Your best bet is a generator and lights. There really isnt a useable alternative. I have tried some other methods, and they just weren't reliable enough to actually get any shots.
The most expensive part of the setup is a generator that will power your lights. Most halogen lights stands require 1000w for just two lights. You are going to need at least 2 stands to light a spot effectively. You can get away with using a cheaper lower power generator if you use LEDs.
I personally use a cheaper generator and run 4x 50w LED floodlights on some old tripods and construction light stands.While it was still on the expensive side ($100 cad for a 1000w generator, 4X $30 cad per LED light, $40 cad for construction light tripod, 3X $30 cad 50 foot extension cords+tripods that I had laying around = 350 ish) It is really portable. My whole setup fits into two rubbermaid totes, and easily fits into my car.
The vast majority of the urban videos that I have shot have been with this setup, and while it is not as good as using a larger generator and halogen construction lamps, it was pretty close to half the price.
Here is an example:
If you are even remotely serious about urban, just invest in the generator - you will be glad you did.
**This post was edited on Sep 14th 2017 at 4:57:33pm