Opinion: A science illusion is when some aspect of the basics gets lost or is uncritically reported. This was seen in a recent radio interview with a representative of LanzaTech. That company has developed a multi-step process to create a sustainable ethanol using captured industrial carbon dioxide emissions from burning coal or fossil gas.
This appears green at first. However, shifting fossil carbon atoms into ethanol is no different to the fossil ethanol derived from petroleum. In both cases, the fossil carbon gets into the atmosphere sooner or later. That is, when the ethanol is either burned for fuel or when its derived products like polyester decay away. The LanzaTech ethanol product is therefore certainly not the “sustainable ethanol” that was claimed in the interview.
A science illusion in a political context is the “doubling of renewable electricity” policy of the Government. Again, a false green impression is given because the new renewables will be mostly composed of highly intermittent wind and solar. Doubling the number of wind farms will not help when the wind falls away for a week or so in a dry winter. At such times, a future fully electrified New Zealand will require burning even more coal or gas to keep the lights on.
The effect is starting to be evident even now with the hydro lakes just a little below normal. You might have gone for an Easter holiday in a grid-charged EV. If so, you were driving a hybrid that was powered for a fifth of the time by a virtual second engine using a mix of coal and fossil gas. The current extent to which fossil carbon is used for electricity generation can be seen at the Transpower site here.
Perhaps the strangest example of a science illusion in recent years is the supposed additional value of a major green hydrogen plant in Southland to be an aid for dealing with dry years. The idea seems plausible at first glance. Hydrogen production is reduced or shut down when the hydro lakes get low. This means more power available for the grid.
However, a problem can be seen by way of using a simple analogy. We start with a conceptual large water tank – that’s all the hydro lakes together. The tank has a hole at the bottom through which water drains out at a roughly constant rate – that’s all the water used for hydro power generation. There is water flowing into the tank also at a roughly constant rate – that’s the collective river inflows into all the hydro lakes.
Sometimes, however, the inflow to the tank declines considerably and its water level goes down – that’s the impact of a dry year.
The extra power required by the large hydrogen plant is equivalent to putting a second hole at the base of the tank. This means the tank water level goes down faster. Putting a plug in the hole when the water level gets low is not going to be of much help because it won’t increase the rate of inflow. There is also not much water left by then for power generation.
The giant hydrogen plant would only make the dry year risk greater. Put simply, you don’t conserve water in a leaky tank by putting another hole in it.
The unusual nature of the hydrogen dry year proposal prompts thoughts about motivation. A possibility is that the major electricity generators that proposed the plant were also concerned about cheaper power in winters and dry years from the Lake Onslow pumped storage scheme. If that was the case, the hydrogen dry year aspect was a diversion to implant the idea that the Onslow scheme might not be needed.
Whether the Lake Onslow scheme is considered for further business case investigation will depend on the energy policies of political parties going into the 2026 election. It will be interesting to see if the giant Southland hydrogen plant makes another appearance before then.
Finally, we can consider the potential of an illusionary aspect to the basic climate goal of net zero carbon by 2050, defined as achieving a balance between carbon dioxide entering and leaving the atmosphere.
Using this strict definition, there are two possible paths.
Path 1 is what everyone thinks of – the progressive reduction of a nation’s carbon dioxide output until its atmosphere balance is achieved by 2050.
Unfortunately, there is also a Path 2 where reference to net zero carbon becomes illusionary in a sense. This happens if a selfish nation maximises its cash gains by burning fossil carbon at a rapid rate and then stops before January 1, 2050. They can then state that they have achieved their promised goal of net zero carbon by 2050. Of course, if every nation did that then large parts of the planet would be unliveable by then.
Each nation will have its own trajectory to 2050 that lies somewhere between the two paths, hopefully more toward Path 1. However, the New Zealand Government’s commitment to possible new coal developments and expanded offshore gas exploration suggests a policy more weighted toward Path 2.
Perhaps that is what National had in mind during the election when noting that their climate change policy was to approach emission reduction very differently to Labour and the Greens.
To conclude, keep an eye out for science illusions because there’s bound to be a new one coming soon. You don’t have to be a rocket scientist. Just take time to be critical and break the idea down to its simplest form.
When I first heard of pumped hydro I immediately had one question:
Surely it takes more energy to pump the water back up the hill than can be mustered when it falls?
I expected this question to be answered within the first two paragraphs of any story on pumped hydro and I became increasingly worried when it never was.
Then in the footnotes of one story there was a reference that said pumped hydro could be expected to be 80% efficient. This sounded good, until I read further that “80% efficient” apparently meant that if it required X cubic metres of water to fall to generate 1 MW of electricity, it required 1.25 MW to pump the X cubic metres back up.
If this is true, then isn’t this pumped hydro’s equivalent to the wind-not-blowing, sun-not-shining or snow/rain-not-falling? And I guess could be called a “science illusion”?
Yes of course you get less energy out than you put in, same with a battery. The point is that when you have a surplus of solar and wind you can shut the windmills down and turn the panels off or you can store the energy but pumping water up hill for when the sun isn’t shining or the wind isn’t blowing. The cost of the energy at times of surplus like this is almost zero, but the cost of energy at times of deficet is quite high so it can be cost effective.
Peter
Thank you very much for that explanation – every pumped hydro story should start with that.
So pumped hydro starts with 100% capacity at the Top (the battery – which I will guess cannot be increased above 100% – due to no room & nowhere to pipe it from) and a potential capacity at the Bottom (I will guess somewhat less than 100% due to lack of room) – with the difference being the Max usable capacity.
In order to use any of the Max usable capacity, 1.25 times the power generated is required from (existing) cheap sources to replenish the Top. And the pumped hydro system is then not constrained by other factors beyond the owner’s control. Interesting.
As for biofuel, surely the media should only allow the name “biofuel” to be used for recycled-carbon fuels, anything derived from fossil fuels should be called oil, or coal-derivative or simply fossil-fuel.
Earl I think this is a better site to see our hourly electricity production (and most other countries in the world. You can see from this that NZ is unusual in that gas and coal don’t do any or much peaking here in NZ but run continuously right through the night – its the hydro power stations that are doing the peaking. It appears that the way our electricity pricing system is set up, where the half hourly price paid to all generators is the highest price of the last bit of generation needed for that half hour, means that its in the interest of the electricity generators to always have some gas or coal in the mix so they get high prices for their cheap to produce power.
But I completely agree with you that just more wind and solar is not NZs solution. Rather than your Onslow scheme wouldn’t it be substantially cheaper to set a number of existing hydros up to be pumped hydro schemes – pumping water back up to the lake above in times of high wind and solar generation and also being able to run them harder (with additional turbines) when there is cloudy still weather? (including the Tekapo- Pukaki twin – pumping from lake Pukaki up the canal, running water back up the canal to teacup and pumping back up into Tekapo. I guess that would mean living with greater fluctuations in the level of Tekapo)
Thanks for the link Peter. I was looking more into the future because we are building more wind and solar but very little in the way of firming. In time, hydro by itself will not be enough for fast response needs and so, on present policies, that will have to come from fossil sources. This aspect has been lost in the “doubling renewables” announcements.
With respect to your pumped storage queries, the NZ Battery investigations identified Lake Onslow as the only viable large-storage option for dry year pumped storage, with capability for months of generation at 1000 MW if needed (5 TWh of energy storage capacity). That 1000 MW would also be used as fast response, so Onslow would serve multiple purposes. However, the scheme is expensive at $16b construction cost. Unfortunately, the government stopped the business case report being completed so we don’t as yet have a corresponding quantification of its multi-use benefits over a 100-year lifetime.
If fast response by itself was the main concern then multiple small schemes would be more economic, as you note. I don’t think though that there are any schemes in the world that operate by running a hydro dam cascade backwards at times. Tekapo / Pukaki might be a fast response option if Genesis found it economic and feasible to convert their Tekapo A and B stations to pump/generation. Tekapo couldn’t be used for dry years though because it’s a scenic lake and the water level variation would be significant, impacting Tekapo village. Also, low-price power for pumping is likely to coincide with times of already existing high lake levels because of high inflows from the Godley River.
Another problem with converting existing hydro dam’s to pumped storage. Most of the South Islands existing hydro dam’s are very poor at storing water year to year.
Almost all of them have consent conditions requiring minimum discharges to provide downstream drinking water, irrigation & ensure river ecosystems survive.
When faced with dead pool (dam’s getting too low to operate) they are legally required to prioritise drinking water & irrigation over electricity production.
Swapping that around means farmers culling herds and councils rationing supply.
All that comes from almost all of the dam’s not being designed for pumped hydro and their consenting (based on the design) also not being designed for it.
Vs Onslow from idea, though design and eventually consenting is just designed to store vast amounts of energy via hydro head.
I feel the single biggest problem with Onslow, the kiwis who will benefit most have not yet been born. Onslow has a very high CapX cost that would have to be born by the Crown, with by far the single largest benefits going to unborn and young kiwis.
NZ isn’t good at making investments that favor young or unborn generations.
We prefer quick and immediate payback within one or two election cycles.
That may change as new generations of voters begin to make up the majority of the electorate.
https://app.electricitymaps.com/zone/NZ?solar=false&remote=true&wind=true
Electricity maps was the site that didn’t come out in comment above