A pair of scientists from the School of Computing at the University of Kent in the UK recently conducted a study comparing the energy consumption rates of current ASIC-based miners with proposed quantum-based solutions.
According to the team's preprint research paper, systems utilizing quantum computing are significantly more energy efficient than standard mining equipment: "We show that, based on relatively conservative estimates, the transition to quantum-based mining could save around 126.7 TWH of energy, or in other words, the total energy consumption of Sweden in 2020."
According to the paper, Bitcoin mining operations alone consume more than 150 terawatt-hours per year (as of May 2022), looking at the potential impact that the proposed quantum-based system could have in the long run. The duo based their conclusions on Experiments comparing three different quantum mining systems with the Antminer S19 XP ASIC miner.
Quantum mining equipment is divided into a system with a single layer of fault tolerance, another system with two layers of fault tolerance and a system without any dedicated error correction functions. As the researchers point out, blockchain mining is one of the few areas in quantum computing where error correction is not a big deal. In most quantum functions, errors create noise that functionally limits the ability of computing systems to produce precise calculations. However, in blockchain mining, the success rate of state-of-the-art classical systems is still relatively low. According to the research paper, "a classic bitcoin miner is profitable with only about a 0.000070% success rate."
The researchers also point out that, unlike classical systems, quantum-based systems can actually be fine-tuned over time to improve accuracy and efficiency. While quantum computing technology is still considered in its infancy, the very specific problem of blockchain mining does not require a full-service quantum computing solution. As the researchers put it, "Quantum miners are not, and need not be, scalable general-purpose quantum computers. Quantum miners only need to perform one task."
Ultimately, the researchers concluded that it should be possible to build mining machines using existing quantum technologies that demonstrate quantum advantages over classical computers. Despite the potential energy savings, it's worth noting that the researchers focused on a type of quantum computing system known as a " noisy intermediate-scale quantum" (NISQ) system.
According to the preprint paper, quantum miners should demonstrate “substantial” energy savings at a size of about 512 quantum bits, or “qubits” a term somewhat similar to classical computing bits. Typically, however, NISQ systems only operate with ab out 50-100 qubits, although there appears to be no industry standard.
While Energy Saves May Be Feasible, The Cost of Building and Maintaining Quantum Computing Systems in the 512-QUBIT RANGE HAS TEEN PROHIBITIVE For M OST OST OST OSTOLY D-WAVE and IBM Offer The Same Range of Customer-Facing Systems (D-Wave's D2 is a 512-qubit processor, while IBM's Osprey weighs 433), but their architectures differ so much that ostensibly Looking at comparisons between their qubit counts is pointless.
