for years... Kudos - simple and if you use a closed loop cycle on the air, you can use all that heat energy for other purposes.
Slowburn
re; Mr Stiffy If you use a closed loop you loose efficiency in the generation of electricity.
Burnerjack
Apparently, NIMBY doesn't exist in these other countries. Good for them! I am curious as to why a brine solution or even some hypertutechtic salt isn't used, only because of the btu/volume. Even a Rankine cycle would seem better by definition. I defer to you, Mr. Stiffy, as you design these, I hope you could shed light on this curiosity.
Burnerjack
Slowburn, If one were to use the high(er) temp exhaust to preheat the medium prior entering the target receiver, wouldn't that INCREASE the overall efficiency?
Mr Stiffy
@Slowburn...... NO - you extract the heat out of the working fluid for other purposes......
Slowburn
re; Burnerjack Yes. It is a fairly common design feature on large ground based gas turbines but it is still on open system.
blue7053
System efficiency is in 'how much energy you can take out in a cycle'. If air is heated to 1000 degrees, and cooled to 200 during the power stroke, then reheated, 800 degrees of power is taken out every cycle. Very efficient. The re-heating is the problem. Energy transfers to liquid (coefficient of conductivity) at an rate of '1' and to air at an rate of '.5'. very inefficient. If your energy is free, however, it works.
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