Be very careful with the advice you get from Woodland Scenics tech support or posted specs! I just went through quite a difficult time with my recent purchase of their Smith Bros. Television & Appliance store.
Before I purchased it, I confirmed that, as has been detailed above, their Just Plug hub can be powered by AC or DC at or about track voltage, since I didn't want to pay for their IMHO overpriced 24 VDC wall wart and instead wanted to use a surplus 20 VDC wall wart I had at hand. Long story short, the ceiling LED in the piece did not fully light when I got it, and instead only flickered. The nice folks at WS sent me a replacement LED and a replacement four-plug splitter that connects all the LEDs under the piece. No joy -- neither the original nor replacement LED worked with either the original or replacement splitter when everything was connected to one splitter, but I *did* find that unplugging *any* other LED from the splitter, or putting the original *and* replacement LEDs on a separate splitter from the rest, had them *all* working! When I told WS about my homebrew power supply, though, *that* became their only answer, despite the fact that I had by that point tested the piece with track and accessory voltage AC and DC, with exactly the same (lack of) results, and despite the fact that WS also offers a two-nine-volt battery (i.e, 18 volt!) power supply as an OEM option. So, to recap, yes, the Just Plug Hub can be powered by either AC or DC, by any power supply that approximates track or accessory power, but there may be something hinkey going on with the Smith Bros. piece that still remains undiagnosed!
Don't cry for me, though -- I just ran a second Just Plug line from the Hub for the second splitter I used to connect the overhead LED and the replacement LED I installed as a porch light, which can be separately controlled to yield a 'night' setting, and I still have most of a spool of extension wire left over! Here's a short video of the finished piece in action:
