Rainwater can help meet AI’s water needs

Rainwater can help meet AI’s water needs

Justin Talbot Zorn & Bettina Warburg

In late September, Microsoft announced that it has reached an agreement to reopen the Three Mile Island nuclear power plant to power its growing network of data centers. Reviving the plant, which partially collapsed in 1979, is one of several extraordinary steps tech companies are taking to meet the growing energy needs of artificial intelligence, cloud computing and other technologies. Industry analysts at Transforma Insights predict what the world will achieve almost 30 billion IoT devices by 2030 — compared to less than 10 billion in 2020.

Still, as big tech companies tout nuclear power and other low-carbon energy plans, they have presented surprisingly few ideas to meet their rapidly growing use of another scarce resource: water.

Data centers require vast amounts of water for liquid cooling systems to absorb and dissipate the heat generated by servers. Researchers at the University of California, Riverside found that between 5 and 50 ChatGPT requests can consume up to 500 milliliters of water (about the amount in a 16-ounce bottle). These sips are stacked. Google is used 20 percent more water in 2022 compared to 2021 because he accelerated AI development. Microsoft’s water consumption increased by 34 percent over the same period. According to forecasts, by 2027, the amount of water that artificial intelligence uses in one year worldwide will be equal to the small European nation consumes. Worse, the large number of data centers situated in regions with a shortage of water. Recently, Google’s data center in The Dulles, Oregon managed a third of the city’s water supply in drought conditions.

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While some technology companies are investing in water recycling, others are envisioning the future innovations such as transporting seawater inland or even moving data centers under the ocean. Many simply ignore how much water use can end up costing, not to mention the specter of drought. To date, only a handful of technology companies have taken steps to implement perhaps the simplest, most proven, and most promising water risk mitigation strategy: harvesting rainwater from the sky.

People collected rainwater since ancient times. Now there is growing interest among supporters of water conservation, collecting rain from roofs and channeling it through gutters into tanks. Then, in the data centers, this water will pass through the cooling systems. The last ones teaching show that collecting even a small portion Rain that falls in an area can eliminate water shortages while replenishing groundwater and reducing pollution from stormwater runoff. There is no need for a utility intermediary when water is collected from the roof, which means that harvesting rainwater can be cheaper than purchasing an equivalent amount from the municipal water supply, and avoid greenhouse emissions associated with pumping water between areas.

Over the years, some states and municipalities have restricted residential and industrial rainwater harvesting due to water quality concerns or reduced water supplies. But very recently state after state allowed practice as evidence of conservation benefits is growing. Cities like Tucson and Austin now encourage rainwater harvesting by offering incentives and setting requirements. Apple, Ford and Toyota recently integrated rainwater harvesting systems into corporate campuses and manufacturing facilities.

But we believe data centers are the biggest untapped opportunity for water conservation through rainwater harvesting. It’s not just that data centers have an urgent need for water, but also that their large, flat roofs are well-suited to collecting water. A 50,000 square foot rooftop can collect approximately 31,000 gallons of water from one inch of rain—about as much as fills an average residential swimming pool. Many data centers have rooftops of more than 100,000 square feet, and some hyperscale data centers owned by large technology companies measure up to a million square feet.

Why don’t more data centers rely on rainwater harvesting? Cost, for example. Setting up a system for a commercial facility, such as a data center, typically costs between $2 and $5 per square foot, depending on the complexity of the system, storage and filtering needs. If the cost of municipal water supply in the region is low, it may not make sense to invest in rainwater harvesting. Moreover, rainwater systems rarely cover the total amount of water needed to cool a data center. Some massive structures can use a million gallons of water every day.

But the economics of rainwater harvesting are becoming increasingly logical as both the cost and uncertainty of water resources increase, especially with climate change. Like installing solar panels, installing a rainwater harvesting system is a one-time investment that reduces long-term utility costs. In some cases, companies can use their existing stormwater management budgets to collect rainwater. In places like the greater Dallas area, home to many of the nation’s data centers, average rainfall means rainwater harvesting systems can cover up to a third of data center cooling needs—depending on size and storage systems. Although these numbers are lower in arid regions, the higher cost of water in these areas usually makes the economics of rainwater harvesting more attractive. As public concern grows about the environmental impact of artificial intelligence and other technologies, companies will likely need to consider both the financial and reputational risks of inaction on water.

Some industry leaders are beginning to see the potential. AND Google data center in South Carolina uses ponds to collect rainwater. AND Microsoft Data center has introduced rainwater harvesting in Sweden, reducing dependence on local water sources. Amazon Web Services highlights the potential rainwater collection in its water-positive strategy.

At the policy level, green shores—Clean-energy-focused financial institutions that are expanding across the country following a $27 billion federal investment through the Inflation Reduction Act could soon begin helping finance stormwater projects. Rainwater could win bipartisan support and perhaps even tax breaks under recent renewable energy legislation. While this approach may be popular with Democrats because of its resistance to climate change, Republicans may support rainwater harvesting without having to accept the science of climate change or oppose the fossil fuel lobby.

At a time when Silicon Valley is turning to energy solutions like long-dormant nuclear plants, it may seem strange to tackle a pressing global problem with a technology as old as civilization itself. But sometimes the best decisions can fall from the sky.

This is an analytical article and the views expressed by the author(s) are not necessarily those of the author(s). Scientific American.