Elon Musk has stated that Bitcoin is based on energy, not fiat currency. Unlike governments’ ability to create unlimited amounts of money through fiat, Musk believes that energy cannot be artificially created or faked. This assertion was made in agreement with financial outlet ZeroHedge and highlights the differences between traditional currencies and cryptocurrencies like Bitcoin.
Source: https://seekingalpha.com/news/4503936-elon-musk-links-bitcoins-energy-base-to-ai-boom