NEWSUN - Nexus of Electricity and Water Supply for Urban Needs

The effects of global warming are already severely recognizable. While some regions are threatened by increasingly frightening storms and heavy rainfalls, other areas suffer from drought. According to projections by the OECD, 47% of the world’s population will live in regions with insufficient drinking water resources. Already since 2015, more than 80 countries have been confronted with water scarcity and a great share of the population depends on desalination for their water supply. The main shortcoming of such desalination facilities lies in the high specific energy demand, which so far, has mainly been covered by fossil fuels. This process favors the Middle East with its rich oil reserves but represents a clear conflict with today’s climate change targets. Thanks to the project NEWSUN (Nexus of Electricity and Water Supply for Urban Needs) it will be possible to run desalination facilities entirely energy self-sufficient and sustainable. Solar energy is harvested using parabolic through concentrators, and the core of the system, the so called Hybrid-Absorber converts the radiation to electricity and heat. The desalination process is based in the highly efficient and maintenance-free Multi Effect Distillation (MED). An absolute novelty is the generation of both, electric and thermal energy, in a ratio adjusted to the MED- system based on 100% renewables. Complete energy self-sufficiency, excellent suitability for isolated, off-grid operation and extremely high efficiency characterize the NEWSUN-concept. The goal of the project lies in the design and numerical evaluation of the entire process, as well as the empirical investigation of the Hybrid-Absorber providing electricity and heat. The latter represents a sophisticated combination of solar-thermal vacuum absorber tubes and Concentrator Photovoltaic Cells (CPV). Some advantages of this innovative technology are: - Exploiting the CPV cell’s heat loss as heat for the desalination process. - Use of highly efficient Multi-Junction Concentrator Cells. - Taking advantage of synergy effects of optical elements (i.e. mirrors, lenses) results in a significant cost reduction compared to the state of the art while at the same time increasing the overall efficiency to more than 70%. The technological challenges lie in the heat-sink design to ensure optimal operating temperature and long service life of the CPV cells. Furthermore, the analysis and optimization of the optical radiation distribution plays a critical role. After simulation of the entire system / process, the designed subsystem components will be investigated in detail in a laboratory environment and the results are used to validate the numerical models NEWSUN will enable Austria to become a technological leader in desalination and drinking water supply, an ever expanding global market with huge potential. Beyond that, distilled water can be supplied to local industries even in Austria, and the Hybrid-Absorber offers a great alternative to fossil fuels for any process where electricity and heat are needed.