A single Bitcoin transaction could use as much water as a backyard swimming pool

Cryptocurrency mining uses a significant amount of water amid the global water crisis, and its demand for water may grow even more. in a comment published November 29 in the magazine. Cell Report Sustainability, financial economist Alex de Vries provides the first comprehensive estimate of Bitcoin’s water usage. He warns that its enormous scale could affect drinking water if it continues to operate unrestricted, especially in countries already struggling with water shortages, including the United States.

“Many parts of the world are experiencing droughts and freshwater is becoming an (increasingly) scarce resource,” says de Vries, Ph.D. Student at the Vrije Universiteit Amsterdam. “If we continue to use this valuable resource to perform useless calculations, I think the reality will be really painful.”

Previous research on the resource use of cryptocurrencies has primarily focused on electricity consumption. By mining Bitcoins, the most popular cryptocurrency, miners around the world essentially compete to solve mathematical equations on the Internet, with the winners getting a share of Bitcoin’s value. On the Bitcoin network, miners make about 350 quintillion (that is, 350 followed by 18 zeros) guesses every second of the day, an activity that consumes an enormous amount of computing power.

“The correct answer emerges every 10 minutes, and the rest of the data, quintillions of them, are calculations that are of no further use and are therefore immediately discarded,” says de Vries.

During the same process, a large amount of water is used to cool computers in large data centers. Based on data from previous research, de Vries estimates that Bitcoin mining consumes between 8.6 and 35.1 gigalitres (GL) of water per year in the US.

In addition to cooling computers, the coal- and gas-fired power plants that provide electricity to run computers also use water to lower the temperature. This cooling water evaporates and is not available for reuse. Evaporated water from hydroelectric plants also increases the water footprint of Bitcoin’s energy demand.

In total, de Vries estimates that in 2021, Bitcoin mining consumed more than 1,600 GL of water worldwide. Each transaction on the Bitcoin blockchain uses 16,000 liters of water on average, about 6.2 million times more than using a credit card, or enough to fill a backyard swimming pool. Bitcoin water consumption expected to rise to 2,300 GL in 2023, says de Vries,

In the US, Bitcoin mining consumes between 93 GL and 120 GL of water each year, which is equivalent to the average water consumption of 300,000 US households or a city like Washington, DC.

“The price of Bitcoin has just increased recently and reached its highest point of the year, despite the recent collapse of several cryptocurrency platforms. This will have serious consequences, because the higher the price, the greater the environmental impact,” he says. Vries.

“The most painful thing about cryptocurrency mining is that it uses so much computing power and so many resources, but these resources are not used to create some kind of model, like artificial intelligence, that you can then use for something else. It is simply about creating calculations useless.”

At a value of over $37,000 per coin, Bitcoin continues to expand around the world. In Central Asian countries, where dry weather is already putting pressure on freshwater supplies, increased Bitcoin mining activities will worsen the problem. In Kazakhstan, a global cryptocurrency mining hub, Bitcoin transactions consumed 997.9 GL of water in 2021. The Central Asian country is already dealing with a water crisis, and Bitcoin mining’s growing water footprint could exacerbate shortage.

De Vries suggests that approaches such as modifying Bitcoin mining software could reduce the energy and water needed for this process. Incorporating waterless renewable energy sources, including wind and solar, can also reduce water consumption.

“But do you really want to spend wind and solar energy on cryptocurrencies? In many countries, including the US, the amount of renewable energy is limited. Sure you can move some of these renewable energy sources to cryptocurrencies, but that means there will be anything else”. powered by fossil fuels. “I’m not sure how much you make,” he says.