Quantum miners would provide ‘massive’ energy savings for blockchain: Study
A pair of researchers from the University of Kent’s School of Computing in the UK recently conducted a study comparing energy consumption rates of current ASIC-based miners with proposed quantum-based solutions.
According to the team’s preprint research paper, the systems using quantum computing have demonstrably outperformed standard mining rigs in terms of energy efficiency:
“We show that the transition to quantum-based mining can result in an energy saving – at relatively conservative estimates – of approximately 126.7 TWH, or put differently the total energy consumption in Sweden in 2020.”
Bitcoin mining alone consumed more than 150 terawatt hours annually (as of May 2022), according to the paper, putting into perspective the potential impact the proposed quantum-based systems could have.
The pair’s conclusions were based on experiments comparing three different quantum mining systems with an Antminer S19 XP ASIC miner.
The quantum mining units were split between a system with a single layer of fault tolerance, another with two layers of fault tolerance, and one without dedicated fault correction features.
As the researchers point out, blockchain mining is one of the few areas of quantum computing where error correction is not a big deal. In most quantum functions, errors create noise that functionally limits a computer system’s ability to produce accurate calculations.
However, in blockchain mining, success rates with state-of-the-art classical systems are still relatively low. According to the research paper, “A classic Bitcoin miner is profitable with only a success rate of about 0.000070%.”
The researchers also note that, unlike classical systems, quantum-based systems can actually be fine-tuned over time for increased accuracy and efficiency.
Related: How does quantum computing affect the financial industry?
While quantum computing technology is still considered to be in its infancy, the very specific problem of blockchain mining does not require a full-service quantum computing solution. As the researchers put it, “a quantum miner is not, and need not be, a scalable, universal quantum computer. A quantum miner only needs to perform a single task.”
Ultimately, the researchers conclude that it should be possible to build miners using existing quantum technologies that demonstrate quantum advantages over classical computers.
Despite the potential energy savings, it should be mentioned that the researchers focused on a type of quantum computing system called a “noisy intermediate-scale quantum system” (NISQ).
According to the preprint paper, quantum miners should demonstrate “massive” energy savings at a size of around 512 quantum bits, or “qubits” — a term somewhat analogous to classical bits of data.
Typically, however, NISQ systems only operate with about 50-100 qubits, although that does not appear to be an industry standard.
While the energy savings may be feasible, the cost of building and maintaining a quantum computer system in the 512-qubit range has traditionally been prohibitive for most organizations.
Only D-Wave and IBM offer client-facing systems in the same range (D-Wave’s D2 is a 512-qubit processor, and IBM’s Osprey weighs in at 433), but their architectures are so different that comparisons between their qubit counts are seemingly meaningless .