Are you talking with regards to domestic (home) gas use or power...

Are you talking with regards to domestic (home) gas use or power generation? Because Townsville doesn't have a connection to the NQGP (in fact I'm pretty sure Townsville doesn't even have piped gas), and increased power consumption in a residential area doesn't impact local generation (i.e. Stanwell doesn't work harder if Rocky has a hot night), the grid is connected along the entire East coast.

Townsville only uses about 2575MWh/day of electricity, so that's about 107MW/hr. Domestic consumption isn't that significant it's industrial loads that drive growth. With regards to future expansion, Genex's Kidston pumped hydro is enough to power Townsville on its own, without the substantial RE projects under way there too (Copper string, Majors creek, Ganymirra, Ross River, Nebo...).