As the pushback over environmental concerns of the blockchain industry continues, a recent report by Solana says that a single transaction on the network uses less energy than just two Google searches.

Fast facts

  • Completed under the guidance of an independent energy and climate advisor, Solana’s November Energy Report found that a single Solana transaction uses 1,837 joules of energy, while a Google search uses 1,080 J.
  • A joule is a standard unit of measurement of energy used in electricity, mechanics, thermal energy and other scientific applications. It is equal to the amount of energy required to produce one watt of power, for one second.
  • For comparison, the report states that running an LED light bulb for one hour uses 36,000 J, while running a typical refrigerator for an hour uses 810,000 J. The power disparity is even greater when compared to other blockchains; a single transaction on the Ethereum blockchain was stated to be 692,820,000 J, while one on the world’s largest blockchain Bitcoin requires an astronomical 6,995,592,000 J — the same amount of power as running a refrigerator for almost an entire year.
  • These two blockchains are so energy intensive because they rely on a consensus mechanism known as proof of work, where node operators are rewarded with Bitcoin or Ether for validating transactions on the network by solving highly complex cryptographic computations. As the network grows due to the increasing value and further adoption of these assets, so too does the energy requirements as more computers compete to be the first to crack the cryptographic code to earn the reward.
  • One of the most anticipated upgrades of the transition to Ethereum 2 is a switch from this PoW model to a proof of stake, which will drastically reduce the energy requirements of validating the network — by up to 99.95%, according to Ethereum’s estimate. The probability of miners in PoS networks of being rewarded is in line with how much they have staked back into the network. The report found the estimated energy requirements for an Ethereum 2 transaction is 126,000 J.
  • Solana is able to run on such low energy requirements by combining proof of stake with another consensus mechanism known as proof of history, which acts like a cryptographic clock that enables nodes to agree on the time order of on-chain events before being verified through a PoS method. It’s the use of this PoH model that also allows Solana to have increased transaction speeds — it’s capable of running 65,000 transactions per second, making it 2,000 times faster than Ethereum.