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3 months ago in Engineering , Thermodynamics By Vipul

Is it time to retire "efficiency" as a metric?

Efficiency is just output over input. But that feels too simple for real-world systems that degrade, idle, and interact. Do we need a new law for "useful energy"?

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By Anusha Answered 1 month ago

Yes, and engineers already have a better word for it: exergy. It's the usable energy, the stuff that can actually do work, accounting for entropy and real-world conditions. A new universal metric based on exergy, duty cycles, and system-level integration would let us compare a solar panel, a human heart, and a Mars rover on equal footing. It's not about being efficient on paper. It's about being useful in the world.

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