 V between the two plates, one of them (the "ground" side) being held at a constant potential. The mass displacement current component dm/dt of the electron current dq/dt has nothing whatsoever to do with energy accumulation; it has only to do with the dissipation of energy that is happening simultaneously in all losses and loads in the circuit loop.
We reiterate that most ordinary capacitors have terrible internal movement, and accomplish as much energy dissipation as they do energy collection by permitting dq/dt and work performed upon the plates and dielectric to move them. The standard two-wire circuit also guarantees that all such dq/dt current "through" the capacitor is passed back through the source against its back EMF, doing an equal amount of work in the source to dissipate its separation of charges and "destroy" the source.
An ideal capacitor does not pass dq/dt, but only massless displacement current as theorized by Maxwell to save current continuity in a circuit containing a capacitor, and hence to save Ampere's current law. That is, an ideal capacitor is a dm/dt blocking device. However, the capacitors utilized in normal circuits are not ideal capacitors at all. By allowing the plates to move, electron current dq/dt is created on both sides of the capacitor. Otherwise there would not be a ground return dq/dt, but only a ground return dØ/dt. This dØ/dt would not and does not push electrons back up through the source against its back EMF; else the ground side of the source, which is engaged in continuous dØ/dt exchanges with the vacuum, would produce destructive amperage dØ/dt in the battery or potentialized source, against its back EMF, while it was simply sitting on the shelf. In fact, a flow of dØ/dt continually runs from the vacuum to the positive terminal, then through the inside of the battery to the negative terminal, and thence back to the surrounding vacuum. Also, the incoming flow from the vacuum "splits" at the positive terminal, where one branch flows inside the source to the negative terminal, and the other branch flows through the external circuit to the ground return line, and thence to negative terminal and back to the vacuum. In the external circuit, the dØ/dt hooks to free electrons and moves them as ordinary dq/dt. In the internal circuit inside the source, the electrons are restrained, hence they only move when their restraint is overcome.
Displacement Current dØ/dt Is Real
In recent years, SQUID detectors have been utilized to detect the magnetic field created between the plates (at right angles) by the displacement current dØ/dt between the plates, providing strong evidence that displacement current is physically real. The best proof that it is real is a charge blocking device, two isolated circuits using energy collection and shuttling, and overunity powering of loads in the secondary circuit.
A Problem With Ammeters and Measurement of dØ/dt
Note that an ammeter cannot differentiate between displacement current dØ/dt and normal current dq/dt. In the ammeter, the sample dØ/dt will couple to free electrons, producing a normal dq/dt inside the ammeter. The driving of this dq/dt through a precision resistance, e.g., is measured and the instrument is calibrated to show the dq/dt amperes flowing. One of the major needs of free energy researchers is the development of a good current meter that will differentiate between dØ/dt and dq/dt, and measure each one. Short of using a mass spectrometer to differentiate the mass current dm/dt, and comparison of those mass current measurements with an ammeter's measurements of the "current" dq/dt, and calculating the dØ/dt from that, I presently know of no way to precisely and simply measure and separate the two current components. I have been thinking of utilizing a multi-channel sampling meter set arrangement, where one channel uses a dm/dt blocking device such as the Fogal semiconductor in this respect, but have not yet developed the complete concept.
Better Solution: A Charge Blocking Device
A better solution than the capacitor or capacitive collector