MR on-load tap-changers bring Spanish sun to power grid


Power generation from renewable sources is becoming increasingly important particularly when it comes to climate and environmental protection. Power from alternate sources such as sun, wind and water has been promoted in Germany ever since the "Renewable Energy Law" was passed in the year 2001. Photovoltaic (i.e., the process of obtaining electrical current from sun energy) is the solution that is most often used here in this country. Following the German example, many other countries - including Spain - have passed laws subsidizing renewable energies. Different from Germany, the Spanish law divides solar energy into two types. One is photovoltaic and the other is the conversion of solar energy into electrical energy using thermal processes.

In contrast to photovoltaic, the electrical energy is created by thermal processes and not directly by the photoelectrical effect. The first step is a bit like the solar thermal energy process used for heating industrial water except that much higher temperatures are required. These temperatures are not achieved by the sun shining directly on a collector. Instead the sun rays are bundled with a mirror (a so-called parabolic reflector) on an absorber through which a liquid is circulating which is heated to far in excess of 400°C, depending on the technology being used. The procedure functions like a conventional power plant during the second step. The liquid is used to generate steam via a heat exchanger and this steam drives a turbine. A generator is connected to the turbine to generate electrical energy. As we are all familiar with, a transformer then feeds the energy to the power grid. And on-load tap-changers ensure that the power supply always remains constant.

The Maschinenfabrik Reinhausen (MR) is involved in many of these projects - for example, the Andasol 3 thermal power plant which is currently being built in Granada. The German companies Solar Millenium and MAN Ferrostaal are also involved in the configuration and implementation of this plant. After its commissioning which is planned for the beginning of 2011, Andasol 3 will generate about 150 GWh of power with a power plant capacity of 50 MW per year. A transformer from the Starkstrom-Gerätebau GmbH in Regensburg which will be delivered in May of 2010 will feed this power to the grid. And inside this transformer an OILTAP® M will make sure that the power supply remains steady.

Two solar thermal plants with MR on-load tap-changers are already in operation in Extremadura (in south western Spain). A VACUTAP® VR is in operation in La Florida and a VACUTAP® VV is ensuring steady voltage conditions in La Dehesa. Here a TAPCON® 230 handles the voltage regulation. Additional MR on-load tap-changers and also de-energized tap-changers are being used in projects in Lebrija near Cádiz and in Puertollano in Castilian La Mancha.

MR's involvement in these innovative projects proves that the MR is also the right partner when it comes to new and promising technologies.

 

c.poschenrieder@lu.reinhausen.com