Field evaluation of a community scale solar powered water purification technology: A case study of a remote Mexican community application

Lack of clean water in small remote communities in the developing world is a major health problem. Water purification and desalination systems powered by solar energy, such as photovoltaic powered reverse osmosis systems (PVRO), are potential solutions to the clean water problems in these small communities. PVRO systems have been proposed for various locations. However, small PVRO systems with production on the order of 1 m3/day for remote communities present some unique technical, cost and operational problems. This paper reports on a project in which a PVRO system is designed, fabricated and deployed in remote village in the Yucatan Peninsula of Mexico. The community residents are indigenous people who are subsistence farmers and beekeepers. Technical and economic models used to configure the system for the community are presented. A plan is developed in cooperation with the community aimed at making the system self-sustaining in the long term. Methods and materials are developed to permit the community members to operate and maintain the system themselves. The results provide insights for the design and deployment of small community-scale PVRO systems in remote communities. © 2015 Elsevier B.V. All rights reserved.

The MIT PVRO system was successful at producing safe, quality drinking water in the remote village of La Mancalona, Mexico. TDS levels were reduced to acceptable levels (approximately 10 ppm) and biological contaminants were eliminated using the system's solar-powered UV disinfection. The system was able to work with both well water and collected rainwater, providing a reliable and flexible system to meet the community demands throughout both the wet and dry seasons. The local operators, themselves community members, have shown that they are able to operate and maintain the system. Economically, the system has proven viable as the community members are now purchasing the water at levels required for its long-term sustainability. However, operating a PV-powered water purification system using only cistern rainwater would permit it to be built without an RO element. Such a system would have pre-filters and the UV disinfection unit powered by relatively small solar panels. This would also require a change in the way that the village uses its water resources. Acknowledgments This fieldwork was financially supported by the W.K. Kellogg Foundation (Grant No. P3022694). We would also like to acknowledge the support of Omar Duayhe's team at the Fondo Para La Paz, who served as our on-site liaison to the communities and for their contributions in the deployment of the system in Mexico. The dry season extends from December through April with an average rainfall of 47 mm/month. During the remainder of the year (the wet season), the average is 152 mm/ month.