# Serenity 1. Serenity is the fourth and final phase of [[Ethereum (blockchain)]]. Because [[Proof of Work (PoW)]] entails an enormous waste of energy, the developers want to find an alternative in this phase. The Ethereum Network is expected to be converted from PoW to [[Proof of Stake (PoS)]]. Apart from this, the network should be faster, more efficient, easier for beginners and more resilient against the closure of mining capacity. As with Bitcoin, Ethereum [[Mining|mining]] requires a massive amount of energy; rough estimations put energy use at levels similar to the entire nation of Estonia. By switching to PoS, it becomes possible for individuals to perform mining by connecting to a computer network, thereby reducing consumption. According to Alex de Vries, energy consumption after the switch to Proof of Stake will fall to near negligible levels.