Water scarcity is a growing concern in today’s world, with more than 3 billion people around the planet already living in water-stressed countries. Moreover, as the global population continues to expand and urbanization accelerates, the demand for clean water is rising rapidly.
Consequently, the need for innovative water technologies is becoming more urgent than ever, particularly in water-stressed countries where crop failure and famine are looming threats. Hence, as we have alluded to previously, technologically mature solutions such as reverse osmosis desalination are gaining traction to quench the growing global thirst for clean water.
Nevertheless, meeting this need and achieving the UN’s main Sustainable Development Goal 6 (SDG 6), ensuring the availability and sustainable water management for all by 2030, is likely to require a much greater deal of affordable innovative solutions and investments.
An emerging area that is gradually drawing policymakers and investors’ interest is precipitation enhancement technologies (artificial rain), which refer to methods used to increase rainfall in areas with low precipitation to mitigate the effects of drought conditions.
While cloud seeding and atmospheric water generators (AWGs) are currently the most widely used technologies to increase precipitation in water-scarce areas, researchers are exploring other methods, such as atmospheric ionization, as potential ways to induce rainfall.
Cloud seeding is a process that involves releasing substances such as silver iodide, sodium chloride, and dry ice (frozen CO2 gas) into the air to promote the formation of ice crystals and rain droplets, which subsequently lead to the formation of rain.
After it was initially experimented by scientists at the General Electric Research Lab in the 1940s, various countries have adopted it for several decades now. For example, in the Emirates, the National Centre of Meteorology has been using planes and drones to release rain-inducing substances into the atmosphere for decades. Similarly, the Beijing Weather Modification Office in China has been generating billions of cubic meters of rainfall since the 1950s using this technique.
While cloud seeding seems to be a cheap alternative relative to other clean water production strategies like desalination, determining its true comparative effectiveness/cost has historically proved challenging. Meanwhile, in terms of effectiveness, recent statistical research has indicated that cloud seeding activities have the potential to increase precipitation by up to 15-20%, which could benefit companies like privately held Ice Crystal Engineering or Weather Modification.
The identification of this potential has in turn caused over a dozen firms, research institutions, and individuals to patent nearly twenty cloud seeding technologies or methods since 2018. Moreover, new approaches, such as the use of nanotechnology and artificial intelligence, are being explored to improve the efficacy and economic efficiency of cloud seeding techniques.
Another approach to boost precipitation involves the use of AWGs. These machines work by cooling the air to the extent that water condenses on their surfaces – a comparable process to what household dehumidifiers utilize for extracting moisture from the air.
AWGs are particularly useful in regions with high humidity and low rainfall, such as coastal areas. These machines, such as the ones produced by Israeli-based Watergen (privately held), have the advantage of being able to produce water without any infrastructure, making them particularly suitable for remote areas. AWGs come in various sizes, starting from small units for personal use that can generate 1 to 20 liters of water per day, to larger commercial-scale units that can yield 1,000 to more than 10,000 liters per day. Despite the fact that AWGs require running condenser and fan systems that can consume considerable amounts of energy, the energy/water ratio has been greatly enhanced in the last few years by technological improvements. While AWG systems can provide a comparably more reliable and consistent source of water than cloud seeding, they require a significant investment upfront, making them less affordable to many communities and regions.
Yet another technology to produce artificial rain makes use of lasers to stimulate cloud formation. The technology, known as “laser cloud seeding,” uses lasers to make air molecules in the atmosphere electrically charged (ionization). This creates particles that facilitate water droplets to form into clouds, which then can produce rain. The method works similarly to cloud seeding but triggers a natural process that promotes cloud formation rather than introducing particles into the atmosphere.
Nevertheless, while laser cloud seeding technology has shown promise in increasing rainfall in arid regions, it has not been widely developed due to concerns about cost-effectiveness, environmental impacts (including potential release of harmful gases like ozone and nitrogen oxides), and the need for further research.
In contrast, Swiss-based WeatherTec (privately held) as well as other promising companies, are developing innovative technologies that can initiate and enhance rainfall in semi-arid regions by mimicking the natural ionization process of the sun. These techniques are completely environmentally friendly, produce negative ions without leaving behind any waste products/harmful gases and could prove extremely affordable, being as much as twenty times cheaper than desalination technologies.
In conclusion, the precipitation enhancement technology sector looks to hold a significant potential with an estimated addressable market of $45 billion. As such, it could soon draw investors’ attention and some companies are already getting ready to capitalize on this potential trend by going public, such as Rain Enhancement Technologies which is in the process of merging with a SPAC (dMY Technology Group VI). Nevertheless, we reckon that the field is still relatively nascent and further development is needed to fully unlock the potential of emerging technologies which, for most, are still in trial mode.