How many cows to power the world?

Silly questions part one

Author

Cool Ishu
May 10, 2025

This is the first part of silly questions 1,enjoy!

How many cows would it take to power the world?

Answer:more than we have heres how…

Now this is the ultimate cow-energy breakdown! 🐄⚡

Let’s max out everything we can possibly extract from a cow for energy, including:

  1. 💩 Poop

  2. 💨 Burps

  3. 🍑 Farts

  4. 🐄 Body Movement

  5. 🔥 Body Heat

  6. 🍦 Milk (turned into biodiesel!)

  7. ⚡ Cow-Powered Devices (like treadmills)

🧮 Total Cow Energy — Ultimate Cow Power Plant™

1. 💩 Poop Energy

  • 22,000 kg/year × 5.25 MJ/kg = 115,500 MJ/year

2. 💨 Methane from Burps + Farts

  • ~250 L/day → 3,285 MJ/year (mostly from burps)

3. 🐄 Body Movement

Attach a cow to a generator like a treadmill:

  • A cow walking can produce about 0.5 horsepower = ~375 watts

  • Let’s say a cow walks 2 hours/day:

375 W×2×365=273,750 Wh=985MJ/year375 \, \text{W} \times 2 \times 365 = 273,750 \, \text{Wh} = \boxed{985 MJ/year}375W×2×365=273,750Wh=985MJ/year​

4. 🌡️ Body Heat Recovery

Cows give off about 1,000 watts of body heat.

  • With heat exchangers, we might recover ~10%

  • 100 W × 24 h/day × 365 = 876,000 Wh/year = 3,153 MJ/year

5. 🧈 Milk-to-Biodiesel (just for fun)

  • 1 cow produces ~8,000 L of milk/year

  • Milk fat can technically be used to make biofuel

  • Maybe ~5% of milk = usable fat = 400 L

  • 1 L of fat = ~35 MJ

  • 400 × 35 = 14,000 MJ/year

(We usually drink milk, but… science 😁)

✅ Total Per Cow:

Source

Energy (MJ/year)

💩 Poop

115,500

💨 Burps/Farts

3,285

🐄 Movement

985

🌡️ Body Heat

3,153

🧈 Milk Biodiesel

14,000

Total

136,923 MJ

🌍 Cows to Power the World

World needs: 600,000,000,000,000 MJ/year so

10 to the power of 12 times 600 divdided by 136,923

So we’d need ~4.4 billion “fully optiized” cows to power the entire world.

😆 Final Thoughts

That’s 3× more cows than we have now. But in our silly sci-fi world, we’d have:

  • Cows with poop digesters,

  • Fart-capture balloons,

  • Burp snorkels,

  • Generator treadmills,

  • Thermal vests, and

  • Biofuel milking stations.

Introducing: Moobattery Cow™ — the ultimate bio-battery!

POV:world be like Moo farm.

Thank you for reading I hope you liked it and please share.

This is one of my funny ones so: