Create a new folder named "Profile0" in the "\codemasters\perimeter\resource\saves\" directory. Use a text editor to create a file named "data" in the "Profile0" folder. Enter the following lines in the "data" file. Save the file and start the game to have all missions in campaign mode unlocked.
If you run out of energy when you really need it in a skirmish, save the game then exit back to the main menu. Go back into your saved games and load your skirmish. Your energy supply should now be 10,000, like it was at the start of the game. You will not do not lose any other abilities or buildings.