AORA Solar, an Israeli developer of applied ultra-high temperature concentrated solar power (CSP), will be opening its second-ever gas-turbine solar thermal power station in Almeria, Spain, on February 7. Their first such plant was opened at Kibbutz Samar in the Arava Desert in near Eilat in June 2009.
The roughly 2,000-square-meter facilities are capable of supplying 100 kilowatts of electricity per hour to their respective regions and about 170 kilowatts of heat energy as a byproduct, which in the case of Spain will be used to power an adjacent desalination facility.
“It’s there to demonstrate the viability of the design, as is the one in Samar,” AORA CEO Zev Rosenzweig told, noting, for comparison’s sake, that 100 kilowatts have the ability to power about 60 to 80 homes.
The AORA system operates on a hybrid basis, in which it can operate with solar-only mode, fuel-only mode (which is used at night) or a combination of the two, on a cloudy day, for example. While both the Almeria and the Samar plants are using diesel fuel as their second source, the plan is to switch the Samar facility to natural gas as soon as supplies become readily available.
Meanwhile, the company is also looking at other options for the facilities, such as bio-gas, which would make use of sources such as cow manure and vegetable waste, according to Rosenzweig.
“The switch from one type of fuel to the other is relatively simple,” said Pinchas Doron, AORA’s chief technology officer. “You don’t really need to tear down the entire plant to switch fuels once natural gas or bio-gas becomes available.”
There is no need for a storage system, as the facility is constantly able to produce energy due to the dual sources. Storage systems, Rosenzweig explained, are also quite inefficient and consume a lot of energy when taking the supply in and out of storage.
Rosenzweig explained that due to the modular design of the facilities, the system also takes up much less space than a photovoltaic field or other types of concentrated solar power. The base unit, “like Legos,” can be duplicated to increase the size of a system, without having to enlarge the surface area of the original piece and without requiring contiguous or flat land, according to Doron.
“We can distribute units in several patches, not really adjacent to each other, and manage and run them as a single plant,” Doron said. “It’s not just less land – it’s much more flexibility.”
Meanwhile, each of the 52 panels – called heliostats – in the unit can track the motion of the sun along two axes and then directs the sun’s light to a 35-meter-high tower that houses a solar receiver as well as a gas turbine, based on technology developed at the Weizmann Institute of Science.
The receiver uses the sun’s rays to heat the air to 1,000 degrees Celsius and directs the resultant thermal energy into the turbine, which converts it into electricity, according to AORA.
“The units are relatively small, so therefore the distance from the mirror to the tower is small,” Rosenzweig said.
The company will also be using their updated expertise gained from constructing the brand-new Spanish facility to retrofit the Samar plant, according to Rosenzweig.
AORA’s decision, like that of many other Israeli renewable energy innovators, to expand to markets outside of Israel is a testament to the problems the business faces at home, he said. While he can receive 26 euro cents for generating a kilowatt-hour of solar electricity in Spain, the Israeli system would compensate him with only $0.20 for that same amount of energy, Rosenzweig said.
“What really upsets us is that you can get much more money using Chinese photovoltaic panels in Israel than using Israeli technology to generate solar electricity in Israel,” he added.
While providing higher feed-in tariffs up front may be expensive for governments, countries like Spain and Italy are doing so in order to promote long-term renewable energy development for their countries, which will eventually reduce their reliance on foreign oils, Rosenzweig explained.
The Israeli government, he said, needs to “sit down and re-examine [its policies] from scratch,” so that it doesn’t deter its own innovators from seeking markets elsewhere.
“Whoever sets the rates needs to have a longer-term plan, and the rates should reflect what the government hopes to achieve by providing feed-in tariffs,” he said. “Israel has greater solar assets but lacks a coherent strategy for exploiting them.”
SHARON UDASIN, www.jpost.com