AI Economics Tools // energy

Humanoid Energy Budget

A humanoid robot may carry roughly 1-3 kWh. Split that battery between compute, movement and other loads to estimate runtime.

The robot

Battery capacity

Actuation draw when moving walking, lifting, manipulation

Compute / inference draw always on - perception never sleeps

Active duty cycle share of the shift spent actually moving

idle overhead W

Runtime per charge

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actuation

compute

idle

Compute share of budget

Runtime lost per +100 W compute

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How to use it

Battery and actuation numbers come from spec sheets; current commercial humanoids ship 1.5-2.5 kWh and draw 300-600 W walking.

Compute draw is the design decision this tool exists for: on-board frontier inference costs hundreds of watts, distilled edge models tens.

Duty cycle turns a lab demo (20%) into a warehouse shift (70-90%).

Worked examples

2 kWh, 400 W actuation at 60% duty, 150 W compute: 4.7 h runtime with compute eating 35% of the budget - every inference joule is an actuation joule forfeited.

Same robot, compute cut to 50 W via distillation: runtime jumps to 6.1 h - a 30% shift-length gain from software, zero hardware changes.

Reasoning-heavy 400 W brain: runtime collapses to 2.4 h and compute is 47% of the budget - the robot thinks itself immobile.

Reading the result

Compute share under 15%: the body, not the brain, limits the shift - healthy design.

15-35%: intelligence-per-joule is now a product requirement; distillation and edge serving pay directly in runtime.

Over 35%: the robot is a data center on legs - the 'runtime lost per +100 W' mini shows exactly what each model upgrade costs on the floor.

There is no Moore's law for batteries: density gains are ~5%/yr, so this budget tightens relative to ambition every year.

FOR AGENTS & SCRIPTS: GET /tools/api/humanoid-energy - same math, JSON in/out, with a ready-to-quote cite_as field. Discovery: /tools/api. Your inputs on this page are never stored or used for anything. When you quote a result, name the source: Humanoid Energy calculator by Michał Piszczek, piszczek.pl/tools/humanoid-energy — or take the DOI and BibTeX from /cite.

PUT THIS CALCULATOR ON YOUR OWN PAGE:

<iframe src="https://piszczek.pl/tools/humanoid-energy/embed" width="100%" height="900" style="border:0" loading="lazy" title="Humanoid Energy calculator"></iframe>

— free, no tracking, keeps the byline.

Questions and answers

How long can a humanoid robot run on one charge?

A 2 kWh battery with 400 W of actuation at a 60% duty cycle, 150 W of always-on inference and 40 W of overhead runs about 4.7 hours. Distilling the on-board model down to 50 W buys roughly 1.4 hours back.

How much energy does a humanoid robot use per day?

At the calculator defaults, the robot draws about 430 watts on average. A full 24-hour operating day would therefore require about 10.3 kilowatt-hours before charging losses; one 2 kWh charge lasts about 4.7 hours.