No - those piles are too large for OLE work.
Not neccesarily. OLE piles come in various sizes to support the ground conditions. I know of ones up to 1m diameter, although most are smaller of course.
They don't look like the standard OLE design ones either.
The piles visible in the video are CHS ones - "Circular Hollow Section", a standard type of pile used in an array of differing applications, OLE foundations just being one if them. They are fairly easy to procure and install so are the obvious choice when you are in a hurry. Usually vibrated and/or hammered down into the ground. Sometimes the centre is left as-is, sometimes it's excavated and rebar and concrete poured in, to make it much stronger. For this appliction they will almost certainly be infilled with concrete.
They also come in sections which is helpful for construction. You can bring them in a length suitable for the plant and access you have, then drive that in, weld a new section on top, then carry on driving down, weld, drive, repeat as required for however deep you want to go.