Destroying all of the enemy Turrets in every map will allow enemy Awesomenauts to attack the Solar Drill from the back, as the Energy Wall protecting it will be gone.
Energy walls by map
Behind the outer turrets of the top lane. These allow a safer route in and out of the jungle area for allies, while denying opponents access to the area between the top turrets. It is deactivated after the top Turret is destroyed.
Behind each jungle area. These allow allies to access the jungle from the base and vice-versa, also creating a nice opportunity to drop in front of the top Turret (and possibly surprising enemies there). It is deactivated after the inner turret is destroyed, allowing enemies to enter the base from above.
On the side entrances to the jungle area. These provide a quick route into the jungle without having to rely on the anti-gravity field. Falls along with the outer turret, allowing enemies a path to attack the remaining turrets from above.
Sets of three Energy Walls for each team. Two behind each outer turret and one protecting the middle lane entrance. These allow quick access to the middle jungle area as well as nearby hidden areas for ambushes. The former are deactivated when their respective turrets (top and bottom) are destroyed, while taking out both inner turrets disables the latter.