There are much easier and cheaper ways of generating megavolts of electricity, I think the biggest barrier would be getting someone who knows enough about this to build it despite their skepticism about the validity of it.
Sure but for creating fairly uniform/gradual fields of static electricity over a large space?
Electrostatic precipitators exist but they aren't large. Everything else I'm aware of that works on larger scales fails to satisfy the uniform/gradual aspect.
