In May 2021, Elon Musk tweeted that bitcoins use a lot of fossil fuels, so Tesla will not use the cryptocurrency for transactional purposes. This dipped the surging market rating of cryptocurrencies. The physical currencies now in circulation have all been issued by your country’s reserve banks. Instead of going through these central money issuers, cryptocurrencies use ledgers called as blockchains. CNBC’s crypto specialist Ryan Browne explains how miners have to run multiple computers to prevent fraudulent transactions. These activities need a lot of energy. According to a recent Cambridge University study, bitcoin mining takes up about 116 terawatt-hours of energy per year, nearly 0.5 percent of electricity consumed worldwide.