Few companies are as innovative as Tesla, and because the electric vehicle manufacturer is so far ahead of its competition in so many ways, the company continues to reach new heights. And while the brand has made billions of dollars in the past few years, it is always looking for new ways to make its cars more accessible and more advanced. With that in mind, Tesla recently promised that customers would be able to buy one of its products using Bitcoin. It didn't take long for that promise to come true, but now Tesla CEO Elon Musk has announced that this payment method has been suspended on the Model S and all other products. The reason? Sustainability.

Many naysayers have hypothesized that Musk's comments are a way of manipulating the world's largest cryptocurrency, but his reasoning makes sense. In the above tweet, Musk outlines how his company is "concerned about rapidly increasing use of fossil fuels for Bitcoin mining and transactions, especially coal, which has the worst emissions of any fuel."

The company isn't offloading its own Bitcoin reserves though, as these will be used for transactions again as soon as the mining of the cryptocurrency becomes cleaner. In the meantime, Tesla is analyzing which other cryptocurrencies are viable for its purposes, so long as they use less than one percent of Bitcoin's energy use per transaction.

Musk has previously shown interest in Dogecoin, a novelty currency that is more of a joke than a viable currency, and his comments about it when on Saturday Night Live suggested that he doesn't take this currency too seriously. But recently, Dogecoin has been taking off and could become more widely used as a result. Either way, it's clear that Musk does not have an issue with cryptocurrencies and sees their value - it's just a matter of making sure that the transactions made to buy a Tesla are better for the environment. Who knows? Maybe one day Musk will launch his own cryptocurrency. Stranger things have happened (Cybertruck, we're looking at you).