Interest in greener cryptocurrencies is growing after Tesla CEO Elon Musk announced that his company, citing environmental concerns, was suspending the use of Bitcoin to purchase vehicles.

Musk’s announcement sent the price of Bitcoin into a tailspin, with the virtual token dropping from more than $57,000 to below $49,000 in less than 24 hours. Musk, a billionaire who is known for his investments in cryptocurrency, had raised concerns about the impact of mining Bitcoin, which is the energy-intensive process of minting new coins.