It is the latest change of tack from the tech entrepreneur - after Tesla said earlier this year that it would accept Bitcoin for vehicle purchases but then in May that it would stop doing so.
Bitcoin rose 8% to more than $32,000 on the comments late on Wednesday, having suffered further volatility earlier this week that saw it tumble below $30,000.
But Mr Musk sounded a more positive note when he spoke about the reasons behind the move at a conference.
"I wanted a little bit more due diligence to confirm that the percentage of renewable energy usage is most likely at or
above 50%, and that there is a trend towards increasing that number, and if so Tesla would resume accepting Bitcoin," he said.
"Most likely the answer is that Tesla would resume accepting Bitcoin.