Inconvenience of equipment replacement in case of breakdowns Water pollution possibility Users credibility to the system System capacity limitations Operational inconvenience by different age-groups and gender Non-versatility (not adapted to other use, such as electricity, irrigation, etc. purpose) Time spend for fetching water Unwillingness to pay for water Land use Unfamiliarity of system Possibility of system abandoning due to the community's inability to pay for water Upland game birds Total Scores (0-5) 116 Glossary Airfoil-A blade or solid?, curved in such a way that it produces lift when placed in airflow. Alternating current (AC)-Electric current in which the direction of flow oscillates at frequent, regular intervals. Altitude-The angle between the horizon (a horizontal plane) and the sun, measured in degrees. Amorphous silicon-A thin-film PV silicon cell having no crystalline structure. Anemometer-An instrument for measuring wind speed, basically driven by drag forces of wind on small revolving cups. Annual equivalent life-cycle cost (ALCC) (annualized cost)-The equivalent annual cost of a project if the expenses are treated as being equal each year. Aquifer-A naturally occurring layer of water-bearing soil, rock, or sand. Array-A mechanically integrated configuration of PV modules and support structure designed to form a DC power-producing unit. Azimuth-Angle between true south and the point directly below the location of the sun, measured in degrees. Balance of system (BOS)-Components of a PV system other than the PV array. Battery-Two or more cells electrically connected for storing electrical energy. Battery bank-An energy storage capacity (ampere-hour). Borehole-A hole drilled through the ground to reach water. Borehole diameters vary depending on the required size of the system. Standard borehole sizes are 4-6 in. Capital cost-Initial investment of a project. Centrifugal pump-A pump that delivers water centrifugally using impellers by producing a pressure difference. Charge controller (battery charger)-A device that controls the charging rate and/or state of charge for batteries. Concentrator-An optical component of a PV array used to direct and increase the amount of incident sunlight on a solar cell. Conversion efficiency-The ratio of the electric energy produced by a PV/wind turbine to the energy from incident sunlight/wind. Crystalline silicon-A type of PV cell made from a single crystal or polycrystalline slice of silicon. 117 Current-The flow of electric charge in a conductor between two points having a difference in potential (voltage).

The availability of clean drinking water is a development issue faced by billions of people in the developing and near-developed world. Development organizations continually site the lack of access to clean water and sanitation as the leading cause of death amongst children in rural areas. The scale of this problem is immense, as are its solutions. The global nature of this issue opens the door for the application of communal solutions, as was demonstrated by the discussions surrounding the Johannesburg global climate meeting where water issues were a key concern that all nations could come together to support. Like energy, the need for clean water is increasing rapidly as supplies of traditional resources continue to diminish due to overuse, waste, and pollution. Unlike energy, the ability to harness local resources to produce water is not possible. However, we do have the capability to use local energy resources to gain access to water supplies that would otherwise be unavailable and then ensure that this water is safe for human consumption. Most water is located underground in deep aquifers, in surface lakes, rivers, and streams or in the ocean. Technologies exist to make use of all of these water sources but in many cases, the absence of available, inexpensive energy makes their use expensive, time consuming, and potentially dangerous. The proper application of any number of energy options available today can make gaining access to this water a reality in many areas not previously considered. This report, one of three written by the author, provides insight into providing water to people in rural areas. By considering all aspects of water systems from assessing availability, accessibility, treatment, supply systems, and post use treatment, this document provides insight into all aspects of the water system. The document also discusses a variety of energy sources available to rural and remote areas to provide power for any proposed water systems. The report is unique as it provides a very evenhanded approach to the selection of different technologies and power choices. The purpose of this document is to provide insight into the different options that are available and methods to understand which technology may be the best for specific needs, conditions, and locations. We also hope to dispel some of the misconceptions about appropriate or inappropriate technologies through the publication of this document. Because the access to clean water is such a large and encompassing issue, all solutions have their place. The difficulty is determining which technologies are most appropriate for each user's specific need. This book is one in a series of guidebooks that NREL produced, with the support of the U.S. Department of Energy, to couple commercial renewable energy systems with rural applications, including other water issues, rural schools, health posts, and micro-enterprise. Other water related publications in this series describe the technical aspects of water pumping technology and provide insight to issues of wat...