New Solar Technology to be Implemented Under a U.S.-Israeli Agreement

The novel U.S.-Israeli system uses special optics and an innovative air receiver developed by the Weizmann Institute. These reflect, concentrate, and convert sunlight to provide the high temperatures necessary to directly power gas and steam turbines in a combined cycle and thus generate electricity. The flexibility to operate on either solar, gas, or a combination of solar and gas will provide operational flexibility and guarantee electricity even during inclement weather. The application of combined cycles assures very high efficiency in all modes of operation. Recent market assessments indicate that this new technology has the potential of wide international applications.
 

The signing of the agreement was announced today at the U.S. Space and Rocket Center in Huntsville, Alabama.

 

In less than three years, the U.S.-Israeli team will develop an operational 200-300 kilowatt system to be located at the Weizmann Institute's solar research facility, the Canadian Institute for the Energies and Applied Research. This system will be equipped with highly reflective mirrors (heliostats), which track the sun in two axes and reflect sunlight up to another reflector atop a central tower. This reflector will then redirect the sunlight back down to a matrix of optical concentrators, capable of concentrating the light 5,000 to 10,000 times, compared to natural sunlight reaching the earth. The concentrated radiation will then enter a unique group of solar receivers, located on the ground, which will heat up compressed air to be used for driving the turbogenerator that produces electricity.The pilot system's advantages stem from a unique combination of technologies. Firstly, the production facilities, including the concentrators, receivers and turbogenerator, are located on the ground rather than at the top of the tower (as they were in previous systems). This innovation will make construction of the tower, whose sole function will be to support the reflecting mirror, significantly simpler and cheaper.
 

Secondly, the sophisticated design of the concentrators, based on pioneering research at the Weizmann Institute, will make it possible to concentrate sunlight sufficiently in order to heat the air to the temperature needed for driving advanced gas turbines. A third innovation is the use of the Weizmann Institute-designed solar receiver (nicknamed "Porcupine") that contains hundreds of ceramic pins arranged in a geometric pattern that maximizes the collection and use of sunlight. Compressed air that flows across the pins is heated and channeled to the gas turbines. Sunlight enters the device through a special cone-shaped quartz window that can withstand higher pressure than can a similarly designed steel cone.

As stated, many of the technologies to be implemented in the new solar power station originated at the Weizmann Institute. Following initial stages of the research, the Institute scientists were joined by researchers from Rotem Industries, who collaborated with Weizmann on design and construction of the first prototype of the "Porcupine" receiver, as well as on consolidating the design of its optical components.

 

Most of the research conducted up to this stage was supported by the Chief Scientist of the Ministry of Energy (now the Ministry of National Infrastructures). The transfer of Weizmann Institute technology to industry has taken place through Yeda Research and Development Co. Ltd.When the research reached a relatively advanced stage, the Consolar Ltd. consortium of Israeli companies and academic institutions was set up. It is supported by the Chief Scientist of Israel's Ministry of Industry and Trade, under the Ministry's Magnet program, whose aim is to promote the application of new, emerging technologies. Its members are Rotem Industries, Ormat Industries, Silver Arrow, the Israel Aircraft Industries, the Weizmann Institute of Science, Tel Aviv University and Ben-Gurion University of the Negev.
 

In 1994, President Clinton and the late Prime Minister Rabin announced the creation of the USISTC to enhance cooperation and create technology-based jobs for the 21st Century.Initially, each nation committed $15 million over the next three years to fund technologically innovative projects that will produce significant economic benefits. Efforts of the USISTC are coordinated by the U.S. Department of Commerce and Israel's Ministry of Industry and Trade.The McDonnell Douglas-Rotem-Ormat collaboration was initiated within the framework of the USISTC to promote binational undertakings in order to implement the technologies developed by Consolar Ltd. The collaboration's ultimate goal is to develop an industrial product, that is, to build solar power stations that will produce electricity at competitive prices compared with those of existing power stations.

 

The signing of the collaboration agreement, as stated above, was announced today in Huntsville, Alabama. The pilot power station at the Weizmann Institute, whose construction represents the first stage of that collaboration, will use solar energy to drive a 200-300-kilowatt turbine generating electricity.

 

Based on technologies to be tested and developed in this project, larger-scale commercial power stations, capable of generating hundreds of kilowatts to tens of megawatts of power, will be set up in the future.These stations will be sold as "complete products" to various countries and organizations. In the course of the development, McDonnell Douglas is the team leader and is responsible for system engineering and integration, heliostat field, master control system, tower and tower reflector.

McDonnell Douglas previously developed the 10 megawatt Solar One solar power generation demonstration plant using a heliostat field to reflect sunlight to a receiver mounted on a central tower to produce steam for a steam turbine in the Mojave Desert during the 1980s. Ormat is responsible for the power conversion system and the fluid loop integration. Ormat specializes in the design, manufacture and world-wide installation of innovative power systems and plants, including 350 MW of renewable energy (geothermal and solar).Rotem is responsible for the air receiver and its associated optics which transforms the concentrated solar energy into high pressure, high temperature air. Rotem brings to the project many years of experience in optical design, high temperature materials and engineering.

 

The Weizmann Institute and its commercial arm, Yeda, are responsible for the transfer of their unique solar technologies to industry and will host the prototype system at their solar test facility. Since the construction of that facility some 10 years ago, Weizmann has accumulated significant experience in the development and utilization of highly concentrated solar energy.