It\u2019s the little-known challenge being faced by solar projects in India. Keeping solar panels up and running requires cleaning them every fortnight, water for which many developers are finding hard to procure. It is not a coincidence here that most solar plants are located in arid areas. With solar developers having compromised on their margins by quoting low tariffs to bag projects, the rising costs of water threaten to further hurt the profitability of several projects. Some solar developers in Rajasthan have seen water costs almost doubling in 3-4 years. In Karnataka, tariff for industrial water usage was hiked by 100 times in 2018. Significantly, cleaning costs can comprise 25-35% of the operational and maintenance costs of a plant. According to a study by Bridge to India, a renewable energy research firm, about 60% of the water used for solar panels is procured through bore-wells. For plants which use surface water, the annual cleaning cost can be as high as Rs 1 lakh for every MW of installed capacity. The study recorded \u2018very high\u2019 water consumption at plants in Rajasthan, UP, Gujarat, Punjab and Haryana, where a quarter of India\u2019s installed capacity is located. Tamil Nadu (TN), Karnataka and MP \u2014 with 38% of solar plants\u2014have \u2018high\u2019 water consumption levels. Many developers are reportedly resorting to illegal means to procure water. \u201cTo promote solar power, a number of environmental checks and balances are waived and there is often no cap on the water that can be used to clean panels,\u201d Vinay Rustagi, MD of Bridge to India, tells FE. \u201cThis is also leading to illegal water extraction at a number of places,\u201d he says. \u201cIn the push for installation, the issue of water usage was not a priority for policymakers,\u201d an industry veteran says. \u201cThere is no specification on the means of sourcing water in auction documents and parks owned by big companies often outsource panel-cleaning tasks to contractors who exploit the situation,\u201d he says \u2014 villagers in TN\u2019s Kamuthi taluk protesting over an Adani park\u2019s water consumption was a fallout of this phenomenon. At the same time, there are states that have relied on additional channels to meet such needs. \u201cAs a part of development of solar parks in Madhya Pradesh, a detailed study of the catchment and drainage pattern is conducted,\u201d says Manu Srivastava, principal secretary, new and renewable energy, MP. \u201cThe purpose is to identify places from where water can be impounded and used for a solar park,\u201d he points out. Shashi Shekhar, vice-chairman, ACME Group, says that to cut panel-cleaning costs, his company has installed robots with soft linen brushes at its solar parks in Rajasthan's Bhadla and Madhya Pradesh's Rewa. Agreeing that water availability is becoming a concern, he says, \u201cthere is a plan for setting up a 500-km water pipeline from a desalination plant in Gujarat's Bhuj to Rajasthan.\u201d Given that solar capacity stands at 23 GW at present, as against the target of 100 GW by 2022, the challenge faced by solar plants on account of water shortage is only likely to intensify over time, necessitating a coherent policy on the issue.