A number of U.S. lawmakers urged the country’s energy and environmental protection authorities to mandate that cryptocurrency miners disclose data on energy use, as seven of the largest mining companies were found to use as much power as all of the homes in Houston.

See related article: Bitcoin lobbyists rebut ‘misconceptions’ over environmental impact

Fast facts

• In a letter published Friday, U.S. Senator Elizabeth Warren and five other lawmakers wrote that the results of their investigation, which collected data from seven miners including Riot, Bitdeer, Stronghold and Marathon, are “disturbing.”

• The seven companies have accumulated over 1,045-megawatt capacities for crypto mining, according to the data cited in the investigation.

• The data revealed that “crypto miners are large energy users that account for a significant — and rapidly growing — amount of carbon emissions,” the lawmakers wrote.

• In May, the industry lobby network Bitcoin Mining Council (BMC) said crypto mining centers are “no different” than the facilities hosted or operated by Amazon, Apple, Google, Meta and Microsoft.

• The Bitcoin mining industry employed an estimated 58.4% sustainable energy mix in the first three months of this year, the BMC noted, citing a survey it conducted.

• In June, the New York State Senate said it passed a cryptocurrency mining moratorium bill that could block new permits and expansion for proof-of-work mining facilities using carbon-based energy sources.

See related article: Bitcoin hashrate slumps to lowest in over five months amid 100-degree-plus weather in Texas