The voltage has tended to increase over time and in the modern era the voltage is usually 2,000 to 2,200 volts at seven to twelve amps.”

That means it takes 14,000 to 26,000 watts.

There are many kinds of electric chairs and I doubt they all have the same energy needs. You’ll have to research that yourself.

Its the amps (current) that kills you not the volts. 42 volts can be lethal while 4000 volts can be perfectly safe.

Someone can throw a bucket of water over you and youd be fine, but the same volume of water squirted at you with a high-pressure water jet could cut you in half.