Using municipal wastewater in Indian power plants is part of the solution

India is a water-stressed country. Water shortages and regional droughts have forced several coal fired power plants to shut down due to a lack of water – the 2100 MW Farakka power plant in West Bengal was one plant that had to shut down this year. These closures have lost companies, including the power generating companies, significant potential revenue. Partly as a result of the lack of water, the Indian Government made it mandatory in January 2016 for power plants within a 50 km radius of sewage treatment plants to use the treated wastewater. Municipal wastewater was already being successfully utilised in a few Indian power plants.

An article reports on the findings of a recent Greenpeace report, Pipe dreams: treated sewage will not solve coal power’s water problems on the availability of municipal wastewater for Indian coal-fired power plants. However, it is not surprising that only some of the coal power plants can make use of this non-fresh water source. According to Greenpeace, just 8% of the power plants can completely switch to municipal wastewater, and an additional 5% can partially meet their water requirements from this source – these are plants located within 50 km of the wastewater source.

This is to be expected since the majority of the power plants are not located near the towns with the municipal water treatment plants – instead, they are located near coal mines or in other areas. In addition, not all of these coal-fired power plants are in water-stressed areas. Using municipal wastewater in the 13% of power plants still saves a significant amount of fresh water – according to Greenpeace about 2525 ML a day (assuming water demand is 3.5 m3/MWh). The economics of using this water source does depend on the cost of its transport and treatment; the wastewater must be treated before it can be used in recirculating cooling systems (cooling towers). Building the required transport network and modifications to the water treatment plant at the power station could be expensive.

However, the Government is actually allowing the associated cost of using municipal wastewater to be passed on to the consumer, according to its power tariff policy announced in January 2016. The Government has also introduced water efficiency regulations, limiting the amount of water consumption at existing power plants to 3.5 m3/MWh and for new power plants at 2.5 m3/MWh. The regulation was announced in December 2015, and came into effect on 1 January 2017. Despite the cost, it would still save a considerable amount of freshwater. Shouldn’t saving water still be a priority? Municipal wastewater is already providing an economic solution for many power plants around the world, and is surely a viable solution for Indian power plants to reduce their reliance on freshwater.

Water usage in India, and not just for power plants, has certainly moved up the political agenda.