To become a green blockchain, the Ethereum blockchain switched from a proof-of-work (PoW) consensus mechanism to a proof-of-stake (PoS) consensus mechanism on September 15. The overall amount of energy used by the Ethereum network immediately and significantly decreased after that.
The upgrade immediately reduced the network’s energy usage by 99.9%.
Ethereum used between 46.31 terawatt hours (TWh) and 93.98 TWh of energy annually until the Merge upgrade in 2022. On December 26, 2019, 4.75 TWh of energy was used by Ethereum, the lowest amount ever.
Ethereum’s energy consumption decreased by almost 99.9% starting on October 15, the day of the Ethereum Merge, and it has remained low ever since. As a result, the network now has an annual carbon footprint of 0.1 million tonnes of CO2 (MtCO2).
The electrical consumption is as low as 0.03-kilowatt hours (kWh) and the carbon footprint is 0.01 kgCO2 when expressed in terms of individual Ethereum transactions. To keep its network secure, Ethereum currently consumes less than 0.01 TWh of energy annually. Before the Merge, the network consumed about 112 TWh annually. Currently, the Ethereum network uses less energy than Netflix, online games, or payment systems like PayPal. PoW mining for Bitcoin, in contrast, uses about 200 TW a year.
The community has expressed worries about the blockchain’s centralization and increased regulatory scrutiny despite the celebrations around Ethereum’s switch to PoS. While supporters of Ethereum assert that anyone with 32 ETH can become a validator, it is crucial to remember that 32 ETH, or around $41,416, is a considerable sum for a beginner or an average trader.
The centralization component was immediately apparent following the Merge since only two addresses were responsible for 46.15% of the nodes used for data storage, transaction processing, and adding new blockchain blocks.