Solar power-run RO plants quench thirst for safe drinking water

At the tip of an unused railway line is the Bela Rail Wheel Factory, a landmark in the Saran district of Bihar. Deeper in the area, an auto rickshaw blares out, “Balu makhi ko bhagana hai, kala-azar mitana hai (Shoo away female sandfly, end kala-azar)”.

Spread of disease because of unclean surroundings and contaminated water and food is not uncommon in many rural areas of Bihar. Mahmadpur, a village only 34 km away from state capital Patna, where the auto rickshaw was carrying out an awareness campaign about the fly that carries the parasite of life-threatening kala-azar disease, is no different.

According to the National Health Profile, Bihar accounts for most kala-azar cases: 72 per cent of 5,758 reported cases in the country in 2017. In the same year, Bihar also reported 309,289 cases of acute diarrhoeal diseases and 171,233 of typhoid — two water-borne ailments.

At the Derni Bazar area near Mahmadpur sits Krishna Rai, a compounder who runs a clinic. He treats patients for minor ailment but refers them to the district hospital for everything else. “I sometimes give them medicines and injections, too,” he said

Villages in these remote areas are dependent on hand pumps for drinking water, with hardly any government piped water supply. This offers a lucrative catchment area for reverse osmosis (RO)-based water treatment plants.

At Derni and Bheldi villages, TARAurja, an enterprise of Development Alternatives funded by Smart Power India, an initiative of the Rockefeller Foundation, and DESI Power operate solar power mini grids, along with water treatment plants.

These RO plants serve two objectives. They provide an anchor load for the solar power plants especially during summers when water chilling facility is also used besides bundling up related businesses with power generation. Smart Power’s rural development programme has 25 water-treatment units. These have touched lives of 5,000 people, it claims.

Two of these plants are run by energy-supply companies, while the rest are run by local enterprises. Each water-treatment unit serves at least 100-120 households or shops giving access to safe drinking water.

At Bheldi, one cycle producing 1,000 l of RO water uses 6 Kw of power, which includes chilling that is not required in winters. The RO jar is sold under TARAurja brand.

The Bheldi plant inside the same compound as the 37.5-Kw solar power plant has been set up in partnership with Pirmal’s Sarvajal initiative.

According to Smart Power, households form 20 per cent of the customer base but it is cold water more than clean drinking water which is a greater driver for the households. Micro enterprises from the surrounding areas and neighbouring villages form the remaining 40 per cent clientele. Demand, in fact, reduces to one-third during non-summer months stretching the breakeven for the plants to 16 months. A plant costs around Rs 8-9 lakh.

Towards the north of the state, at Chakai in Araria district, water is not a scarce resource and hand pumps dug 20-40 feet yield enough though the water may not be fit for drinking.

DESI Power runs a water-treatment plant here in partnership with SR Acqua. The plant earns around Rs 40,000 every month during summers. A 20-litre jar is sold for Rs 25 and there are about 200 customers for such water.

Together with drinking water, these ESCOs are supplying irrigation water through water bore pumps that are powered with solar electricity.

At Chakai, irrigation water is piped while DESI puts the water in a drain running through nearby fields in Baharbadi village. It charges Rs 100 for an hour of supply. DESI has employed Bhalo Devi to run a bio mass and solar hybrid power plant at Baharbadi from where she also controls the irrigation pum.

“In the sowing season, she is a busy person, keeping track of how long water has been released while checking on power load as well,” said S N Sharan, managing director, DESI Power.

For his ESCO, water supply is an integral part of the business model especially in times when it faces competition from cheap grid power supply.