Submitted to the Marlborough Express to be published with Climate Action Week, February 2024
Tom Powell & Bill McEwan The Marlborough Sounds is getting warmer; that is the conclusion of 8 years monitoring by the District Council. Last summer was the warmest yet in the sounds, with peak water temperatures over 20⁰C. Swimmers this summer will rejoice at the warmer water. For marine life, it is a different story. Water temperature has a major impact on sea life. Just as on land, plants and animals adapt to the temperature range of their environment. Change that range and the whole marine neighbourhood changes. One important aspect is the amount of oxygen the water holds. We all breathe oxygen and sea life do too, catching it in their gills. Unfortunately, though, for sea creatures, the amount of dissolved oxygen that seawater holds goes down with increasing temperature. So, sea life now have to “breathe” harder to get the oxygen they need. It is similar what people experience tramping at high altitude. Fish can adjust to higher temperature by moving to deeper, cooler water or by leaving the sounds entirely. Sea creatures like shellfish and sponges don’t have that option. Other aspects of the marine neighbourhood also change. Kelp and sponges, which are a food source for other organisms, tend to thrive in a narrow temperature range. Change the water temperature and many species of kelp and sponge disappear. If you are a fish depending on these organisms for food, the supermarket shelves are now getting emptier; another reason to move out if you can. Some foreign marine organisms thrive in warmer waters and these will become sounds sea life’s new neighbours. Like new neighbours everywhere, some will fit in and some won’t. New predators and marine diseases will arrive. Blooms of toxic algae will become more common. The new neighbourhood will be in a state of flux as temperatures continue to increase. Add to this other stressors humankind has put on the marine environment in the sounds: gradually acidifying seawater due to rising CO2 emissions, siltation due to logging and landslides on human-disturbed land, sea life caught and killed by commercial and recreational fishers, destruction of tube worm reefs by historic dredging, and all manner of rubbish and chemicals dumped into the water. So, when you take that refreshing swim in the sounds this summer, spare a thought about the plight of the sea creatures living just below your feet.
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Essay written for Climate Action Week but not submitted.
Tom Powell If we were paying attention, we‘d have seen it coming. It was as clear as the proverbial writing on the wall. The scientists have been warning us for decades now. But most of us have been too wrapped up in living our lives. Now it is here. And like the writing on the wall at Belshazzar’s feast, in the Biblical story of ancient Babylon, the message isn’t good. It is so random and unfair. Like the wrath of a clumsy demon. This home flooded but not that one. This home incinerated but not that one. This family’s livelihood destroyed but not that one. It is as if we are all walking through a minefield and a few get unlucky. In a sense, it has always been this way, with car accidents and disease ripping away loved ones at apparent random. There are more mines now, though, and while perhaps not always lethal, they nonetheless bring heartache. Which one of us will suffer the next flood or wildfire or other weather disaster that up-ends our lives? Our world has changed and none of us, civilised or wild, are prepared for it. Everything, from roads to ecosystems, have adapted to a different climate, one of the past. We now must adjust to a more violent and unpredictable world. We must try to navigate more landmines buried in the path ahead. How do we reconcile the unfairness of this calamity? Why should one family suffer while another remains safe? After all, it is we that are to blame. Some might resolve to live a simple, self-sufficient and low-emissions life, knowing that they, at least, provided little “fuel to the fire”. Others might throw up their hands and say there is nothing to be done – our calamity is written into our economic system; the need now is to protect ourselves and our loved ones as best we can. Still others will shout louder for the need to reform our ways, hoping that the powers that be will listen. We will never know whether Balshazzar might have been saved had he heeded the message on his palace wall. All we know is that he didn’t and he was ruined. For us, there is still time, but the writing also tells us our time is running out. We must all do what we can in the time remaining. Submitted to Marlborough Express but not published.
Tom Powell I got an email through the Climate Karanga Marlborough website the other day. It read: “from Google: a 10kg dog would be the equivalent of 240kg of CO₂ emissions per year. In response to the Stuff article showing a photo of two people and a dog” The photo was of me, my partner and our dog, and accompanied an article I’d written for the Marlborough Express. For context, 240kg CO2 is about the emissions from two tanks of petrol in a small car. The intent of the email was clear: I was someone who claims to be a climate activist but who owns an emissions-generating plaything. I was being seen as a hypocrite! It got me thinking about the bigger picture. Climate sceptics accuse us of being hypocrites when we don’t “walk the talk” and we accuse them of wantonly spewing CO2 into the atmosphere for continuing to live an emissions-intensive lifestyle. You’ve all heard of “flight-shaming”, I presume. But, does this tit-for-tat battle get us anywhere? Climate scientist Michael Mann argues the polluting companies have traditionally focused on the role of personal responsibility when addressing pollution, so as to keep the focus away from themselves. As long as we are pointing the finger at each other, we aren’t pointing the finger at the real source of the problem. There is a bigger issue here, however, when thinking about the weather disasters we can expect with continued global warming. Some years ago I was working in The Philippines where I met a woman who told me of a family member who was stealing from other family members. I suggested she might want to kick that person out of the family. She said, “oh no, you can’t do that! You never know when you might need their help when the next typhoon comes!” You see, The Philippines is a country that experiences regular disasters – earthquakes, volcanic eruptions and typhoons - essentially cyclones like the ones we get here, but much more frequent. They’ve learned that they need one another to get through these disasters. There is a lesson here. In order to best get through the turbulent times ahead, we need to stick together. I was out in the Sounds when the July 17th, 2021, weather bomb hit. The road was flooded in one direction and blocked by a slip in the other. The power, telephone and internet were all out. Blocked drains and raging streams were tearing the place apart. It was a scary scene! Thankfully, it wasn’t long before neighbours appeared. Diggers were out clearing the slips and people were up our driveway checking to make sure we were OK. It was a wonderful relief and I was very grateful we were all on the same team. Individual lifestyle changes, while helpful and welcome, aren’t going to be enough to solve the climate crisis. Surveys show that climate ranks third among most people’s concerns, behind cost-of-living and healthcare. Not everyone is ready to transition to a low-emissions lifestyle just yet. So, I would urge you to forgive the emissions of those around you. You just might need their help when the next weather bomb hits. What will make a difference is collective action – government action. It will be through government regulation, policies and legislation that we will find the fairest way to share the burden of the transition to a low emissions economy. The best thing you can do right now to arrest our steadily deteriorating climate is to vote for climate action. Study the different political party’s policies and proposals, and vote for the ones who promise to continue to cut our greenhouse gas emissions. Our children and their children will thank us for it. submitted and published in the Marlborough Express
Tom Powell It seems every day there is a new technology announced that will help us in the fight against global warming. These stories spark our imagination and give us hope. But as time has gone on, we sadly learn that each basket of new technology contains fishhooks – unexpected problems and side-effects. Sometimes we only find these fishhooks when we dig really deep into a promising basket, which makes them all the more disappointing when we find them. Electric cars are a good example. They give us almost all the convenience of the petrol cars we’ve come to know and love. But, as we’ve come to learn, the minerals used in the batteries come at an environmental and human cost - child labour in the Democratic Republic of the Congo to mine the cobalt for the batteries. Sure, we can avoid the greenhouse gas emissions of petrol vehicles, but there is still an environmental and social cost. It is a painful trade-off. The latest example of a promising new technology is green hydrogen. It is a highly energetic fuel that can be created from nothing more than electricity and water and when passed through a fuel cell to create electricity, makes only water again. Finally, we think, a clean and easily created fuel that can power our trucks, ships and planes! Yet, just as our government is approving a $100 million subsidy for green hydrogen development over the next 10 years, we come to find some fishhooks. It turns out, hydrogen is an intense but indirect greenhouse gas. Hydrogen released into the atmosphere readily reacts with hydroxyl radicals, short-lived gas molecules generated by sunlight. We depend upon those same hydroxyl radicals to remove methane and ozone from the atmosphere, both intense greenhouse gases. So, releasing hydrogen into the atmosphere, through leaks and upsets, will slow the natural removal of other harmful greenhouse gases, increasing global warming. The overall effect is still under study, but hydrogen is estimated to have a warming potential of approximately 100 times that of carbon dioxide over a 10 year period. And, hydrogen is a notorious leaker. Being a very small molecule, it leaks through nearly everything, including carbon steel and the high pressure carbon fibre tanks used for fuel storage and in hydrogen fuel cell vehicles. Engineering work on stemming those leaks has focused mainly on preventing leaked hydrogen from reaching flammable concentrations (i.e., more than 4% in air), but it is unlikely that we will be able to stop leaks altogether. It is estimated that 2.7% of global hydrogen production in 2020 leaked into the atmosphere. As hydrogen use becomes more widespread in the world economy and hydrogen production increases, The International Energy Agency estimates hydrogen leakage of between 2.9% and 5.6% by 2050. This amounts to nearly 30 million tonnes of hydrogen per year in the high-risk case. And then we find that transportation has the highest leakage rates, with fuel trucks and storage estimated to account for 5% leakage with another 2.3% coming from the actual hydrogen usage. So, here we face another painful trade-off, but in this case, it is trading one source of global warming for another. Do we risk prolonging the already intense warming of methane in the atmosphere (84 times the warming potential of CO2 over 20 years) in order to move people and goods with hydrogen fueled transport? In the end, there are no easy trade-offs. Our only really effective strategy is to stop – stop driving and flying as much, stop buying things from far flung places and stop trying to engineer our way into a low emissions lifestyle as convenient as the one we’ve enjoyed until now. The planet’s climate is changing and so must we. Submitted to Rural News
Tom Powell In a 1 August opinion article (Could the paradigm be shifting? (ruralnewsgroup.co.nz), Doug Edmeades reports on a seminar given by American physicist Tom Sheahen, who argues that the climate effect of the greenhouse gas methane is so small as to be irrelevant. It would be so easy if this were true, but, unfortunately, it isn’t. But I agree with Doug; a paradigm shift is under way, nonetheless. Sheahen quotes work by two climate scientists: William van Wijngaarden and William Happer. They’ve published a number of articles together and with others in peer-reviewed scientific journals. Their specialities are the optical properties of the atmosphere and computer modelling of those properties. The content of their peer-reviewed publications generally conforms with mainstream climate science. The article referenced by Sheahen is an un-peer-reviewed article titled “Methane and Climate” published in 2019 by an organisation called the CO2 Coalition. Their stated purpose: “The CO2 Coalition of climate scientists and energy economists informs the public (1) about the net beneficial impact of carbon dioxide emissions on the atmosphere, land and oceans, and (2) the net negative impact on the economy, living standards and life expectancy of reducing these emissions by restricting access to energy”. It is clear that this group has a scientific bias. The article claims that the present rate of warming by molecular methane is only 10% of that of molecular carbon dioxide, so why worry about it? This is the gist of Sheahen’s argument about methane. The fact that this article is not peer-reviewed is worrisome. Science is based upon repeatable experimentation and collective agreement. Work that does not have the stamp of approval from other scientists is not yet considered valid. This peer review process is in place to prevent fraud and it generally works pretty well. The history of science is full of examples where peer-review was not allowed to confirm important results, usually due to political interference, and whole disciplines of science have been led astray. Look up “Trofim Lysenko” for a good example of this. While van Wijngaarden and Happer’s conclusion about methane may be correct, there is no way to confirm it without peer review. I found one review; a 2019 E&E News article by Scott Waldman, reprinted in Science magazine. The article states, “The paper's claims largely have been known since the 1960s, said Andrew Dessler, a climate scientist at Texas A&M University who reviewed the research. He said the calculations appeared to be correct, but that they were presented in a misleading way.” So, how are they misleading? One obvious way is the omission of any mention of methane’s chemical interactions in the atmosphere, leading to tropospheric (lower atmosphere) ozone production and increased stratospheric water vapour – both intense greenhouse gases. This increases its warming effect. In addition, the near tripling of methane concentration in the atmosphere since pre-industrial times (729 parts per billion (ppb) in 1750 to 1866 ppb in 2019) has led to it accounting for 25% of the effective radiative forcing (warming) of carbon dioxide (IPCC AR6 WG1 2021, page 960). In a second opinion, the International Energy Agency has concluded that methane accounts for 30% of global warming to date (Global Methane Tracker 2022, IEA, Paris). But, let’s go back to the original claim; that methane’s contribution to global warming is too small to worry about. We need to consider the size of the global warming problem and the fairness in how we address it. The problem is huge and requires all hands to the pump. We don’t excuse Joe from helping because he is only one-tenth of the workforce. In terms of fairness, New Zealand businesses and councils face the higher cost of carbon dioxide and landfill methane emissions through the emissions trading scheme, so why should farming get a pass? I agree with Mr. Edmeades’s suggestion that the paradigm is shifting, however. While we’ve long seen government concern for farming’s greenhouse gases, we are now beginning to see similar concern from large overseas industry buyers. The food giant Nestle is leaning on Fonterra to lower the emissions on its milk products. The European Union is talking about applying “border adjustment mechanisms” (i.e., carbon tariffs) on importers who do not take steps to limit their greenhouse emissions. The paradigm is changing. Reducing greenhouse gas emissions isn’t just good for the planet, it is now becoming good for business too. Tom Powell is a retired geoscientist who writes on climate matters for the Marlborough Express. Tom Powell – Climate Karanga Marlborough
Tom is sitting at the kitchen table, looking over the news. He looks up as Marg comes into the room. Tom: “Marg, did you read about this American oil company that claims they emit no carbon? How can they say that? There must be heaps of carbon emissions in making petrol from oil and then getting it to us in those huge tankers” Marg: “I think they do it by offsetting.” Tom: “Offsetting? What’s that?” Marg: “Let’s ask Google, she’ll know. HEY GOOGLE, HOW DOES CARBON OFFSETTING WORK?” Google: “Companies can claim to offset their carbon emissions by paying to remove carbon from the air somewhere else or by preventing carbon from being emitted. If companies pay to remove or prevent as much carbon as they emit, then they can claim to be ‘carbon neutral’ or ‘zero emissions’. Most offsets are in forestry – either planting trees or protecting forests from deforestation.” Marg: “OK, I can understand offsets for planting trees since they soak up carbon from the air, but you mean companies can also buy offsets for protecting existing forests? How does that work? Google: “The company selling the offsets purchases the rights to a forest to protect it from being cut down. A certifying company agrees that the forest would be otherwise cleared and certifies that the carbon credits represented by the ‘avoided deforestation’ of forest are real. The offset company sells the credits and uses some of the money to protect and monitor the forest. The total credits are the amount of carbon that would be released if the forest were cleared.” Tom: “So, companies pay someone to not cut down a forest and then claim they’ve removed the carbon in that forest from the air? Sounds fishy to me.” Google: “The most common criticism of offsets, however, is that they allow companies to avoid reducing their actual greenhouse gas emissions, thus delaying action to cut greenhouse gas emissions and mitigate global warming. They spend money on carbon offsets when they should be spending money on reducing their actual emissions.” Marg: “I believe they call that ‘greenwashing’; claiming to do the right thing but actually just trying to look good to your customers.” Google: “These companies are also usually taking steps to measure and reduce their carbon emissions.” Tom: “So, I guess you are saying that the “zero emissions” claims may be a bit overblown, but these companies are still moving in the right direction. And, spending money to protect and grow forests is not a bad thing.” Google: “The days of companies claiming ‘net zero emissions’ through offsetting may soon be coming to an end, however. One of the outcomes of last year’s COP 27 climate meeting was the establishment of a new Climate Mitigation Contribution credit to replace these offsets.” Tom: “So, how can we tell which companies are actually doing the right thing and cutting their emissions? Google: “There are a number of organisations which certify businesses and state organisations which are taking steps to measure and reduce their carbon emissions. Toitū Envirocare, a subsidiary of government-owned Landcare Research, provides the CarboNZero and CEMARS certifications in New Zealand. The company EKOS also offers certifications in New Zealand. Science-based Target Initiative is a collaboration of environmental organisations which provides certification internationally.” “The B-Corp certification designates companies which take steps to measure and reduce their carbon emissions and otherwise act as good corporate citizens. The Bio-Grow certification for food products insures that they are grown ‘organically’, without pesticides, herbicides and artificial fertiliser, promoting healthy foods and sustainable soil health, which sequesters carbon to soils.” Tom: “Well Marg, I suppose if we are out shopping and want to know if a product is from a company doing the right thing or not, we can always search it on our phones and find out.” Google: “And, please remember to tell them Google sent you!” If you have any questions about climate change and global warming, feel free to visit and ask at Climate Karanga Marlborough’s website (www.climatekaranga.org.nz) or on our Facebook page. We’d be happy to answer them. Now we get the newest fad from the “Not So Fast on Climate Action” crowd; complaining about electric vehicles (EVs), the most conspicuous ones being flashy and expensive Teslas, driven by people from “leafy suburbs” – code for rich people.
The principle gripe seems to be that EV drivers don’t pay road user charges, like drivers of petrol and diesel cars and trucks do. This and the Clean Car discount are, in essence, subsidies that other drivers don’t get. And all that money in subsidies won’t make much difference in the country’s overall greenhouse gas emissions – the money would be better spent elsewhere in reducing emissions. Let’s step back a moment and look at why these subsidies exist. The burning of fossil fuels creates greenhouse gas which is warming our planet and contributing to damaging weather. The world, including New Zealand, needs to stop burning fossil fuels. No one seems to argue with this anymore. So, how do we get to a fossil free world? Unlike for air and sea transport, the technology to eliminate fossil fuels in land transport already exists. All it takes is a transition to electric vehicles. The problem is, technology and production capacity have not matured sufficiently to allow the manufacture of EVs at comparable price to petrol vehicles. For the same size vehicle, EVs are still significantly more expensive. And, not everyone wants to deal with the inconveniences of driving an EV: Limited driving range, limited charging sites, long waits and sometimes queues at charging sites. Driving an EV takes a bit of patience, planning and adaptation that aren’t needed when driving a petrol vehicle. Given the existing price difference, even with the subsidies, no one buys an EV because it is the cheaper and more convenient option. So, it makes sense that the government would “tip the scales”, at least temporarily, to get more people into EVs. If we are going to reach “net zero” greenhouse gas emissions by 2050, expanding the number of electric vehicles in the nation’s passenger fleet is a necessary step. It may not give the best “bang for buck” in eliminating emissions, but it is one of many steps needed to reduce the nation’s emissions. So, for the Tesla-bashers out there, consider these thoughts next time you want an EV to give way to you at an intersection:
In our last episode, Sheriff Cabinet Ministers, in the wild west town of Aeotearoa, turned away from using his trusty ETS sidearm to confront the destructive Climate Breakdown Gang. Things have changed since then. There is a new mayor in town and the Breakdown Gang has wreaked havoc on the Hawkes Bay grocery, the Auckland livery and the Northland Ranch. They’ve slashed up Tairāwhiti. Will he confront them this time? We’ll see in this next, exciting episode.
Camera zoom into the sheriff’s office on Main Street… Sheriff Ministers is having his toast and tea when Deputy Greenie Shaw bursts in. Greenie: “Sheriff, it’s a mess out there. The grocery and the livery are all bashed up and now I’ve got Commissioner Carr asking why we didn’t use the ETS on the Breakdown Gang.” The sheriff leans back and takes a bite of toast, “Just tell Carr that it’s complicated, we gots lotsa irons in the fire”. Greenie: “That’s what I told him before, but he wants more spe-cifics. Should I tell him about the…” Sheriff: “No, don’t mention nothin’ ‘bout the ‘lection. He’ll just think we’re a pack of coyotes who think ‘bout nothin’ more than holding on to our day jobs and sounding ‘portant.” “Besides, that ETS don’t seem to work anyway. I took it out to the Unit Auction for a test fire and it didn’t work. Didn’t get a single bid. I think it was maybe a problem with the reserve price…” Shaw looks incredulous, “Didn’t work? What are we going to use against the Breakdown Gang? Shaw takes his hat off and sits down, pressing his temples. “How about the Biofuels Mandate?” The sheriff sips his tea, “Nah, Mayor Hipkins nixed that.” “The Cash for Clunkers deal to get the high emissions vehicles off the street?” Sheriff: “Gone too.” Greenie: “Expansion of public transport?” Sheriff: “Nope” Greenie: “Maybe the light rail for Auckland?” Sheriff: “History” Greenie: “Surely, we could at least put back the petrol tax. You know, cheaper petrol is playing right into the Breakdown Gang’s hands.” Sheriff: “Not gonna to happen. Hipkins has made some changes round here.” Greenie: “So, what we gonna do? The situation’s getting dire out there! People are hurtin’!” Sheriff: “Well, the mayor has sent around some bread and butter. Maybe that will help. It’s awful good. Here, try some… If he keeps giving these out, maybe he’ll win that ‘lection.” The sheriff hands Deputy Shaw a slice of toast. Shaw looks on in stunned silence. Camera fade to credits. So, dear reader, the situation in Aotearoa is looking grim. As you will recall, cabinet decided in December to ignore the Climate Commission’s advice and kept the Emissions Trading Scheme (ETS) price settings low for this year. As a result, the price of emissions credits fell so low that last quarter’s unit auction actually failed. None of the bids achieved the minimum price set by the Ministry. No emissions credits were sold. Compare this to last year, when a quarterly auction hit the cost containment reserve price triggering the release of extra credits and emissions unit prices were at an all-time high. The price of emissions units has been steadily rising in the last few years, as intended. A failure of the auction is a little bit of good and a lot of bad. Good because it means industry will need to buy the credits they need to surrender for their emissions from the secondary market, soaking up some of the surplus units that Climate Commission has been worried about, but bad because the government didn’t raise any revenue for the Climate Emergency Response Fund like it expected. It’s also bad because the price for a tonne of CO2 emissions has fallen from a high of around $85 late last year to a low of $60 now. Releasing greenhouse gas into our atmosphere has just gotten a whole lot cheaper. And, there’s a whole lot more uncertainty in the ETS market right now. Companies planning to upgrade coal boilers to electricity or wood chip will now look at their balance sheets and wonder if it is still a good idea. It’s maybe going to be cheaper just to pay for more credits, if the price stays low. Yet another delay in the transition to a low emissions future. So, the Climate Breakdown Gang appears to have won this round in Aotearoa, and will have plenty of rein to continue its havoc. I suppose we can all thank the new mayor for our bit of bread and butter, at least until the Climate Breakdown Gang comes back. And, you can rest assured, they will be back. Now we hear from MPI that the Lake Onslow pumped hydro scheme – meant to store enough hydropower for the nation’s electricity shortfall in the event of a “dry year” – is projected to cost 4 times more than initially anticipated – a new price tag of $15.7 billion dollars! In its 16 March newsletter, MPI says it is investigating alternatives.
This setback to the Lake Onslow project isn’t bad news to the many critics of the scheme. It would be a massive engineering undertaking, with a fair risk of becoming an expensive drain on the nation’s resources. There is no estimate yet on how much it would cost, year to year, to keep it topped up to offset losses from evaporation and leakage. The intent of the scheme is noble; to reduce the need to burn fossil fuels for electrical generation during a dry year. But, it’s overall premise seems to violate common sense; why build a massive hydroelectric scheme to address a problem caused by a lack of water? Mother always taught us not to put all our eggs in one basket. Would it not be more logical to focus on other forms of electrical generation that don’t depend upon a scarce, vital resource like water? Maybe a Lake Onslow scheme would get the country through a dry year, but what about two? Or, a dry decade? Global warming isn’t done surprising us. So, what are the alternatives MPI is looking at? Some are seem reasonable, like building a smaller pumped hydro-storage scheme in the central North Island or burning charcoal pellets instead of coal at the Huntly Power Station. It is clear they haven’t thought very hard about the other alternatives. Hydrogen, presumably generated by electrolysis of water and stored underground or as ammonia, still comes up, even though it has dismal efficiency compared to pumped hydro. MPI also mentions something called “flexible geothermal energy” which, to someone who spent a career in the geothermal industry, sounds like an oxymoron (like “open secret”). Due to the thermodynamics of hot water and steam, the operation of geothermal power plants is highly inflexible, otherwise it risks accelerated damage to its most valuable asset – the geothermal wells. What they don’t consider is accelerated development of renewable power sources, such as wind, solar and tidal power. An abundance of these affordable, renewable power sources, along with charcoal at Huntly and a few pumped hydro-storage projects around the country, would fit well with an “eggs in different baskets” strategy. MPI fears that overbuilding wind and solar would lead to higher market prices for electricity. How too much electricity leads to higher prices isn’t clear. Perhaps the problem is actually the power market itself. I ask you, which would give better bang for buck: $16 billion for a pumped hydro project at Lake Onslow or reforming the New Zealand electricity market to promote an abundance of wind, solar and tidal generation? The present generation spot market is dominated by a quasi-monopoly of four big, highly profitable companies. The market incentivises shortages by setting higher prices when electricity supplies are short, which has resulted in retail electricity prices rising faster than inflation. The 1998 Bradford reforms, which were supposed to deliver cheaper electricity to consumers, has resulted in ever increasing energy bills for residential customers and ever fluctuating power prices for industrial customers. It has clearly failed to deliver on its promise of cheaper power. Reform is well overdue. How about, instead of looking to build giant infrastructure projects like the Lake Onslow scheme, the government focus on reforming the electricity system so that it provides the generation needed to get us through a dry year (or decade). That reform might also look to provide reasonable and stable power prices to consumers and industry, instead of the escalating prices we are seeing now. The Interim Climate Change Commission has pointed out that lower retail electricity prices will also act to reduce greenhouse gas emissions, by further incentivising industry to replace fossil fuel in process heat and transport with electricity. Reportedly, that uncertainty in the future price in electricity is holding many companies back from making the transition. So, low and stable electricity prices will help abate carbon emissions too. And for Kiwis struggling to make ends meet, a lower, more certain electricity bill would be a welcome sight. Tom Powell and Tim Jones – Coal Action Network Aotearoa
This is how technology advisor Michael Liebreich recently described hydrogen in Threadreader. In some renewable energy circles, green hydrogen is all the rage. It can be made from ordinary water and electricity. It can be burned like fossil gas but without the greenhouse gas emissions. And, it can be used in fuel cells to make electricity again. What is there not to like? Quite a lot, it turns out. The usual argument against using green hydrogen for energy is the abysmally poor efficiency of turning electricity into hydrogen and then turning it back into useful energy. Presently, a hydrogen fuel cell vehicle gets back only about 30% of the electrical energy used to make the green hydrogen in powering the vehicle. A typical battery electric vehicle gets back around 80% of the electrical energy used to charge its batteries. The Parliamentary Commissioner for the Environment, in a December letter to Megan Woods, criticised proposals to use wind power to make green hydrogen at Taranaki, store it underground until needed then burn it to make electricity again, due to the lifecycle efficiency of only 20%. By comparison, pumped hydro storage has a lifecycle efficiency of about 75%. There are better ways to store energy than converting electricity to green hydrogen. Like the petroleum fuels we have grown to know and love, hydrogen’s best attribute is that it is a flammable fuel that can be moved around and stored. But, what about the other properties of this weird and wonderful new fuel? Let’s first talk about “escapey”. Hydrogen is a very small molecule and being small, it can squeeze through most materials. It leaks through ordinary carbon steel, which is what most fossil gas pipelines are made of. Along the way, it can cause “hydrogen embrittlement” which further weakens the steel. So, here we have a flammable gas that needs careful containment in special materials. Now, let’s talk about “explodey”. Hydrogen is flammable in air with a wide range of concentration, 4% to 74% by volume. By comparison, fossil gas is flammable in air with a concentration range of 4.4% to 17%. Hydrogen burns with a flame invisible in daylight – when it is burning, you can’t see it. It also has a very low ignition energy – a spark of static electricity is reportedly enough to set it off. And, it is known to ignite for unknown reasons when suddenly decompressed, as with the rupture of a high pressure fuel tank. Add to this the fact that when it leaks, you won’t be able to smell it, like you can fossil gas. Hydrogen has to be very pure in order to work in automobile fuel cells, so perfume can’t be added. Sophisticated sensors are needed to detect leaking hydrogen. There have been a number of recent accidents due to hydrogen explosions: one in South Korea in 2019 and one in Norway, also in 2019. And, what’s this about “expanded polystyrene”? Hydrogen is much lighter than air, which is why it was used to lift early dirigible air ships, at least until the 1937 Hindenburg disaster. Being so light, it is still pretty light when compressed or liquefied. Hydrogen compressed to the NZ standard storage pressure of 350 bar (5,000 psi –14 times the pressure in an LPG tank and 2 times the pressure in a SCUBA tank) has a density of only 23 kg per cubic metre – about the same as expanded polystyrene used for home insulation. So, although it holds about 3 times more energy per kilogram than gasoline, the same amount of energy requires roughly 12 times the volume. Fuel tanks for trucks or aeroplanes would need to be many times larger, and many times stronger, than petrol tanks, in order to drive or fly the same distance. The upshot of all this is that hydrogen is not an easy or efficient fuel to work with. We will need special materials to store and transport it – materials that keep it from leaking out, as well as hold it at very high pressure. We’ll also need lots of sensors to make sure it doesn’t leak and explode. Green hydrogen is not all bad, however. It has a role in reducing emissions in the manufacture of steel and fertiliser, for instance, but that is very different than using it as a transport fuel. When you add to this the poor round trip efficiency of turning electricity to green hydrogen and back to useful energy again, requiring abundant renewable electricity that Aotearoa New Zealand doesn’t have at the moment, we can only hope that somebody comes up with a better renewable fuel than hydrogen. Otherwise, I am afraid we are in for an “escapey, explodey, expanded polystyrene” future. |
Authors
These are a collection of opinion articles principally written by CKM member Tom Powell for the Marlborough Express. Tom is a retired geologist who came to New Zealand in 2004 to work in the geothermal industry on the North Island, is a New Zealand citizen and now lives in Blenheim. Some articles have been written by other CKM members, and their names appear with those articles. Archives
December 2023
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