There are lots of legal ways to hook up a genny- whether wind or any other type. There is also a lot of information out there- but, as you discovered, not all of it is as informed as it could be.
The "alternative power" crowd unfortunately has two sub-groups to be wary of. The first are the handimen, who can't be bothered to learn or ask questions- but freely re-invent the wheel daily. The other group has a political axe to grind, and blithly assert that the PoCo is inherently evil, deserves to be messed with, and that codes are a bunch of irrelevant silliness.
It can be hard to separate the wheat from the chaff sometimes.
Anyway, as to your questions:
- The ANSI spec for conduit differs from the spec for water pipe in that conduit is required to be have a "smooth finish" inside. The water pipe spec is silent on the mater. Nor does the ANSI spec define "smooth". For the most part, EMT ought to be adequate, assuming you can support it regularily.
- Unless marked otherwise, welding cable is rated only for 100 volts. Look for the marking. Then, look for connectors that are intended for FINELY stranded cable; these will often have ferrules twice as long as the "standard" ones, or two set screws, rather than one.
- We've recently discussed the issue of receptacles. There really is not an "approved" patern for EVERY use. Before NEMA patterns- which wasn't all that long ago- there were several patterns used that were targeted at multiple voltage/amp classes. These patterns are still available.
The plan is to have different systems to be non-interchangeable.Most any pattern can be used. And MARK everything. The NEC often refers to 'qualified personnel,' and this is why!
- As far as UL listing goes, well, there's a lot of areas where UL is not very strong. Power generation, power company equipment are such an area. Control panels are also an area where regulation is weak.
The heart of the system is the transfer switch. A simple one will simply isolate one system from the other as the switch is made; fancier ones will ensure that the genny is running "in time" to the grid.
In most cases, the simplest way is to have the genny only charge the batteries, then have the batteries feed the transfer switch. This helps isolate things.
There are PoCo and overcurrent issues, though. This is one area where it pays to have an electrician experienced in such stuff at your side.
