Would the production of copper be an important consideration when we seek out some kind of answer about energy? Add into this the colour of the granite used in the Great Pyramid, especially the sarcophagus, and the colour of copper, and we might see a closer connection between the two.
In essence, rock has to be attacked for the ore, and the ore has to be broken down into finer grains for smelting, and anything with quartz in it is going to produce piezoelectricity when it is broken or such. In the case of granite in the pyramids, just sourcing the rock from its bed is going to give off a piezoelectric effect, and many indications are that copper tools were used.
This may have been the beginning of interest into electricity.
I'm not sure if the potential for copper-use could have been used in the following way back then, but telluric currents are accessible through placing metal forms into the ground, and energy storage is not needed if it can be accessed so readily from our 'Earth battery'. As the currents head away from the equator to the poles, several metallic forms at various distances could indicate another reason for the pit in the subterranean chamber: the last form accessing the stronger energy being passed along from form to form.
This does open up another possibility for why there is the well-shaft and grotto: a further metallic form embedded within the pyramid in some way, linked to by copper wire. The extension of this is the walls of the chambers: were they actually bare? The ante-chamber shows signs of the walls being attacked; and the gallery has those grooves within the third layer of blocks, not to mention the sockets along the side-ramps.
Just a thought.