Abstract
About 2.1 billion people still lack safely managed drinking water, and in India falling groundwater and contamination add local pressure. This article reviews the evidence from WHO/UNICEF, NITI Aayog and the Central Ground Water Board, then examines the options: conservation, treatment, reuse and atmospheric water generation (AWG). It finds that AWG is a technically valid but energy-intensive supplement for drinking water, best suited to places where other safe sources are unreliable, and not a replacement for water management.
1. Introduction
Safe water is the foundation of public health, and the world is off track to deliver it to everyone. The WHO/UNICEF Joint Monitoring Programme reports that in 2024, 1 in 4 people, or 2.1 billion, still lacked safely managed drinking water, and 106 million drank directly from untreated surface sources. The same report concludes that universal safely managed coverage “appears increasingly out of reach” by 2030.
India is part of this picture. The NITI Aayog Composite Water Management Index (2018) stated that 600 million Indians face high to extreme water stress, that about two lakh people die every year from inadequate access to safe water, and that national water demand is projected to be twice the available supply by 2030, with an eventual loss of about 6% of GDP. These are NITI Aayog’s own projections from 2018, and they remain a useful statement of the scale of the problem.
2. Global and local challenges
Unequal access. People in least developed countries are more than twice as likely to lack basic water and sanitation services, and in fragile contexts safely managed drinking water coverage is 38 percentage points lower than elsewhere (WHO/UNICEF, 2025). Between 2015 and 2024 rural drinking-water coverage improved from 50% to 60%, while urban progress stagnated.
Groundwater pressure in India. Groundwater is the main buffer against dry seasons, so how much is drawn matters. In the 2024 national assessment (summary at GKToday, based on the Central Ground Water Board report), India’s annual recharge was 446.90 billion cubic metres (BCM), extractable resource 406.19 BCM and annual extraction 245.64 BCM, a national stage of extraction of 60.47%. The average hides local stress: of 6,746 assessment units, 751 (11.1%) were over-exploited and 206 (3.05%) critical. The share of safe units has improved from 62.6% in 2017 to 73.4%.
Quality as well as quantity. Water that exists may still be unsafe. The JMP definition of “safely managed” requires water that is available when needed and free from faecal and priority chemical contamination, so contaminated supply counts as a gap even when a tap is present.
3. Solutions: a portfolio, not a single fix
No single technology closes the gap, and the evidence points to combining measures:
- Demand management and conservation (efficient irrigation, leak reduction) addresses the largest uses first.
- Recharge and reuse (rainwater harvesting, treated wastewater) protects the aquifer buffer described above.
- Treatment at the point of use (filtration, UV, reverse osmosis) fixes quality where a source exists but is contaminated.
- Alternative sources such as atmospheric water generation supply drinking water where reliable sources do not exist, are far away or are contaminated.
The choice depends on local conditions, cost and who runs the system, which is why the next section looks at what AWG can and cannot do.
4. Atmospheric water generators: principle, performance and limits
Principle. Air always contains water vapour. An AWG either cools air below its dew point so vapour condenses, or uses a desiccant material that absorbs vapour and then releases it as liquid when heated. The water is then filtered and mineralised for drinking.
Energy performance. A peer-reviewed comparison by Peeters et al. (2020), Environmental Science: Water Research & Technology reports specific yields of 1–4 litres per kWh for air-cooling condensation systems and 0.1–1 litre per kWh for desiccant absorption/desorption cycles. In per-litre terms, that is roughly 0.25–1 kWh per litre for condensation and 1–10 kWh per litre for desiccants (our conversion of the paper’s figures). The authors note that cooling-based systems are strongly dependent on atmospheric conditions, and that atmospheric water harvesting needs more than a hundred times the energy of seawater desalination.
What this means in practice.
- Output rises and falls with temperature and humidity, so rated capacity should be read with the test conditions.
- Electricity is the main running cost, so the best sites have dependable power, and ideally solar.
- AWG suits drinking and cooking water, not bulk uses such as irrigation.
Where VayuJal fits. VayuJal’s units are designed from 43 to 3,500 litres per day per unit, with multi-unit installations above 50,000 litres per day, and the company states drinking water quality aligned with IS 10500:2012. Company-reported figures are separate from the peer-reviewed evidence above and should be read as such.
5. Conclusion and key takeaways
Water scarcity is both a supply and a quality problem, and the data show it is unevenly spread. Groundwater at the national level is moderately used (60.47%), yet hundreds of local units are over-exploited. Atmospheric water generation can safely supplement drinking-water supply where other sources fail, provided its energy needs and climate dependence are planned for.
- 2.1 billion people lacked safely managed drinking water in 2024.
- India’s 2018 NITI Aayog assessment projected demand twice supply by 2030.
- AWG yields 0.1–4 litres per kWh depending on the method, so power source and climate decide viability.
- Use AWG for drinking water, alongside conservation, recharge and treatment.
References
- WHO and UNICEF (26 Aug 2025). 1 in 4 people globally still lack access to safe drinking water. Joint Monitoring Programme report on household drinking water, sanitation and hygiene 2000–2024.
- NITI Aayog (June 2018). Composite Water Management Index. Government of India.
- Central Ground Water Board / Ministry of Jal Shakti (2024). Dynamic Ground Water Resource Assessment, as summarised by GKToday.
- Peeters, R., Vanderschaeghe, H., Rongé, J., Martens, J.A. (2020). Energy performance and climate dependency of technologies for fresh water production from atmospheric water vapour. Environmental Science: Water Research & Technology.
- Alsaqoor, S. et al. (2024). Atmospheric Water Harvesting Technology: Review and Future Prospects. Journal of Ecological Engineering 25(3):291–302.
Figures verified on 7 October 2026 from the pages linked above. Reference 3 is a secondary summary of the CGWB report.
