By Rachel Neiman May 13, 2009
Rising up, like a mirage in the middle of the desert outside Eilat, is a giant yellow tulip in whose heart lies a massive crystal. Surrounding it: a field of mirrors that slowly move back and forth, following the sun.
Hallucinatory though it may sound, this is no mirage. The tulip is actually a solar tower with an aperture that directs sunlight into a solar receiver that drives a high-powered turbine, and the 30 tracking mirrors below are called heliostats.
It's an ambitious project initiated by Israeli company AORA to construct the world's first solar-thermal powered gas turbine station. The plant, with its distinctive 30-meter high tulip-shaped tower, is now nearing completion at Kibbutz Samar in Israel's southern Arava region.
AORA, of Israeli EDIG group, is a developer of applied ultra-high temperature concentrating solar power (CSP) technology. The breakthrough of CSP is that it can power a 100kW gas micro-turbine; other solar technologies currently available can only power much larger steam turbines. AORA says it is the worlds' first company to commercialize the use of a solarized gas turbine engine.
The government recently showed support when Minister of National Infrastructures, Binyamin Ben Eliezer signed AORA's license provide solar electricity to the national grid -- the first such license to be granted by Israel to solar-thermal technology.
Being able to run the equivalent of a jet engine on solar power, means the system is efficient at far smaller power blocks, Yuval Susskind, COO of AORA, explains to ISRAEL21c. This enables smaller scale projects that require less land and shorter towers (30m vs. 70-120m and more), and which are easier to build, finance and operate.
"Israel has all the climate conditions, but we don't have huge available tracts of land. AORA is the first to bring the size of a solar field down to something like a soccer pitch or a baseball diamond," says Susskind.
Business looks bright - abroad
The installation at Samar will be the model for many more to come, says Haim Fried, CEO of AORA, and will include the framework for selling power to the national grid over a long-term period.
The company expects to begin power generation any day. Once it begins generating power, Fried says, the Samar unit will provide 100kW electric power to the grid, as well as 170kW thermal power - enough to supply 50 households at an average of 2kW per household. "That's the average use in Israel. The US is a bit more," he explains.
Fried notes that selling power to the local grid close to the customer base is more efficient because there is no need to step up and down voltage, as is done when transmitting power from a central power station. By generating locally, the power is fed in low voltages, via the local distribution grid, for standard domestic use in the home. It also relieves the load on the high voltage distribution grid.
Location is key, he adds because AORA's installations require direct radiation. "The set up cost is the same in the Arava or Tel Aviv but for the same investment I get more direct sunshine at Samar, so I'll get more power out of it."
The company's business plan has two profit centers: in Israel it will sell power to the national grid through partnerships. Outside Israel, the company will set up joint ventures with local partners to build solar power stations and sell clean energy to the grid.
Costs haven't been finalized yet, but Fried says installations will be competitively priced and estimates that AORA will become profitable after selling 20 units.
"We're also probably going to do a joint venture in Spain," he adds. "We want to do more in Israel but there's a problem with the feed-in tariffs, which are too low. In Spain, they pay 29.9 eurocents, which is much more favorable. If Israel doesn't change the rates then we'll have to do more business outside."
Sunny technology
The AORA system is hybrid, meaning it can run on solar, as well as almost any alternative fuel, including biogas, biodiesel and natural gas. Being located in an agricultural community such as Samar, Susskind points out, means ready access to unlimited amounts of biogas, courtesy of the kibbutz cowshed. "So it can run on sunshine during the day, biogas at night and be operational 24 hours a day," he says.
The system is also modular and scalable; more base units - each comprising a tulip tower and 30 heliostats on a half-acre of property - can be added as demand grows.
Modularity enables each unit to be located independently with no need for one large, flat, contiguous expanse of land. Strung together, the units can form a utility-scale power plant. Being modular also means greater reliability, the company states, as servicing a single base unit does not require a complete shutdown.
The key components of AORA's Power Conversion Unit (PCU) are the micro-turbine and the solar receiver, whose technology resulted from collaboration with the Weizmann Institute and Rotem Industries.
The patented receiver uses the sun's energy to heat air to a temperature of 1,000 degrees Celsius and direct this energy into the turbine. The turbine then converts this tremendous thermal energy into electric power.
The solar receiver and some other key components are proprietary technologies and will always be manufactured in Israel, says Fried. However, other components, such as the tower and heliostats, are made of simple materials and can be manufactured wherever a base unit is to be set up according to AORA's specifications.
The company unveiled the Samar project in February, at the annual Eilat-Eilot Renewable Energy Conference. "The response was very positive - which is a great compliment because of the high professional level there," says Fried.
"Greentech has to look good"
AORA's tulip is painted bright sunny yellow. Susskind says this was because the dusty red of the Arava hills overpowered the gold color. "One reason for selecting Samar was its proximity to the highway. I want every kid to see this tower when they're heading for a family vacation in Eilat," he says.
The company hired architect Haim Dotan to design the tower. "We didn't think we could afford it but we met with him, and told him about our vision: that there would be many towers like this all over the world. He was so excited about the project that he said he would do it in any case. He said it would make the desert bloom - that's why it's in the shape of a flower. He loves the desert and wants it to be beautiful."
AORA also has a vision of setting up a roadside attraction for tourists: an alternative energy education center that will showcase not just the company's own technology, but other cleantech being developed and tested in the region as well. The company has already been in talks with the regional council, which is interested in the project.
After the Samar facility is completed, AORA plans to expand into larger scale power generating plants of 5MW and more. "By late 2009, we plan on setting up our first international installations in strategic markets," says Fried. These include the Mediterranean, southern Europe, Australia, California, Arizona and the US Sun Belt states. At a later stage, the company aims to enter the African market. "We view China - where we already successfully constructed and operated a pilot unit - Africa and other remote regions as the true market for the AORA system," says Fried. |
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