Anerg

Anerg is a fictional metric used in speculative science, thought experiments, and worldbuilding to discuss energy efficiency in physical systems. It denotes the portion of input energy that remains usable for work after accounting for irreversibilities and information-processing overhead. Unlike real-world exergy or thermodynamic efficiency, anerg is not standardized and definitions vary by author.

Typically, anerg is treated as a dimensionless ratio between 0 and 1, analogous to efficiency: anerg = useful work / total input energy, with additional terms to account for non-thermodynamic losses such as computational overhead or control-system dissipation. In this framing, a perfectly reversible process would yield anerg close to 1, while devices with high irreversibility or heavy computation would have lower values.

Uses: In science fiction and educational thought experiments, anerg is used to compare technologies, such as engines, batteries, or computational systems, particularly when highlighting the tradeoffs between energy, information, and control. It is also employed as a teaching tool to discuss exergy and the limits of practical efficiency.

Limitations: Because anerg is not a standard physical quantity, there is no universal method for measuring or reporting it. Different authors may include different overhead terms or choose different normalization. It should be understood as a conceptual tool rather than a precise experimental metric.