Concentrating Solar power plants - How to Achive Competiveness

Abstract

Electricity from solar thermal power plants is environmentally friendly, it helps to protect the climate and to save fossil resources. If the solar thermal power plants are equipped with thermal storage facilities, they are capable to deliver power even at times without solar radiation. Though the costs of this kind of solar electricity are lower than those from photovoltaic cells, they cannot compete with the generation costs from fossil power plants today. The ECOSTAR study shows that it is possible to overcome this drawback. This study was partly financed by the European Union and conducted by research organisations from Germany, Spain, France, Israel, Switzerland and Russia. The Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR) was the project leader and the VGB PowerTech e.V. was also involved, particularly by performing an independent assessment of the results. Seven different solar thermal technologies for electricity production have been investigated within the study. The starting point was the definition of 7 reference systems, describing today’s state-of-the-art and cost. Technical improvements and innovations for the different technologies have been analysed in terms of their impact on system efficiency, investment costs as well as operating and maintenance costs. An unexpected result was that the innovation driven cost reduction potential of all systems is in the range of 30-40%. Further cost reduction of 17% due to scale-up and extended operation times (due to thermal storage integration) seems possible. Volume production of the components may add savings of about 14%. These accumulated cost reductions can bring down costs of electricity from today’s 12 to 18 cents€/kWh to 5 to 7 cents€/kWh depending on the radiation resource. This is regarded as competitive cost level for dispatch able mid-load power without carbon dioxide emissions. About 10 – 15 years are necessary for such a development, in parallel to a continuous market implementation. The study points out those innovations showing the greatest cost reduction potential and gives priorities for further R&D. A general recommendation is that short- and mid-term research should focus on modular components like concentrators or modular receivers. Medium and long term development is needed mainly in the area of thermal storage and the integration of larger and more efficient power cycles. Both pathways must be followed in order to reach the cost target. Concentration of research or demonstration plant funding on certain technologies should be avoided because this would lower the cost pressure caused by competition between the different technologies.