What-If / Green Cows – invalid results due to missed energy source

The what-if.xkcd.com about Green Cows missed a few important factors that can help reduce the energy a cow needs. The original suggestion was chlorophyll in the cow’s skin would produce 2-4% of cow’s daily energy need of 50 million joules.

However, our fearless scientist neglected some additional ways a cow could be genetically improved to reduce its energy needs.

1. Methane gas combustion
2. Increasing cow’s surface area
3. Improved locomotion

Methane Gas Combustion

Methane gas from cow farts produce 12-17% of the methane produced in the world. This is about 6million metric tons. Each molecule of methane will release 2 water molecules, CO2, and 891kJ when burned. Therefore the cow can reduce its energy need with a small internal turbine that will generate power for the cow machine + water to drink. I will leave it to the reader to determine the extra benefit.

Increase the cow’s sunlight collection surface

We should genetically cross the cow with a porcupine giving the new cowupine a greater surface area to absorb sunlight.

This would have the benefit of making events like rodeos and bullfight way more interested and balanced.

Improved locomotion

The kangaroo is the most efficient traveler. Genetically cross the cowupine with the kangaroo to make a cowuroo.