Police Station is a special Building which generates Boost. The specific Boost it produces is Dynamite. Boost is created after a fixed time interval continuously as long as you collect it after generation, hence a good constant supply of Boost. Note that you cannot collect them when your Boost is at maximum, so you need to use some before collecting again.
Plants vs Zombies Adventures Police Station – All stats
All the stat of Plants vs Zombies Adventures Police Station including level upgrade, number of Boost, Boost generation time and build time are shown in the table below:
Plants vs Zombies Adventures Police Station stats
||Number of Boost
For a complete guide on PvZ Adventures Beta, go here.