If we know Bitcoin through the prism of its monstrous consumption of electricity, we know it a little less through that of its water consumption. However, the observation is just as worrying.
In 2021, the Bitcoin industry consumed around 140 terawatt hours of electricity annually, or more than a third of the electricity consumed in France. According to estimates from the University of Cambridge, this consumption would have fallen slightly to 129 terawatt hours in March 2023. However, it is a sector that is largely lagging behind in its potential transition to sustainable energy. This gigantic industry operates in part thanks to Bitcoin mines. These are sets of very powerful computers used to verify transactions and add currencies to the blockchain. A recent study from the journal Cell Reports Sustainability (linked in the article sources), published on November 29, has just revealed that these installations are real water sinkholes.
An insatiable thirst
Alex de Vries, doctoral student at the University of Vrije (Amsterdam) and author of the study, looked into the little-known scale of water consumption attributed to Bitcoin. He explains : ” It’s hard to surprise me, given that I’ve already worked on the subject, but the numbers always seem staggering to me when I look at them. “. When Bitcoin reached its peak in 2021, water consumption was also logically reaching its peak, with mines requiring cooling to operate.
The total mining consumption then represented 1,600 gigalitres (one gigaliter is equal to one billion liters). Each Bitcoin transaction consumed on average 16,000 liters of water, the equivalent of a small swimming pool. That’s about 6.2 million times more water than a credit card swipe. Rather maddening.
Impacts and potential innovations
Bitcoin mining slowed slightly in 2022 due to falling prices. These having regained momentum, there is no chance that water and electricity consumption will not also start to rise again. According to de Vries, water consumption could rise again and exceed that of 2021 by reaching 2,300 gigalitres this year globally. To support his argument, he explains that some mines, for example in the United States, consume as much water as a city the size of Washington DC
So are there alternatives to reduce the impact of mining? Yes, even if it’s not miraculous. Systems for cooling computers by immersing computers in a non-conductive liquid can alleviate dependence on water. De Vries, for his part, leans more towards a formal removal of the mining process to verify transactions, as has been the case for Ethereum since last year. “ All water and electricity consumption would disappear overnight. It’s completely achievable » said de Vries.
The issues that link new technologies to the environmental context must always be considered by studying their different facets. Like CO emissions2 electric cars, which cannot be the only angle of analysis to study the question of their environmental impact. The pressure on Bitcoin’s water resources is another dimension, which has perhaps been too neglected, eclipsed by the question of energy consumption.
Sources: The Verge, cell
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