Human Power and Metabolism

How much power does a human generate? Can you power your home by exercising?

Basal Metabolism

Even at rest, your body burns energy to keep you alive:

daily_basal_energy = human_basal_power * day

6.9e+6 [6.1e+6, 7.8e+6] watt s {energy}

At rest, you use about 6.9e+6 [6.1e+6, 7.8e+6] watt s {energy} per day.

In food calories (kcal):

daily_basal_kcal = daily_basal_energy / calorie

1.7e+6 [1.4e+6, 1.9e+6]

That's roughly 1.7e+6 [1.4e+6, 1.9e+6] kcal/day - your minimum to survive.

During vigorous exercise, power output increases significantly:

exercise_power = human_active_power
power_increase = human_active_power / human_basal_power

5.0 [3.7, 6.5]

During exercise, you output 400 [300, 500] watt {power}, which is 5.0 [3.7, 6.5]x your resting rate.

A typical US household uses about 30 kWh per day:

home_daily_energy = 30 kWh

30.0 kW hour {energy}

How long would you need to exercise at peak output?

exercise_time = home_daily_energy / human_active_power

75 [60, 100] hour {time}

You'd need to exercise for 75 [60, 100] hour {time} at peak output - clearly not feasible!

A human at rest outputs about the same power as:

equivalent_bulb = human_basal_power

80 [70, 90] watt {power}

You're basically an 80 [70, 90] watt {power} light bulb!

Your blood carries oxygen and nutrients to power this metabolism:

blood_cycles_per_day = (human_blood_volume * 1440) / human_blood_volume
cardiac_output_estimate = human_blood_volume * 70 / minute

5.8 [5.2, 6.4] liter / s {flow}

Your heart pumps your entire blood volume roughly once per minute during rest.

Over a lifetime, how much total energy does a human consume?

lifetime_energy = human_basal_power * human_lifespan
lifetime_energy_gwh = lifetime_energy as GWh

0.051 [0.042, 0.061] GWh {energy}

A human consumes roughly 0.051 [0.042, 0.061] GWh {energy} over their lifetime - equivalent to:

gasoline_equivalent = lifetime_energy / energy_density_gasoline

1.3e-4 [1.0e-4, 1.5e-4] (watt year kg) / J {mass}

About 1.3e-4 [1.0e-4, 1.5e-4] (watt year kg) / J {mass} of gasoline worth of chemical energy!