How big a cable would it need to power a light on Mount Everest?

That’s an interesting question don’t you think? Let’s see now. The height of the mountain is over 29,000 feet, but that of course is vertical height from the ground.

If you ran a cable up to the top of Mount Everest, it would go up at an angle following the contours of the ground. Like the hypotenuse of a triangle.

Using basic geometry, if the base of the triangle was known, and or the angle of the hypotenuse it would be possible to calculate. But since these are unknowns, we could estimate and say the cable would have to be a lot more than 29,000 feet.

Now, 29,000 feet is roughly 5.5 miles.

Ah yes but, you may say, is there a power outlet at the base of Mount Everest? It’s all very well having a light with a cable running from the top to the base but what do you connect the cable to?

On the Discovery Channel programs showing expeditions tackling the biggest mountain in the world, they usually set of from some remote Tibetan village and walk for days before they even get to the base of the mountain. In miles, the distance from the village to the base camp is probably over fifty.

All of this is assuming the village has electrical power available. If it doesn’t, there is probably another couple of hundred miles to the nearest large town.

So, we now have a cable over 255.5 miles long, just to put a light on the top of Mount Everest.

The next question is how big a diameter must the cable be?

Without going too deeply into technical explanations, if you had a 250 mile long cable the same size you have in your house powering your beside light, by the time the electricity got from the plug socket to the light, there would be almost no power left. This is because of voltage drop. If the cable is small in diameter, the voltage drop is higher than if it was a large diameter.

So, the way to overcome this would be to increase the diameter of the cable to several sizes bigger than you would find in your house. It would cost a king’s ransom to install and result in a huge electricity bill every month.

There we have it then.