MinWaterCSP aims to reduce the annual water consumption of a CSP plant through a number of complementary measures while maintaining or even improving thermal efficiency and reducing capital costs. This is done through a holistic combination of next generation technologies in the fields of hybrid dry/wet cooling systems, axial flow fans, wire structure heat transfer surfaces, comprehensive water management plans, mirror cleaning techniques and optimized cleaning schedules. Up to now, the MinWaterCSP project partners have already achieved excellent results.
The project consortium designed a novel hybrid dry/wet cooling system which reduces water evaporation losses by between 75% and 95%, compared to a solely wet cooling system. In addition, an axial flow fan was developed, manufactured and installed at the Eskom Matimba Power Station site in South Africa. Three prototype scale-model fans were furthermore designed and evaluated for a typical air-cooled condenser installation using Computational Fluid Dynamics (CFD). Fan noise levels were also evaluated.
Picture 1: Fan installation at Matimba (photo: Notus Fan Engineering)
A novel wire surface heat exchanger concept offers – compared to conventional solutions – a potential saving of 10% of material at equal thermal and fluid dynamic performance and a reduction in life-cycle environmental impact, resulting in lower investment costs for cooling systems used in CSP plants.
For CSP plants, comprehensive water management plans in different locations around the world are developed to assess the impact of the design improvements achieved in a complete CSP system context. Moreover, simulation models for overall CSP plant water consumption were developed.
For the cleaning process, a reduction of 25% of the existing water consumption by improving the mirror cleaning process seems achievable with a positive impact on operating costs for contractors, which leads to a significant positive impact in arid areas.
Picture 2: Cleaning truck of partner ECILIMP Termosolar (photo: GEMASOLAR Plant, property of Torresol Energy©SENER, Cleaning Technology property of ECILIMP)
For solar collector cleaning, different cleaning prototypes have been designed and constructed – truck-based for parabolic troughs and heliostats and a new cleaning robot for Fresnel collector applications. Furthermore, prototypes for collector reflectance monitoring have been installed.
A test rig for cooling system fouling tests has been installed in Morocco. In addition, a novel full-scale test facility for the hybrid cooling system and the CSP cooling fan development is currently being built in Stellenbosch, South Africa.
Picture 3: Fouling test rig, Green Energy Park in Morocco (photo: IRESEN/ENEXIO)
Project partner Fraunhofer ISE has continued the development of its CSP plant simulation software ‘ColSim’ incorporating various improved modelling methodologies derived from the MinWaterCSP project. The models simulate water streams throughout the CSP plant enabling the quantification of water consumption, water quality, treatment processes and the required energy for treatment.
MinWaterCSP – achieving positive economic, environmental and societal impacts on the CSP branch and beyond
The expected impact of the MinWaterCSP project is to reduce cooling system capital and operating costs. Net power output could be improved while saving water. As a result, locations with limited water supply can expect to benefit from CSP technology, reducing dependency on fossil fuels. Similarly, a reduction in the effects on the environment during the entire life-cycle of a CSP plant can be expected. Finally, the MinWaterCSP consortium aims to make CSP more attractive for investment purposes in order to drive growth in the CSP plant business as well as create new jobs.