Musk decries bitcoin's 'insane' energy use after Tesla payment U-turn By Hyunjoo Jin and Subrat Patnaik Reuters (Reuters) -Tesla Inc boss Elon Musk on Thursday denounced the "insane" amount of energy used to produce bitcoin, doubling down on his sudden rejection of the cryptocurrency as a means of payment over environmental concerns. Musk, one of bitcoin's most ardent backers, tweeted a graph of bitcoin's power consumption and said: "Energy usage trend over past few months is insane." (https://bit.ly/33BYV8Z) That followed his tweet from Wednesday saying Tesla would no longer accept the cryptocurrency as payment for its electric cars because it came at a great cost to the environment, an about-face from his stance in March.