Elon Musk has opened the door to Tesla once again accepting Bitcoin for payment, saying it will happen when miners use 50% clean energy.

Tesla was one of the first major companies to adopt Bitcoin as a form of payment, but changed course just weeks later. When Musk informed the world via Twitter, he cited the environmental impact of Bitcoin mining as the primary reason.

It appears that decision is not set in stone, however, as Musk has said Tesla would reconsider when Bitcoin miners are relying on clean energy for a substantial portion of their operations.

This is inaccurate. Tesla only sold ~10% of holdings to confirm BTC could be liquidated easily without moving market.

When there’s confirmation of reasonable (~50%) clean energy usage by miners with positive future trend, Tesla will resume allowing Bitcoin transactions.

— Elon Musk (@elonmusk) June 13, 2021

The environmental impact of crypto mining is becoming an increasing concern. When announcing his country would adopt Bitcoin as legal tender, El Salvador President Nayib Bukele said the country’s engineers were working on using geothermal energy for mining.

Musk’s promise may provide further incentive for miners to start using clean energy.