Photovoltaic Reverse Osmosis Systems

    • For many remote off-grid communities, the lack of access to reliable electricity and clean water is a challenge for their economic development
    • Designing and implementing community owned and operated power generation alternatives and water systems is a step towards autonomy
    • Water purification systems powered by renewable energy need to be cost competitive in order to serve remote off-grid communities

    Challenges

    Location specific design requires skilled designers that is not available.

    Goal

    Design cost-effective, autonomous, robust, community-scale water purification systems powered by renewable energy

    Modular Design Methods for Photovoltaic Reverse Osmosis (PVRO) Systems

    Many water and energy systems are modular in nature.  This modular characteristic provides many advantages including the ability to tailor energy and water systems for individiual locations based on the local conditions and demands.  However, the modular nature of the systems means that there are many design choices that need to be made when configuring solutions for small communities.  Often, these design choices are beyond the abilities of the community and design tools which can aid in the design can greatly improve access to technologies.

    One example of a modular system that has been studied by members of the WERL is photovoltaic reverse osmosis (PVRO).  Designing a PVRO system is challenging due to the complex non-linear behavior of the system, the uncertainty in the energy source, and the enormous number of design choices that need to be made for even a small inventory. A designer with significant expertise is required to tailor a PVRO system for a given location, putting this technology out of reach of many communities. This research developed a modular design architecture to custom tailor PVRO systems from inventories of mass-produced modular components. To accommodate the large number of design choices, a hierarchical design method was developed, shown in Figure 1. The method uses a series of filters to limit the design space based on engineering principles and calculations. The system is then configured from the reduced design space using optimization methods and detailed system models. The design method also accounts for uncertainty in factors which affect the system performance, such as the solar radiation and water demand. A set of detailed physics-based system models were developed to enable this process. A novel method of representing a PVRO system using a graph was developed to enable rapid evaluation of different system configurations. This modeling technique was validated using an experimental PVRO system which was designed and constructed as part of this research.

    DesignProcess2

    Modular Design Methodology

    Development of Innovative Water and Energy System Concepts

    One of the research focuses of the WERL is the development of innovative concepts for water and energy systems.  These concepts include concentrators for solar thermal energy, energy recovery for small-scale reverse osmosis systems, and photovoltaic reverse osmosis systems.  Members of the WERL have recently developed a photovoltaic reverse osmosis system and deployed it in small, remote communities on the Yucatan Peninsula.  This system is tailored to meet the demands of an individual community and eliminate unnecessary components prone to failure, such as batteries.   This system was first tested in the laboratory and is seen in the video below.

    Experimental PVRO System