Adds massive cargo ships to the game, that function similarly to trains. Also adds deep sea oil, oil platforms, tanker ships, train bridges and other water based content.
If you hook up your oil rigs to your main power grid you get and infinite amount of power for free. The oil rigs don't need to be hooked up to your main power grid but if you want to use modules in the oil rigs you need to give them more power and if you hook them up to your main grid you have unlimited power.
Is this a bug or intentional?
Sorta both a bug and intentional. It is getting properly fixed in the next update :)
For now, don’t put substations next to oil
rigs. You shouldn’t have to give more power if using modules though - that’s what the ‘infinite’ power source is for.
Release 0.2.3 adds a setting for the oil rig onboard generator. When set to "infinite", it will no longer connect to the power grid so no more free grid power.