Carlsberg Group is deploying a novel solar technology to power a sustainable clean water initiative in India’s West Bengal. The innovative partnership will see a water-stressed town of 4,000 people provided with clean drinking water.
Novel renewables tech driving water supply
With the brewing giant partnering with Desolenator and its technology, the plan will see a novel solar thermal and photovoltaic hybrid system generate clean water for the Sundarbans region in West Bengal.
The region has been affected by climate change and a severe hurricane this year which have reduced water supplies to the extent that water has had to be trucked in to some areas to meet the population’s needs.
Due for completion in mid-2021, the sustainable water purification technology will create some 20,000 litres of clean drinking water a day.
Partnering with Desolenator forms part of the brewer’s ‘Together Towards ZERO’ sustainability programme that aims to eliminate water waste across its breweries by 2030 and to protect shared water resources in high-risk areas.
The Sundarbans is around 120 km from Carlsberg’s Kolkata brewery, and has been identified as an at-risk area for water by WWF’s Water Risk Filter which has been deployed by the Danish company. Indeed, Carlsberg has noted that all of its Indian breweries are in high-risk areas.
In the South 24 Pargana’s district, high levels of salinity make the water unfit for human consumption while the ebb and flow of river water leads to large daily variations in salinity levels.
This makes purification using conventional methods more challenging. Desolenator’s system is 100 per cent solar-powered to create high-quality water from the most complex sources.
Community-led distribution model
A community-led distribution model is being designed to support effective access for the 4.7 million people who live in the Sundarbans.
Working through a multidisciplinary partnership, the plan will use local expertise from WaterAid and the Sundarbans Social Development Centre as well research from the UK’s Strathclyde University and grant support from the Netherlands Enterprise Agency.
“By empowering the community, this appoach is expected to enable the long-term supply of clean drinking water.”
The distribution model will create employment for female micro-entrepreneurs, and will be tailored to the lives and needs of the people of South 24 Pargana’s district.
The social enterprise model will see subsidised water sold with profits being ploughed back into the enterprise. By empowering the community, this approach is expected to enable the long-term supply of clean drinking water.
“Reliance on solar energy makes this an attractive and sustainable option. Success, not just of the technology but community-based management of the infrastructure could inspire expansion into other flood-prone areas with a similar challenge with regard to water quality,” said As VK Madhavan, chief executive of WaterAid India.
Low-carbon water purification technology
Desolenator’s technology relies on the multi-effect distillation (MED) process in which multiple distillation stages are fed by preceding stages but at lower temperatures and pressures.
This makes the process highly efficient. Furthermore, in their combined solar thermal and PV hybrid, water is used to cool the PV process, making it more efficient too. Desolenator claims that the combined process raises solar energy conversion efficiency from around 15 per cent to more like 60 per cent.
The PVT array heats up cold water before it is fed into a flash-tank to produce steam which drives the MED process. According to the company, there is a built-in process to remineralise the water produced to make it suitable for drinking or for any business-specific application.
The patented modular design – each produces some 250 m3/day – enables flexibility in deployment and ease of adding capacity while distilling complex water types into high-quality product water.
Power from the PV array is used for system electrical by control system, pumps, sensors and the like, Any excess electricity from the solar array is stored in batteries while excess thermal energy is stored in hot water tanks fitted with a thermal battery. This allows a continuous supply of energy, even during the hours of darkness.
“Desolenator argues its approach is a sustainable option for other arid and coastal areas where rising sea levels and more frequent storms are making groundwater saline."
As an off-grid solution requiring no filters or membranes, minimal batteries and a claimed 95 per cent reduction in chemical use, Desolenator argues its approach is a sustainable option for other arid and coastal areas where rising sea levels and more frequent storms are making groundwater saline.
“India is already experiencing the global water crisis. This collaboration has huge potential both in creating a sustainable solution to the crisis and at the same time providing the opportunity to engage women from the local community to lead and manage the distribution of this precious resource,” added Rishi Chawla, VP, corporate affairs, Carlsberg India.
