An estimate of those future quantum computers’ power consumption:
Olivier Ezratty at the Quantum Energy Initiative (QEI), an international organisation, says that one overlooked concern of building utility-scale [fault-tolerant quantum computers (FTQC)] is their potential energy consumption. At the Q2B Silicon Valley conference in Santa Clara, California, on 9 December, he presented preliminary estimates of it. Strikingly, several FTQC designs surpassed the energy footprint of the world’s largest supercomputers. [“Some quantum computers might need more power than supercomputers,” Karmela Padavic-Callaghan, NewScientist (17 January 2026; paywall)]
The people trying to break your password and other security features may be paying through the nose for the privilege. So how much energy do supercomputers consume?
The world’s fastest supercomputer, El Capitan at the Lawrence Livermore National Laboratory in California, needs about 20 megawatts of electrical power, which is approximately triple the energy consumption of the nearby 88,000-resident city of Livermore. In Ezratty’s estimate, two designs for FTQCs, scaled up to 4000 logical, or error-corrected, qubits, would require even more. The most power-hungry among them might need as much as 200 megawatts of power.
20 MW for a single supercomputer? My goodness. 200 MW for a FTQC?
With great ability comes big power bills.
I worked for a couple of years at a firm supporting supercomputers. The subject? I created relatively trivial software for tracking and reporting computer use so that the clients of supercomputing centers could be assured they were getting their money’s worth. From that came the observation that supercomputers were heavily scheduled and didn’t just sit around consuming power.
I doubt they’ll be turning FTQCs between runs, somehow.
