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 isactually a solar tower with an aperture that directs sunlight into asolar receiver that drives a high-powered turbine, and the 30 trackingmirrors below are called heliostats.
It’s an ambitious project initiated by Israeli company AORAto construct the world’s first solar-thermal powered gas turbinestation. The plant, with its distinctive 30-meter high tulip-shapedtower, is now nearing completion at Kibbutz Samar in Israel’s southernArava region.
AORA, of Israeli EDIG group, is a developer of applied ultra-hightemperature concentrating solar power (CSP) technology. Thebreakthrough of CSP is that it can power a 100kW gas micro-turbine;other solar technologies currently available can only power much largersteam turbines. AORA says it is the worlds’ first company tocommercialize the use of a solarized gas turbine engine.
The government recently showed support when Minister of NationalInfrastructures, Binyamin Ben Eliezer signed AORA’s license providesolar electricity to the national grid — the first such license to begranted 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, YuvalSusskind, COO of AORA, explains to ISRAEL21c. This enables smallerscale 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 hugeavailable tracts of land. AORA is the first to bring the size of asolar field down to something like a soccer pitch or a baseballdiamond,” 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 forselling power to the national grid over a long-term period.
The company expects to begin power generation any day. Once itbegins generating power, Fried says, the Samar unit will provide 100kWelectric power to the grid, as well as 170kW thermal power – enough tosupply 50 households at an average of 2kW per household. “That’s theaverage use in Israel. The US is a bit more,” he explains.
Fried notes that selling power to the local grid close to thecustomer base is more efficient because there is no need to step up anddown voltage, as is done when transmitting power from a central powerstation. By generating locally, the power is fed in low voltages, viathe local distribution grid, for standard domestic use in the home. Italso relieves the load on the high voltage distribution grid.
Location is key, he adds because AORA’s installations require directradiation. “The set up cost is the same in the Arava or Tel Aviv butfor the same investment I get more direct sunshine at Samar, so I’llget more power out of it.”
The company’s business plan has two profit centers: in Israel itwill sell power to the national grid through partnerships. OutsideIsrael, the company will set up joint ventures with local partners tobuild solar power stations and sell clean energy to the grid.
Costs haven’t been finalized yet, but Fried says installations willbe competitively priced and estimates that AORA will become profitableafter 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-intariffs, which are too low. In Spain, they pay 29.9 eurocents, which ismuch more favorable. If Israel doesn’t change the rates then we’ll haveto do more business outside.”
The AORA system is hybrid, meaning it can run on solar, as well asalmost any alternative fuel, including biogas, biodiesel and naturalgas. Being located in an agricultural community such as Samar, Susskindpoints out, means ready access to unlimited amounts of biogas, courtesyof 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 – eachcomprising 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 noneed for one large, flat, contiguous expanse of land. Strung together,the units can form a utility-scale power plant. Being modular alsomeans greater reliability, the company states, as servicing a singlebase unit does not require a complete shutdown.
The key components of AORA’s Power Conversion Unit (PCU) are themicro-turbine and the solar receiver, whose technology resulted fromcollaboration with the Weizmann Institute and Rotem Industries.
The patented receiver uses the sun’s energy to heat air to atemperature of 1,000 degrees Celsius and direct this energy into theturbine. The turbine then converts this tremendous thermal energy intoelectric power.
The solar receiver and some other key components are proprietarytechnologies and will always be manufactured in Israel, says Fried.However, other components, such as the tower and heliostats, are madeof simple materials and can be manufactured wherever a base unit is tobe set up according to AORA’s specifications.
The company unveiled the Samar project in February, at the annualEilat-Eilot Renewable Energy Conference. “The response was verypositive – which is a great compliment because of the high professionallevel there,” says Fried.
“Greentech has to look good”
AORA’s tulip is painted bright sunny yellow. Susskind says this wasbecause the dusty red of the Arava hills overpowered the gold color.“One reason for selecting Samar was its proximity to the highway. Iwant every kid to see this tower when they’re heading for a familyvacation in Eilat,” he says.
The company hired architect Haim Dotan to design the tower. “Wedidn’t think we could afford it but we met with him, and told him aboutour vision: that there would be many towers like this all over theworld. He was so excited about the project that he said he would do itin any case. He said it would make the desert bloom – that’s why it’sin the shape of a flower. He loves the desert and wants it to bebeautiful.”
AORA also has a vision of setting up a roadside attraction fortourists: an alternative energy education center that will showcase notjust the company’s own technology, but other cleantech being developedand tested in the region as well. The company has already been in talkswith the regional council, which is interested in the project.
After the Samar facility is completed, AORA plans to expand intolarger scale power generating plants of 5MW and more. “By late 2009, weplan on setting up our first international installations in strategicmarkets,” says Fried.
These include the Mediterranean, southern Europe, Australia,California, Arizona and the US Sun Belt states. At a later stage, thecompany aims to enter the African market. “We view China – where wealready successfully constructed and operated a pilot unit – Africa andother remote regions as the true market for the AORA system,” saysFried.
This article is reprinted with permission from ISRAEL21c – www.israel21c.org.