Image text: More generally, with great power comes great dEnergy/dt.

Good old uncle Ohm.  In this, not-quite-sure-it-happened-this-way, comic, Ohm's nephew (I'm presuming they both have the last name Ohm) is being given what would later become part of Ohm's law of electricity.

I = V/R

It relates the current I, to the voltage (electrical potential) V and resistance R.

Power is just current multiplied by voltage P = IV.  Through substitution with Ohm's law we can see that power is also equal current I squared times resistance R.

The reason old uncle Ohm is stating it this way is probably because he's making a pun on how Peter Parker's (Spiderman's) uncle would relate his own dying words to his nephew many decades later.  "With great power comes great responsibility"