In article ,
Tim R wrote:

Certainly. But you can measure the speed of the water in the hose, and
there will be a difference. Or if you want to be closer to the
electrical load scenario, have the water in the hose run a small
turbine, and measure the energy of the water before and after. You will
find the mass unchanged and the velocity decreased, so kinetic energy of
the water molecules has decreased by exactly the amount that went into
work done by the turbine (and heat and pressure losses).

What is the equivalent change in the electron stream going through the lamp?

I believe it's one of potential energy, created by the "packing
together" of electrons in opposition to their electrostatic repulsive
force.

In a battery, or a capacitor, you charge up the device by segregating
the electrons onto one side of the barrier (packing an excess of them
in) and creating a corresponding deficit of electrons on the other
side. Because the electrons have the same charge, and you're putting
more of them on one side than you have protons, and because like
charges repel, you have to do work to "pull" the electrons out of the
"+" side of the accumulator and "push" them into closer proximity on
the "-" side (overcoming the net repulsive force). It's analogous to
pumping water up-hill, and storing potential energy in the water's
increased altitude (gravitational P.E.).

Allowing electrons to flow through your circuit is analogous to
letting water flow down-hill. The electrons aren't individually
changed by this process, but they end up less tightly spaced, and in
an environment with relatively more positively charged particles to
counteract their tendency to repel one another.

That's how I see it, anyway.