Owner Elon Musk tweeted a statement on Wednesday (May 12) to say his company is “concerned about rapidly increasing fossil fuels for Bitcoin mining’.

“We are concerned about rapidly increasing use of fossil fuels for Bitcoin mining and transactions, especially coal, which has the worst emissions of any fuel,” he wrote.

“Cryptocurrency is a good idea on many levels and we believe it has a promising future but this cannot come at great cost to the environment.

“Tesla will not be selling any Bitcoin and we intend to use it for transactions as soon as minig transitions to more sustainable energy. We are also looking at other cryptocurrencies that use <1% of Bitcoin’s energy/transaction.”

Bitcoin mining is the process by which a new Bitcoin enters into circulation, and is a pain-stakingly slow process involving sophisticated computers solving complex maths problems. Those who mine Bitcoin essentially spend hours verifying transactions to ensure a Bitcoin is not spent twice, and thus prevent counterfeiting. Due to the lengthy process, they are rewarded with a new Bitcoin.

The computers often rely on electricity which is generated by burning fossil fuels, in particular coal, in areas where Bitcoin mining has become popular, such as China.

Following the tweet by Mr Musk, the value of Bitcoin fell sharply. One Bitcoin is currently worth around £35, but before his tweet, it was worth around £40.