The rail facilities in Lyttleton and Wellington will be significantly upgraded by the time the new ferries come.
Additional power generation is already in existence, once Tiwai Point is shut down in 2024 the Manapouri power station will be able to send it's power North, at the moment it's constrained by the transmission lines in the lower South Island. The Clutha Upper Waitaki Lines Project (CULWP) is under construction as of September 2021 to relieve this constraint, allowing an extra 400 megawatts to be sent north.
The next big project which will guarantee our energy demands for the future is the Lake Onslow pumped storage scheme,
It would, in effect, turn the South Island rock basin into a massive 5000 gigawatt rechargeable battery to power the country during periods of little rainfall or wind, ending its dependence on gas and coal generation.
When Lake Taupo pops we will have more to worry about than shipping goods around NZ.
The ferries don't go to Lyttelton and haven't done so since the early 1970s.
Pray tell how is the generation capacity of the Manapouri Scheme going to be sent north. It's not even connected to the national grid and in order for it to be, new transmission lines have to be installed between West Arm and the nearest point to the high voltage entrance to the national grid which would either be at Clyde or Roxburgh.
The pumped hydro at Lake Onslow is a pollies wet dream at the moment. The jury is out on the feasibility and efficiency of it. As to the claims about it turning into a large battery that will only work for so long because the Clutha River is a glacial fed river, like most of the large rivers in the South Island, and the glaciers in the South Island are gradually disappearing. 10 years ago there were 3200 odd ice glaciers and one rock glacier. Now I would strongly suspect that a few of the ice glaciers have become rock glaciers.
The South Island cryosphere accounts for a significant amount of the island's water storage capacity. Once that is gone, no spring thaw and our big east coast will become creeks except in significant rain events. So your pumped hydro is going to be a fizzler because you won't even be able to replace the water lost to evaporation. And that recharge capability is a very important point not just for this particular case but also for all of the acquifers across the island.
The precipitation will change and not for the better. The climate will become more dynamic and volatile meaning more winds and storms, higher temperatures, and less mean annual precipitation. And the precipitation won't happen as often, but when it does it will be in storms and heavy. The high incidences of wind and higher mean annual air temperature means that evaporation will increase, and that's higher water loss from water storage.
I am looking at the long term and I know some of the science WRT to the South Island climate and cryosphere. It is a particular interest of mine.
The Onslow project is of particular interest for me...the other half is from Millers Flat, down in the valley adjacent to the Lake... had many a trout fishing and/or boating trip up to Lake Onslow. I've known it to be 29 degrees (celsius) in the valley & a miserly 5 degrees (not allowing for wind chill either) at the lake!
One thing that I haven't seen in any detail about this project though is presumably they will send the water down to Roxburgh hydro for generation, being by far the closest existing generation plant...however it's an old dam & plant and Lake Roxburgh is AFAIK known to be heavily silted to the point it has far less capacity than it did 30 years ago... so presumably there's going to need to be a huge $$$Bn investment in the Roxburgh Hydro station & Lake.
Used to be a good pub at Millers Flat. That and the Raes Junction pub could mean a wobbly trip home.
The silting of the Roxburgh dam is an issue, I would suggest. The Clutha is the fastest flowing, most dangerous, and deadliest river in NZ. Right from when we were kids dad told us that if we ended up in there we would die, and we came from Eastern Southland, but we used to go up that way quite often. Because of its high flow rate, it would have a high sediment load capacity. Don't forget that it drains two lakes, Wakatipu via the Kawerau River and Wanaka with the confluence of the two rivers at Cromwell where Lake Dunstan is now.
Since the construction of the Clyde dam, theoretically the sediment supply between Clyde and the Roxburgh dam will be signed reduced. They could dredge the sediment from the dam back and that would help. Also don't forget that there is now a reduced water flow from below the Clyde dam because the flow of water through the dam is now controlled. Much like the dams of the Waitaki power scheme, because their water supply is controlled from Lakes Tekapo and Pukaki.
