Steps:

Go to Cityville 2
Open Cheat Engine
Select -plugin_container.exe(firefox) or FlashPlayerPlugin_11
Value Type '4 Bytes' to 'double'
Scan your current amount of energy Ex. 25
Use 1 Energy
Next Scan 24
Click the 1st address, Hold Shift and then click the last address.
Click on the red arrow.
Change all the values to any amount that you want ex. 100 (TIPS: Select 1 address below. Hold Ctrl +A and then hit Enter key)
Use some energy and then reload the game.
HAVE FUN!!