Concentrating Solar Power and Desalination Plants

With the current strong development of solar energy projects around the world, concentrating solar power and desalination (CSP+D) could be the next significant technological breakthrough. The main reason for this is that it is internationally recognized that power and water supply will be two major issues mankind will have to face and solve during the present 21st century. During the coming decades, the oil era will come to an end, and it is not yet clear today which source of energy will replace it. At the same time, water scarcity is already a global problem which will become crucial during the first half of this century, seawater desalination often being the only alternative source for this element essential to life.

Despite the advances in energy efficiency during the last decade, seawater desalination continues to be an intensive fossil-energy consumer. In a context of an oncoming energy crisis due to the end of the oil era, water problems are expected to substantially worsen. And vice versa, due to the close relationship between water and energy issues, water shortages are also expected to contribute to increasing power problems. In addition to all this, environmental considerations such as global warming will surely add significant pressure. In this scenario, renewable energies are rapidly increasing their contribution to the global mix, in which solar energy is clearly the one with highest potential.

Therefore, the integration of solar desalination in solar thermal power plants makes complete sense as it is extremely probable that anywhere there is high enough solar radiation to justify a CSP plant, water would be a more valuable and necessary product than power. Although use of the electricity generated to drive a conventional reverse osmosis (RO) process is possible, multi-effect distillation (MED) seems to be an even more suitable process for integration in CSP plants, using the exhaust steam from the turbine to drive the MED process, part of it as the power cycle cooling system and, potentially, significantly increasing overall efficiency.

The objectives of this Subtask are:

  1. To collect existing knowledge and experience on hybrid power and desalination plants for application to hybrid solar power and desalination plants of MW-size;
  2. To analyze and determine the main technological characteristics of hybrid solar power and desalination plants;
  3. To promote collaborative initiatives in specific assessment of technical and economic feasibility of hybrid solar power and desalination plants, and also identify potential follow-up demonstration case studies.