Cryptomining Capacity in U.S. Rivals Energy Use of Houston, Findings

Seven of the largest Bitcoin mining companies in the United States are set up to use nearly as much electricity as all the homes in Houston, according to data disclosed Friday as part of an investigation by congressional Democrats who say miners should be required to report their energy use.

The United States has seen an influx of cryptocurrency miners, who use powerful, energy-intensive computers to create and track the virtual currencies, after China cracked down on the practice last year. Democrats led by Senator Elizabeth Warren are also calling for the companies to report their emissions of carbon dioxide, the greenhouse gas that is the main driver of climate change.

“This limited data alone reveals that cryptominers are large energy users that account for a significant — and rapidly growing — amount of carbon emissions,” Senator Warren and five other members of Congress wrote in a letter to the heads of the Environmental Protection Agency and Department of Energy. “But little is known about the full scope of cryptomining activity,” they wrote.

Research has shown that a surge in cryptomining is also significantly raising energy costs for local residents and small businesses, and has added to the strain on the power grid in states like Texas, the letter noted.

Cryptocurrencies like Bitcoin have grown exponentially since they were introduced more than a decade ago, and in recent years, so have concerns over cryptomining, the process of creating a virtual coin. That process, a complex guessing game using powerful and power-hungry computers, is highly energy intensive. Worldwide, Bitcoin mining uses more electricity than many countries.

Earlier this year, a group of congressional Democrats launched an investigation into energy use at the country’s largest cryptomining companies. They asked seven cryptomining companies for data on their operations, and the group’s findings, issued Friday, are based on the companies’ responses.

That data showed that the seven companies alone had set up to tap as much as 1,045 megawatts of power, or enough electricity to power all the residences in a city the size of Houston, the nation’s fourth-largest city with 2.3 million residents. The companies also said that they plan to expand their capacity at an eye-popping rate.

One of the largest cryptomining companies in the United States, Marathon Digital Holdings, told the probe that it operated almost 33,000 highly specialized, power-intensive computers, known as “mining rigs,” as of February, up from just over 2,000 at the start of 2021. By early next year, it intends to get that number up to 199,000 rigs, an almost hundredfold increase in two years, it said.

The company currently operates a cryptomining center powered by the Hardin Generating Station in Montana, which generates electricity by burning coal, the dirtiest fuel. But in April, Marathon announced that it would be moving those operations to “new locations with more sustainable…