But it’s not always the cheapest – just ask the team behind the proposed gas terminal at Port Kembla.

Australian Industrial Energy (AIE) is looking to install a floating gas terminal at a berth near the coal loader at Port Kembla.

Called a Floating Storage and Regasification Unit (FSRU), the vessel will remain docked at the berth.

READ MORE: Govt backs Port Kembla’s $300 million gas terminal

Liquefied natural gas (LNG) tankers will pull up alongside the FSRI and transfer their contents into it.

From there it will enter an underground pipeline that will link up to a spur of the Eastern Gas Pipeline at Cringila, on the northern side of Five Islands Road.

AIE has a preference for the longest of three potential pipeline routes – one that takes an 11-kilometre trip around the port to the north and the south alongside Springhill Road.

The other two routes are kilometres shorter – especially the one that travels in a straight line to Cringila – but they’re also much, much more expensive.

That’s because they involve laying pipe underneath the harbour.

“Trying to drill under the harbour, technically that’s quite challenging,” said AIE’s CEO James Baulderstone.

READ MORE: Offshore storage plan for gas terminal

“You’ve got a lot of subsurface rock to deal with, you’ve got to work out how to string the pipeline at each end and pull the pipe through.

“It’s a heavily industrialised port so there’s not a lot of spare land at either end of that drilling location.”

There is also the issue of affecting the harbour operations during the drilling as well as impinging on BlueScope’s operations wherever the pipeline would surface on the other side.

Heading north around the port largely removed the need to drill underground tunnels – except for where it crosses road and rail tracks within the port.

“When you’re going around the north you’re just doing a normal trench, you’re not having to do a tunnel exercise,” Mr Baulderstone said.

“With a normal trench you can place the pipe in piece by piece, weld it and go to the next point.”

Mr Baulderstone said none of the three route options would travel under residential houses.

The terminal is yet to be approved by the NSW Government but has been declared “Critical State Significant Infrastructure”.

He said AIE was hoping for an approval early next year and said the terminal and pipeline would be constructed at the same time.

“We’re looking at about a 12-month construction time for both the berth and pipeline route,” he said.

“If  we get approval in February next year, we’ll be looking at having the facility operational by the first quarter of 2020.”