Development of a novel atmospheric pressure plasma system for the reduction of water use in the cleaning of mirrors in Concentrating Solar Power plant

Lead Research Organisation: CRANFIELD UNIVERSITY
Department Name: School of Water, Energy and Environment

Abstract

The focus of this project is to understand the utilisation of plasma-assisted surface conditioning of low-iron glass solar reflecting mirrors for concentrating solar thermal power applications.
The Global Concentrating Solar Power (CSP) market was valued at over $3 Billion US in 2016 and is anticipated to grow by 13% by 2025. CSP plants generate electricity by concentrating sun light with large arrays of mirrors which are usually located in desert regions. Consequently, the mirrors get covered in sand and dust, and require cleaning with brushes and water on a regular basis. Currently much water is used to clean the mirrors, a precious resource in arid terrains. The aim of this project is to investigate the characteristics of a novel atmospheric pressure plasma system used to condition CSP concentrating mirrors which will be capable of reducing the amount of water used in the cleaning process.
There is also a compelling business desire to undertake this project. The development of a novel atmospheric pressure plasma system will be a significant game changer in the CSP market. Such a disruptive technology is anticipated to yield significant commercial benefits.
The project will include the following stages within the overall research methodology:
Modeling and simulation of the deposition of sand and dust onto mirror surfaces at a variety of different geographical locations
Experimental analysis of sand and dust saltation, erosion, abrasion, and suspension in arid regions within the solar belt (typically within the tropical latitudes).
Characterisation of mirror surfaces by interferometry, scanning electron microscopy with energy dispersive x-ray analysis for elemental compositional identification, photogrammetry for shape distortion, reflectometry for specular reflectance, and contact angle measurements to determine surface condition.
Investigation of the characteristics to improve the efficiency of a novel atmospheric pressure plasma system for the in situ surface cleaning of mirror surfaces in the presence of water in arid regions.
Testing and optimisation of the plasma system for a range of mirror surface types at different CSP locations within the solar belt or at representative test locations within Europe.

Planned Impact

The major beneficiaries of the research outputs from the Centre for Doctoral Training in Ultra Precision (CDT-UP) include UK manufacturing companies (especially SMEs), the University partners, including the two primary universities, and the wider UK universities engaged in Ultra Precision research, in addition to society in general. Benefits will be realised in terms of:- increased economic activity in the field of UP through spin-out companies, licensed technology outputs, and the realisation of new products made possible with the application of UP manufacturing capabilities; greater knowledge of and a wider appreciation of the technical capabilities of UP systems; the provision of highly trained PhD level personnel for UK industry to spearhead new ultra precision competencies; and the creation of new products for the market based on UP competencies and technologies, which have the potential for significant societal impacts in areas such as health-care, transport, energy generation, and communications.
The importance of ultra precision manufacturing to the UK economy and the key issues and barriers to economic success are highlighted in the main proposal which demonstrate the central role of ultra precision manufacturing technology in ensuring economic growth. Many emerging sectors and next generation products will demand ultra precise components (nanometre, and sub-micron-level tolerance). To date semiconductor systems, and microsystems (optical, mechanical, or electrical) use complex expensive process steps in their production. Such extensive process chains are needed to create even initial pre-production prototypes. This issue has become a significant barrier to SME's realising their innovative products requiring UP. We aim to develop ultra precision manufacturing technologies that will offer precision capabilities, with a reduced level of capital investment compared to traditional semiconductor fabrication routes. These include:- wide area roll-to-roll printing of electronic devices, optical films, and structured surfaces; novel micro machining technologies for the production of 3-dmensional components such as micro-mechanical elements, embossing and injection mould tools, and micro-embossing tools.; direct writing and accretion of nanoscale features of semiconductor materials for low cost prototyping of micro and nano systems.
Manufacturing success requires not only the generation of new knowledge, it also requires people with the ability to invent and innovate. The education and research training of the CDT-UP will be developed in partnership with the new EPSRC centre for Ultra Precision, a wide range of industrial collaborators, and other UK universities working in the field of UP. This leading educational centre will respond to both the industrial need of UK companies, and the educational development strategies of UK universities, in developing the people with the technical capabilities necessary to move from the inventive steps to innovation platforms, thereby increasing the potential for wealth creation in the UK. We ensure that UK manufacturing can meet the future technical and business challenges needed to compete globally. The potential of the UK's innovation capacity to create new high-end manufacturing jobs is significant. Maximising this wealth generation opportunity within the UK will however depend on successfully realising next generation innovative production systems. Without relevant production research, r&d infrastructure, and an effective technology supply chain, there will be a limit to the UK's direct employment growth from its innovation capacity, leading to a constant migration of UK wealth creation potential into overseas economies. CDT-UP will develop a significant number of highly trained manufacturing engineers who will be essential to provide the leadership necessary to drive UK high value manufacturing forward and provide the vision for future prosperity.

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