Shoving stack size

How many BB would u need to open shove as opposed to doing a normal raise? 10-15? 10 or less?

Yeah, something like that.
It depends.

Hmmm, like asking "when is a tomato too expensive?"

You need to know availability, season, crop production, quality, competition prices, consumer demand..............................

Or "How much money do I need for a vacation?"

Where are you going, where are you starting, how long will you stay, do you have a job, how many people are going with you, what luxury level do you want to enjoy..............

Are you open shoving 27o 9 handed UTG with 30 BB (OK I know, but to make my point) or Q9o from HJ 5 handed with 6 BB? Are you shoving over the top or as first in? Are your players that you are shoving on passive, loose, tight, aggressive, combinations thereof???

Some stacks of 20 BB can be open shoved, depending, some stacks of 5 BB should be folded depending..

Take some situations and post hand histories, that will be the best way, since the answer to your OP is "it depends"

depends on position, players your against etc, but if you have low bb and good cards to shove with than go for it, otherwise it depends on the table you're at

This is exactly right ... Depending...
IMO, if you have any less than 8 Big Blinds, its shove/fold.
Maybe even with 10/12 bb, this is still worth while, but if you still have 15 bb left, there is still plenty of time to move.

AS fletchdad said it depends on many variables: position, stacks, stage, and so on.

Maybe as a "rule" u could follow next, with 10 BBs left shove hands from middle to late position. Hands like suited connectors or better.
With 5-10 BBs left shove nearly everyhand from late with no raises preflop.
With 5 BBs left, well.... here we go

Very much dependent on villains and table dynamics, but you should almost certainly be shoving in the 10-15 BB range and there can be situations where even shoving up to 20 BBs can be fine, although with a stack like that I'm much more apt to be looking for resteal opptys than open shove spots.