Elon Musk wants a greener bitcoin. Has he got a plan or a pipedream?

Elon Musk says Tesla Inc. won’t use or accept bitcoin until he can be sure it’s produced sustainably. He may be waiting some time.

Musk announced his new position in a major U-turn on Wednesday, prompting speculation among some experts about whether he had a plan to wean the crypto industry off the fossil fuels that power “mining,” the energy-intensive process that creates coins.

Tesla could itself take an active role in helping make bitcoin greener by investing in new projects aimed at boosting the use of renewable energy in mining, according to more than a dozen cryptocurrency specialists interviewed by Reuters.