The Ashalim Solar Thermal Power Station is being built and will be operated by Megalim Solar Power Ltd. General Electric is responsible for the engineering behind the project, while Bright Source is providing the advanced solar field technology.
According to EcoWatch, the solar power station will have over 50,000 computer-controlled heliostats or mirrors, to track the sun and reflect its rays to a boiler on top of the tower. The boiler will create super-heated steam that will be fed to a turbine, generating electricity.
The electricity generated by the power station will supply 120,000 homes with clean energy. When completed by the end of 2017, the power station will help Israel to achieve 10 percent of its electricity production from renewable energy sources by 2020.
At this time, renewable energy sources make up about 25 percent of Israel’s energy mix. The Ashalim plant will increase Israel’s energy security and reduce the country’s dependence on fossil fuel imports from other countries.
General Electric, a Megalim shareholder, explained the advantages of the power station in a brochure: “Compared to solar photovoltaic (PV) applications, direct steam CSP has the advantage of being able to produce electricity for longer periods of time during the solar hours. The ability to operate during peak demand times reduces the need for utilities to build power plants to operate only during peak times—thereby lowering the overall system’s electricity production costs.”
The Ashalim Plant is situated on three plots, with a further expansion to a fourth plot in the works for 2018. When all four plots are online, they will be able to generate almost 310 megawatts of power, enough to supply Israel with 16 percent of its energy needs, or about five percent of Israel’s’s population.
Concentrating Solar Power Plants
The Ashilim Solar Thermal Power Station makes use of a technology to concentrate solar power (CSP). CSP plants use mirrors to concentrate energy from the sun to drive conventional steam turbines to create energy. While there are several mirror configurations available to concentrate the sun’s rays, the Ashilim project is using heliostats that are computer-controlled.
The flat mirrors track the sun along two axes to focus its rays on a receiver at the top of the tower. That focused energy is then used to heat a transfer fluid (typically molten salt) to over 1,000 degrees Fahrenheit to produce steam to run a central power generator.
When using molten salt (40 percent potassium nitrate, 60 percent sodium nitrate) as a transfer fluid and as a thermal energy storage medium, it is fairly easy to incorporate energy storage, according to the Solar Energy Industries Association. This method allows power to be generated on a 24-hour basis.
