I didn't intend to open up a can of worms with only one post, and add to further clutter in this thread.
This is a rhetorical question, no need for a response but you are certainly at liberty to do so.
Are you saying emphatically that capacitor can store only a charge, and never a voltage?
Are you stating that capacitors store only charge, and never energy.
Think about what an inductor stores, and whether it stores energy or not.
Ok, so I'm not smart enough to stay shut up... I apologize for the digression, but hopefully some precision and accuracy in the use of terms will help some with understanding exactly what's going on in CDI and LDI systems.
Yes, I am saying emphatically that a capacitor stores charge, or more precisely a difference in charge. Voltage and energy are properties of the system due to the fact that there are separated charges that are stored.
This isn't just word games. What "the thing is", and what are "properties that are due to the thing" matter.
Let me move this into a realm where day-to-day physical intuition is helpful.
Imagine you have a rock. The rock stores mass. That's all the rock stores.
Now put the rock at the top of a hill. Assume gravity exists. The rock now "has potential energy". The more mass you store in the rock, the more potential energy it has.
Is the rock storing the potential energy? Is the hill storing the potential energy? What about the gravity?
Keep the rock exactly where it is, but bulldoze the valley below it full. Suddenly, no potential energy. We didn't change the rock at all, so it can't be the rock that's storing the potential energy.
Keep the hill exactly as it was but make the rock smaller. Suddenly, less potential energy. We didn't change the hill at all, so it can't be the hill storing the potential energy. We also didn't change gravity in either of these, so the energy isn't stored in the gravity.
The answer to all 3 questions is "no", the potential energy isn't stored in the rock, the hill, or in gravity.
The potential energy is instead a property of the combined system of the rock, hill and gravity.
If one misunderstands the underlying physics and just says "well, I can work out any value from the others, so they're interchangeable", one ends up in situations where it looks like one can create or destroy energy without touching the thing one claims contains the energy. This way, madness lies.
Like rocks store mass, capacitors store difference in charge. The closest I can currently get to physical-intuitioning the capacitor situation would be the following:
[edit - crap - Friday afternoon brain is really toast! pull, not push!]
Imagine after you've charged your capacitor, if you grab the two plates, and physically move them apart. Suddenly there is more stored energy, even though you haven't changed what you put in. The same charges/difference-in-charge continues to exist, but the energy changes (For the physicists, we're going to ignore the fact that I did work on the system when I separated the plates - I know the energy did not just appear...) The same _physical_ stuff is still stored, but the energy changes because the overall system changed. Move the plates back together, and the energy is back to where it started. Still haven't changed what's literally stored - an excess of charges on one plate and a depletion on the other - but the energy again changes. Ergo, the energy is a property of the complete system.
It's not a perfect analogy, but it's the best I can do between things on a Friday afternoon.
... my first inclination is to say that inductors store a magnetic field, and that it's the magnetic field that stores energy, but I'll need to ponder that a bit before I'm sufficiently confident to argue specifics.