Such infrastructure is costly to set up but, once in place, can allow ships to plug into power generated from renewable sources while berthing, saving on carbon emissions and significantly reducing noise from power generators onboard.
Initial indications are a new zone substation might be needed at Port Chalmers to create sufficient capacity.
Aurora asset management and planning general manager Glenn Coates said the lines company had undertaken a preliminary investigation to understand likely capacity and configuration requirements in the long term.
The company has a 33/11kV zone substation in Church St, Port Chalmers.
"While this is relatively close to the port, our research concludes that the most practical and cost-effective solution to deliver the increased capacity requirement would be to locate a new zone substation as close as practical to ship mooring," Mr Coates said.
Port Otago chief executive Kevin Winders said when ships berthed, some of their engines or generators continued to run while in port for such things as lighting, heating, cooling, food storage and communications.
The noise from these generators has long been a source of complaints from the Port Chalmers community.
"If they’re running on shore power, they don’t need to run a big generator or engine, so clearly, all noise from the vessel stops — apart from the usual noise from excited cruise ship passengers being in our town."
Increasingly, cruise ships have been fitted with capability to plug into shore-power systems, where they exist, and Otago attracted more than 100 cruise ship visits last summer.
"Having ships on on-shore power is the ultimate outcome for our community.
"But the economics are pretty challenging at the moment, and we’re going to have to look at that over time and make investment when it’s appropriate," Mr Winders said
He said Port Otago leaders were excited about the proposal and were paying close attention to a shore-power project being introduced in Sydney.
"The port in Sydney has got shore-power going into White Bay and should go live in September or October next year.
"That will be the first electrified port in our part of the world, so it will provide a great opportunity to learn what they’ve done and see how they’ve handled the on-port component.
"The on-port component is quite straight-forward, I think. It’s the providing enough capacity on the network from Aurora to get it to port, and finding the right economics around that is quite challenging."
A Ports of Auckland feasibility study in 2017 estimated the cost of introducing shore power there would be in the order of $18.3 million.
Aurora signalled one design issue to consider at Port Chalmers is security of supply.
"The network and infrastructure upgrade costs could be reduced if security and resilience is provided by reverting back to ship generation if a rare fault were to occur on the network or shore-power equipment, thereby avoiding the need for backup supply assets," Mr Coates said.
New Zealand’s power network operates at 50 hertz, but some countries run at 60 hertz, so a frequency converter would be needed for any 60 hertz ships.
Aurora is due to replace some ageing infrastructure at the Port Chalmers substation in the next few years. This is not expected to affect shore-power requirements at the port.
However, a 33kV offtake area would probably be needed at the substation to accommodate shore power for marine vessels, Mr Coates said.
"A possible upgrade to the incoming 33kV lines will also need to be considered."
