Electricity is the physical flow of electrons. This flow is an energy carrier and is used to deliver energy for electrically-powered devices and establishments. Electricity is a major problem for the cryptocurrency industry. Blockchain electricity consumption values vary due to the algorithm used for establishing consensus. Proof-of-work cryptocurrencies demand a lot of power to operate. As a major PoW cryptocurrency, Bitcoin electricity usage is estimated around the value equal to that of Ireland. Bitcoin mining electricity is the most consuming part of the cost. Blockchain electricity consumption is also an environmental problem, as the growing amount of power demand may lead to climate change. Fixing the problem of large electricity requirements is a field of work for many tech companies. The most used technology for reducing energy demand is a proof-of-stake consensus algorithm that changes the way mining is performed.