I personally use it mainly on:
Raven's End – I always take T2 straight away to build it since one Juice Tank covers 6 power wells - and looking at the other team, their wells drains much earlier than us.
Into the Jungle – Power wells are sparse, and I almost always struggle with power.
Unexpected Visitors – Same as Into the Jungle.
Slave Master – Same as Into the Jungle.
But yeah, on most other maps, its use is very limited, so I wouldn’t be against a change or rework.
Also, I'd like to think it’s an amazing combo with Resource Booster, but I’ve never done the math, so it’s just me believing it’s worth it (and maybe it’s not).