Technology‎ > ‎

Towering tulips help solar power flower

posted 2 Apr 2012, 06:11 by Mpelembe   [ updated 2 Apr 2012, 06:11 ]

An Israeli energy company is taking flower power to a new level. The company, AORA, is using tulip-shaped towers to concentrate solar energy into a high temperature gas that can be used to power entire communities. Their newest plant has just opening Spain.

Hidden in the bizarre lunar landscape of the Tabernas desert in Andalusia stands a 115-foot-high yellow tulip that can generate enough power for 35 houses.
Israel's energy innovator company AORA unveiled in February a small demonstration solar power plant, roughly two square kilometers in size, in the Centre for Solar Energy Exploration in Almeria, Spain.

About 50 mirrors or heliostats track the sun's movement, reflecting light onto the collector tower, which heats air to temperatures of up to 1.000 degrees Celsius.

The heated air is channeled into a combustion chamber, where it expands and powers a turbine, producing electricity.

Plant operator Helio Escrig said the installation saves money and is environment-friendly.

"This technology requires a small heliostat field and a small tower to produce energy. The idea is to make it modular and scalable, that is to say, we can fit the necessities or the demanded power. Another benefit is that the heat transfer fluid is air instead of oil or mineral salts, atmospheric air that we don't have to purchase. Neither we need to cool it so we there is no water consumption," Escrig said.

What is unique in AORA's design is a gas turbine that can handle super-high temperatures and then work off external fuel, which can also be renewable fuel, when there is insufficient sunlight. That allows the solar power plant to produce continuous electricity, a boon for off-grid locations where there is no alternative power source. And even where there is a grid, the unpredictability of solar power is a headache for network operators.

The process also creates a by-product of some 170 kilowatts in power for heating water for homes or factories, said project manager Lauren Elbaz.

"We would like to demonstrate the capability of the various applications it could have and the installation's thermal potential. In a near future perhaps we can work in water desalination, air conditioning both heat and cooling and other industrial processes as drying," Elbaz said.

AORA, whose original technology was developed in Israel's Weizmann Institute of Science in the 1980's, constructed its first hybrid solar power station on a half-acre (0.2 hectare) plot in Israel's Negev desert, where companies are competing to create more efficient technologies and tap into the multi-billion dollar clean energy market.

The plant in Kibbutz Samar can produce 100 kw, enough energy to power about 40 houses, said Pinchas Doron, AORA's chief technology officer.

"The ways that our system works is basically the turbine that generates the electricity needs to get the heat from the sun. The way it gets the heat from the sun is by refelecting it from a field of mirrors that track the apparent motion of the sun, all on to the top of the tower where the, we call receiver is that uses this radiation, this concentrated sunlight to heat the air to close to 1,000 degrees (celcius)," said Doron from AORA's headquarters in Rehovot in central Israel.

Traditional photovotalic panels, Doron says, can generate power only when there is sunlight. By contrast, AORA's system is hybrid, so it can run around the clock and make use of the access heat.

A 100 kw plant using traditional photovoltaic panels, which can have up to 15 percent efficiency, would also need twice the land than its hybrid-solar plant running at 28 percent solar efficiency, AORA said.

The module looks like a smaller version of solar "power towers" being developed in the United States and Europe, with 30 large mirrors reflecting sunlight onto a generator on top of a 30 meter (90-foot)-high tower.

"We want to have flowers all over where there is sun and power comminties basically wherever there is sufficient sun and where people need, not just electricity, but where people need an energy solution," siad Doron.

AORA hopes to expand its operations to lands across the Mediterranean, North America, South Africa, India and China.

Financed by both private and European researching funds, the company has raised $28 million USD and seeks a further $35 million - $40 million USD investment.

"We're still in the research phase of putting up plants to prove that they work. The money we're looking to raise is basically to allow us to grow to the point where we can reach the stage of commercialization where we can sell plants," said Zev Rosenzweig, president and CEO of Aora Solar.

AORA said the cost of their electricity is competitive with other solar technologies: between $3,500-$5,000 USD per installed kilowatt, meaning each 100 kw hybrid plant may cost up to $500,000 USD. Total production costs depend on the price of the external fuel.