This paper justifies photovoltaic (PV)-powered electrodialysis (ED) as an energy and cost-effective means of desalinating groundwater in rural India and presents the design requirements for a village-level system. Saline groundwater, which underlies 60% of India, can negatively impact health as well as cause a water source to be discarded because of its taste. A quarter of India's population live in villages of 2000-5000 people, many of which do not have reliable access to electricity. Most village-scale, on-grid desalination plants use reverse osmosis (RO), which is economically unviable in off-grid locations. Technical and ethnographic factors are used to develop an argument for PV-ED for rural locations, including: system capacity, biological and chemical contaminant removal; water aesthetics; recovery ratio; energy source; economics of water provision; maintenance; and the energetic and cost considerations of available technologies. Within the salinity range of groundwater in India, ED requires less specific energy than RO (75% less at 1000. mg/L and 30% less at 3000. mg/L). At 2000. mg/L, this energetic scaling translates to a 50% lower PV power system cost for ED versus RO. PV-ED has the potential to greatly expand the reach of desalination units for rural India.
Bibliographical noteFunding Information:
The authors would like to thank the Tata Center for Technology and Design at MIT , Jain Irrigation Systems Ltd. , and the MIT UROP program for funding the research reported in this paper. Additionally, the authors would like to thank Georgia Van de Zande for her assistance in completing field research in India .
- Brackish groundwater
- Photovoltaic energy