Last year, as the price of Bitcoin surged above $17,000, environmentalists began to take note that the cryptocurrency’s energy consumption was likely to skyrocket as well. That’s because Bitcoin mining—the process by which Bitcoins are created and transactions tracked in a public ledger known as the blockchain—requires electricity. But no one knows exactly how much energy the secretive industry consumes.
To help fill this gap, Alex De Vries, a blockchain specialist at PwC’s Experience Center in the Netherlands, outlines a methodology to calculate just how much electricity the Bitcoin network uses in a year in a commentary in the journal Joule. His initial estimate is jarring: At minimum, De Vries found, the network could be using 2.55 gigawatts a year, on par with the energy consumption of the entire country of Ireland.
That number comes from estimating the number of devices connected to the Bitcoin network—which is estimated to have at least 10,000 nodes, but those nodes can be either single devices or a group of machines in a mining facility—and the processing efficiency of those machines. However, this approach can only ever provide researchers with a minimum estimate, De Vries writes, “first of all because the network doesn’t contain a single type of machine, but also because it doesn’t take cooling requirements into account.”
As machines mine for Bitcoin, they can produce as much heat as a space heater. Case in point: Circa 2010, I briefly had a roommate in college who built a computer that mined Bitcoin and heated the living room of a small apartment through a Boston winter. Large-scale mining operations have to counter all that excess heat with cooling technology, which requires additional electricity. But Bitcoin mining companies are usually no more transparent about energy expenditures for cooling than they…