(Re-posted and bumped from 2021 because of this new report on NZ becoming fully electrified in order to eliminate using fossil fuels)
Mike Kelly did the report. He’s a Professor of Engineering and his estimate is that the electricity sector would need to grow from 155 PJ to 425 PJ. That agrees pretty well with my estimate originally done in 2021 of going from the current production of 160PJ to 542PJ (see below).
I didn’t estimate the cost though whereas he did, plus other requirments:
“The cost to 2050 will comfortably exceed $550 billion, a workforce comparable in size to the health sector will be required for 30 years, including a doubling of the present number of electrical engineers, and it will need about 10% of the global annual production of lithium, cobalt, neodymium and other materials. On the manpower front, New Zealand will have to rely on the domestic workforce, as I assume that every other country in the world is working towards the same target. If they were not all so working elsewhere, the value of the New Zealand specific target is moot.”
BTW, when we don’t reach our Paris Accord targets in the next few years we’re going to have fork over some $20 billion to nations that have carbon credits.
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After a recent power blackout, which did not affect me, I took a look at Peter Creswell’s long-time blog, Not PC, for his take on the situation.
It turned out that he had nothing new to add to warnings he’d made years, even decades, ago:
if I may continue a well-worn theme of previous posts over several years (No Power; No power, again; Still No Power; ‘More power!’ says India. ‘No power,’ says NZ; Power outrage ) and remind you of several famous power outages (such as Auckland 1998, 2006, 2009 … ) this news and that conclusion above simply confirms what should have been obvious years ago: in this country the lifeblood of production, energy, is running out. Not because New Zealand is short of resources with which to produce energy. But because politicians and earth-first worshippers have declared we are not allowed to use them.
That’s from 2012, although he did include this recent comment from one Hamish Rutherford.
“Between the decision to rip up the rules on the gas market, to the difficulty consenting renewables projects, to the threat to build hydro storage at Lake Onslow, the market is simply responding to the signals that the Government is sending it.”
Running through his old posts the most detailed was Meet the Enfeebled, which had lots of graphs on power production, like this one:
... over the years from from 1980 to 1998, the growth in New Zealand’s generating capacity matched the growth in demand, growing at an averaged rate of about 150MW per year. Despite this, regular power shortages such as the famous outages of 1992 showed that even at this time capacity was near its limits — partly because of the lack of backup generation for the occasionally fickle hydro generators.
The basic thrust of the article was that since the turn of the Millennium (up to 2008 when the post was written) production growth had not matched consumption growth. You can read the detail of power stations built and closed:
TOTAL NEW CAPACITY 1993 – 2008: 1850.5 MW .
TOTAL DECOMISSIONED 1990-2008: 1333 MW
TOTAL NETT NEW CAPACITY SINCE 1990: 949.5 MW
This while consumption grew by 2700MW. The margin was growing thin. But what’s happened since the mid-2000’s? This from the MBIE:
Luckily the consumption has also plateaued at the same time to roughly the same level: 42,000GWh vs 44,000GWh production.
That is likely due to the steady conversion to energy saving devices such as LED bulbs and heat pumps, as well as the steady increase in insulated houses. But there will come a point where even slow economic growth of 2-3% per year will eventually outpace the improvements in energy efficiency.
But the greatest increase will come with the flip side of the renewable energy push: the electrification of everything. Below are the NZ consumption figures for 2018 in Petajoules (source MBIE report. pdf pages 14-15):
The supply figures are a little different, since we have to import most of our oil while we produce more than we consume for coal (38 vs. 25) and gas (172 vs. 74).
Current total electricity production from all sources in NZ is about 160PJ. So we’re talking about more than doubling our electrical production, and some 84% of it already comes from renewable sources. Geothermal has grown tremendously since 2005 but there are limits being approached quickly. Hydro reached its limits years ago; there have been more cancelled hydro projects to add to Not PC’s 2008 list – and most of those have been due to the Resource Management Act and the Environment Court
So that leaves Wind and Solar, which means an even greater increase needed from that slim red line below.
Basically from 8Pj to more than 300Pj – an increase of 3,750%.
I’m being generous in allowing that the remaining 82PJ might come from a mix of new hydro and geothermal, with a slight assist from residential PV (solar panels).
Moreover that’s just to replace current fossil fuel energy consumption.
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Rather than looking at Petajoules which involve efficiency conversion assumptions, commentator Chris Morris suggests simply looking at TWh.
The ballpark number to electrify NZs energy demand (with a lot of assumptions) are about a doubling of the grid so 90TWhpa. Here is a 2019 MBIE analysis of it, Electricity demand and generation scenarios. Notice how they claim cost of renewables is cheaper – it isn’t as there is no cost for integration into the grid. Market distortion by credits also there. And if it was cheaper, it wouldn’t need subsidies.
Finally it must be noted that since Wind (and solar) are unreliable, tanking to zero on a regular basis, they will need backup generating capacity – 300Pj of it. Where will that come from? A doubling of hydro/geothermal power? In the case of Hydro it has problems itself, though nowhere near as bad as Wind, but Huntly was built to back them up in drought years.
To paraphrase Sir Humphrey, these are heroic assumptions.
There is one other possibility that should not be dismissed, even as crazy as it may sound. I’m not talking about Thorium Molten Salt Reactors, Fusion reactors or nuclear power in general on the supply side.
No, I’m talking about crushing the demand side. A policy of Zero Economic Growth, or even negative economic as all that fossil fuel energy is shut down to enable a Zero Carbon nation. Look how happy many Greens are with what Covid-19 has delivered to Fortress NZ: the huge reduction in airline flights to and from the nation and the subsequent massive drop in tourism and internal travel in general.
After all, as Robert Bidinotto explains:
Typically, the person who calls himself an “environmentalist” is really just a nature-loving “conservationist.” Appreciating the earth’s natural beauty and bounty, he is understandably concerned about trash, noise, pollution, and poisons. Still, he sees the earth and its bounty as resources–resources for intelligent human use, development, and enjoyment. At root, then, his concern for the earth is human-centered: he believes that this is our environment, to be used by people to enhance their lives, well-being, and happiness.
But the leaders of the organized environmentalist movement have a very different attitude and agenda.
Their basic premise is that human activities to develop natural resources constitute a desecration of nature–that, in fact, nature exists for its own sake, not for human use and enjoyment. By their theory of ecology, they see man not as the crowning glory of nature, nor even as just another part of “the web of life”–but rather as a blight upon the earth, as the enemy of the natural world. And they see man’s works as a growing menace to all that exists.
See also
Where does our energy come from? (NZ)
42 Inconvenient Truths on the “New Energy Economy”
Net Zero for New Zealand
No Minister 
The same comment applies here as I put in the other post. Best to have all discussion about electricity generation in GWh rather the PJ. The thermal efficiency of a lot of the GTs and coal fired plants drops a lot when at part load. They also use a lot of fuel just starting before they can generate. The energy and power demands are two separate issues that are only partially linked. Many commentators do not differentiate – proof they didn’t get School C physics.
The big problem in NZ is our power ramps up about 2000MW between 5am and 7-8am most mornings year round. The hydros like Benmore and most of the Waikato do most of this, but the thermals do maybe 500MW, depending on what is running. Get rid of the latter, and where will the ramp up come from? Sort of a duck curve at other end of day.
Any one who tells you there is a simple (and not prohibitively expensive) solution that doesn’t mean curtailment can be ignored as they don’t know what they are talking about.
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Okay. What about the basic comparison of the PJ numbers for an all-electric or near all-electric change from fossil fuel consumption?
PJ assumes a conversion efficiency. At 100% 1PJ is 278GWh. The coal figure looks like it includes the coal burned at all the Fonterra plant where the efficiency is maybe 80%. At the Fonterra sites, the coal power is used to provide process steam. A coal fired boiler does that pretty efficiently – that is where the 80% comes from.
The government’s commitment to Net Zero is best summed up as unicorn farming, which is easy for them to do. You make a law that unicorns must be produced in large numbers at a set date (let’s say 2035). You buy lots of land to put the farms on. You clear the trees. You build a fence around the farms. You buy farm machinery, make barns and feed silos, employ people and train them up. Everything goes very well, right up to the point when the unicorns are supposed to arrive.”
Unfortunately, there are many in government who believe you can use legislation to overcome the laws of physics. It may come as a shock to some, but you can’t.
Going to update this post with these two items but putting this here just in case.
– Where does our energy come from
– 42 Inconvenient Truths on the “New Energy Economy”
Things do come back from the dead.
What I wrote then is still valid, even more so. Wind has got more expensive. Data from the US and UK indicate that the firming cost of the unreliable – replacement generation for when they can’t provide, makes wind and solar about three times the cost of natural gas fired plant.