You're mostly right, in that a timing issue could be resolved through a temporary storage unit, though probably wouldn't have to put it underground. Likewise,

You're mostly right, in that a timing issue could be resolved through a temporary storage unit, though probably wouldn't have to put it underground. Likewise, batteries/capacitors/whatever would probably be set up on the electricity. A plant design would seem to want to control the flow rates of both. Overall, the parent comment's unlikely to be correct in its speculation that the reason for open-air capture is related to timing issues.