This founder is teaching chips how to recycle (their energy)
Throughout the history of the computer chip, engineers have treated waste heat as an inevitable cost of a calculation. Hannah Earley, however, thinks it’s a design choice.
Conventional computer chips generate heat as a byproduct of their calculations. This happens because, during computations, chips erase intermediate data they no longer need, releasing energy in the form of heat—a process similar to braking a car at every intersection, which wastes momentum and fuel. This inefficiency is treated as an unavoidable cost in chip design. For example, data centers, which power everything from cloud services to AI, consume vast amounts of electricity, much of which is lost as heat. The global data center energy use reached approximately 240–340 terawatt-hours in 2022, accounting for about 1–1.5% of total global electricity consumption. This waste highlights the need for more efficient computing methods to reduce energy loss and environmental impact.
Reversible computing is a theoretical approach that aims to eliminate the energy waste seen in traditional chips by retaining intermediate data instead of erasing it. This allows computations to run backward, recovering some of the energy used. The idea was first proposed over 50 years ago but was considered impractical with existing technology. Reversible computing is based on the principle that information is physical and that erasing data increases entropy, which generates heat. By avoiding erasure, reversible computing could theoretically make chips far more energy-efficient. However, implementing this concept requires rethinking chip design at a fundamental level, including the hardware components used to store and reuse energy.
Vaire Computing, cofounded in 2021 by Hannah Earley and Rodolfo Rosini, is developing chips that use reversible computing. Earley, the company’s chief technology officer, designed a patent-pending component called a resonator—a microscopic chip part that stores recovered energy for later use. She compares it to a glorified pendulum, as it oscillates to capture and reuse energy. In 2023, Vaire achieved a key milestone: a chip with a resonator that recovered more energy than it consumed, even after accounting for the energy needed to power the component. This result demonstrated that reversible computing could work in practice, moving the field from theory to a tangible proof of concept.
Hannah Earley’s interest in reversible computing began during her PhD at the University of Cambridge, where she initially studied how materials like DNA could perform calculations. After reading a 1999 PhD thesis by Michael Frank, a pioneer in reversible computing, she shifted her focus to the physical limits of computation. She developed software to convert ordinary programs into reversible ones and eventually cofounded Vaire Computing with Rosini in 2021. The company has since raised over $12 million and hired Frank as a senior scientist. Earley’s work represents a significant departure from traditional chip design, aiming to rebuild computers from the ground up with energy efficiency in mind.
Despite the 2023 breakthrough, reversible computing remains in its early stages. The technology will require further development and convincing demonstrations to attract industry support for commercialization. One major challenge is integrating these radically different chips into existing devices and manufacturing systems, which are designed for traditional chip architectures. Earley emphasizes the need to rethink every aspect of computer design, from the ground up, to fully realize the potential of reversible computing. The goal is not to refine current chips but to rebuild them with energy recovery as a core principle, potentially transforming how computers are built and used in the future.
