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Single-bladed floating wind turbine promises half the cost, more power

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We haven't seen a floating offshore wind turbine like this before. Touchwind claims its innovative single-blade turbines will solve several problems to drive down cost and downtime, using a single, huge blade with no fancy active pitch controls.

Most of the world's best wind resources are way offshore, in ocean far too deep to exploit with typical fixed-tower turbines. The deep sea could thus make a huge clean power contribution, while creating far less trouble for residents and wildlife than onshore wind farms.

But the technology to harness offshore wind from floating devices anchored to the sea bed is far from settled, so there's a gold rush of sorts in progress as some radically different designs duke it out on the spec sheet, in wave tanks and in prototype testing. They're all hoping to find the sweet spot between cost, power generation, cost, longevity, reliability, cost, ease of manufacture, ease of installation and maintenance, cost, cost and cost.

Dutch company Touchwind has an interesting spin on the idea... waka waka. It's designed around a massive single-piece rotor, sitting on the end of a pole that's draped over a big barrel, with a large floating buoy hanging beneath it.

This one huge double blade, says Touchwind, should cost around 30% as much to make as the triple-bladed arrangements on traditional turbines. It doesn't require any expensive active blade-pitch control systems, and where most standard turbines need to shut down in wind speeds above 25 or so m/sec (90 km/h / 56 mph), this one is rated for speeds as high as 70 m/sec (252 km/h / 157 mph). Less downtime equals more productive hours and more energy.

The blade is fixed to the mast at a slight upward angle. At low wind speeds, the mast tilts right over, and effectively the blade stays out of the water with the assistance of that dangling buoy. But as wind speeds pick up and the blade starts spinning fast, it develops lift, much like a helicopter's main rotor, and begins pulling the mast upright.

Thus, in high wind speeds, it sits nearly flat to the horizon, greatly limiting the wind's ability to spin it faster. And as this happens, the buoy is lifted out of the water, becoming a ballast weight acting against the lift of the main blade, helping to reduce stress on the sea floor anchors and prevent the whole thing from taking off and starting a new life where nobody knows its name.

As with many other floating designs, it's agnostic to the direction of the incoming wind, and will passively float around to orient itself in the optimal direction at all times.

Touchwind says the design lends itself to easy manufacture at more or less any harbor facility capable of handling the 200-m (656-ft) blade required for a 12-MW turbine, and it's similarly easy to tow out to site and attach to a ground anchor and power export cable for installation.

The company has completed both land-based and floating platform prototypes at small scale, and is beginning to expand testing thanks to fresh investment from Japanese shipping company Mitsui O.S.K. Lines.

"We have been working together for a year now on the further development of our floating wind turbine," said Touchwind Founder and CEO Rikus van de Klippe, in a press release. "Field testing with a 6-m diameter rotor is in full preparation at the Oostvoorne lake in the Netherlands. With MOL as a shareholder and their investments we can speed up our testing program, prove our technology and reduce time to market."

We're not sure when the company expects to be operating at scale, and unfortunately, there are no projections at this stage on what the levelized cost of energy (LCoE) from these beasties might look like. So it's hard to get a read on how competitive it might be in a commercial deployment, assuming development and funding proceed without too much drama.

Check out a video below.

TW Mono v1.0

Source: Touchwind via Recharge News

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3 days ago
Cambridge, London, Warsaw, Gdynia
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What Are Dreams For?

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In the late nineteen-nineties, a neuroscientist named Mark Blumberg stood in a lab at the University of Iowa watching a litter of sleeping rats. Blumberg was then on the cusp of forty; the rats were newborns, and jerked and spasmed as they slept. Blumberg knew that the animals were fine. He had often seen his dogs twitch their paws while asleep. People, he knew, also twitch during sleep: our muscles contract to make small, sharp movements, and our closed eyes dart from side to side in a phenomenon known as rapid eye movement, or REM. It’s typically during REM sleep that we have our most vivid dreams.

Neuroscientists have long had an explanation for our somnolent twitches. During REM sleep, they say, our bodies are paralyzed to prevent us from acting out our dreams; the twitches are the movements that slip through the cracks. They’re dream debris—outward hints of an inner drama. Human adults spend only about two hours of each night in REM sleep. But fetuses, by the third trimester, are in REM for around twenty hours a day—researchers using ultrasound can see their eyes flitting to and fro—and their whole bodies seem to twitch. When a mother feels her baby kick, it may be because the baby is in REM sleep. Once born, babies continue to spend an unusual amount of time in REM, often sleeping for sixteen hours a day and dreaming for eight.

Increasingly, these facts struck Blumberg as odd. In adults, dreams are offshoots of waking life: we have experiences, then we dream about them. But a baby in the womb hasn’t had any experiences. Why spend so much time in REM before you have anything to dream about? According to the dominant theory, the rats’ twitching eyes were supposedly looking around at dream scenery. But the rat pups were just days old; their eyelids were still sealed shut, and they’d never seen anything. So why were their eyes—and their whiskers, limbs, and tails—twitching hundreds of thousands of times each day?

Blumberg decided to put the dream-debris theory to the test. He surgically removed the rats’ cortex—the brain region, involved in visual imagery and conscious experience, where dreams were believed to originate—leaving only the brain stem, which controls subconscious bodily functions, intact. The sleeping pups continued to twitch exactly as before. “There was no way that twitching was a by-product of dreams,” Blumberg told me, when we spoke last fall.

Now in his sixties, Blumberg is the chair of the Department of Psychological and Brain Sciences at the University of Iowa. He has spent the past twenty years studying sensorimotor development—the process through which an infant’s brain links up with its body. Twitches had long been overlooked by sensorimotor researchers. “If you’ve been told since Aristotle that they’re remnants of dreams—well, who wants to study a remnant?” he said. But, in fact, the science of dreams was far from settled. Freudians believed that they contained repressed wishes dredged from the dark corners of psychic life; many neuroscientists have seen them as random brain chatter. Some theories have suggested that dreams consolidate our memories, others that they help us to forget. With twitches, Blumberg had identified a new thread in the mystery of dreaming. By pulling, could he unravel the whole?

For centuries, how we think about dreams has shaped how we think about minds. On the night of November 10, 1619, René Descartes dreamed that he was stumbling down the street pursued by ghosts. His right side was weak, and a whirlwind spun him violently on his left foot; he limped past a man whom he suddenly realized he knew, then turned to speak to a different man, who told him to go see Monsieur N., who had something to give him. Descartes knew what it was: a melon.

A lesser thinker might have seen in this dream a craving for cantaloupe. But, to Descartes, its vividness seemed to suggest a clear disjunction between the body and the mind: in dreams the body lies dormant while the mind runs free. Today, scientists often draw a similar distinction, albeit between the body and the brain, rather than the immaterial mind.

This notion was bolstered by early sleep science. In 1953, when two scientists at the University of Chicago, Eugene Aserinsky and Nathaniel Kleitman, discovered REM sleep, they found that it was accompanied by surprisingly high levels of activity in the brain—as if the dreaming brain had woken up while the body remained sleeping. In the following years, the American sleep scientist William Dement and the French neuroscientist Michel Jouvet each observed that, when cats enter REM, they lose all muscle tone. The same is true for humans—the result, Jouvet discovered, of inhibitory signals, sent by the brain to the spinal cord, that paralyze the body. When this paralysis fails, it results in REM behavior disorder, in which people may talk, kick, and even act out violently in their sleep. When it persists, we experience “sleep paralysis,” in which we wake up unable to move. When the system works as it should, Jouvet wrote, we enjoy “paradoxical sleep”: our brains come alive with wild visions as our bodies go motionless between the sheets.

Researchers attempted to determine whether the paralyzed body could influence the dreaming brain. They pumped the odor of peppermint into sleepers’ noses, hoping to create scented dreams, to no effect. They taped dreamers’ eyes open and showed them various objects—a coffeepot, a handkerchief, an ironic “Do Not Disturb” sign—hardly anyone reported dreaming about them. The brain is less responsive to sensory input during REM sleep, which is why even a blaring alarm clock can fail to wake us.

By the late nineteen-seventies, the idea of a total “input-output blockade” between body and brain during REM sleep had emerged. J. Allan Hobson, the late Harvard Medical School psychiatrist, proposed that dreams were constructed when random signals from the brain stem were interpreted by the cortex as signals from an outside world. “Dreaming is no longer mysterious,” he declared. And yet the theory couldn’t explain why we dream what we dream, or why we feel what we feel when we dream it. In the following decades, scientists challenged, revised, and even rejected Hobson’s theory, but they largely retained its core assumption about the severed connection between brain and body.

“I’ve been collecting videos of all kinds of cool animals sleeping,” Blumberg told me. His collection includes monkeys, pigeon chicks, jumping spiders, and fetal sheep. There are the quivering antennas of honeybees, and the fidgeting fists of kangaroos. In one video, a sleeping octopus kaleidoscopes from one camouflage to another as the muscles controlling its chromatophores move beneath its skin. The videos attest to the apparent universality of twitching: not only do many animals twitch in REM but they start before they’re born.

After finding that sleep twitches in early development aren’t caused by activity in the cortex, Blumberg increasingly wondered whether it might be the other way around—perhaps the twitches were sending signals to the brain. Hardly anyone had considered this possibility, because it was assumed that the blockade would keep sensations out. It took Blumberg and his team years to build equipment capable of getting clean brain recordings from tiny, wriggling pups, but eventually, they were able to implant electrodes into rat pups’ brains, recording their neural activity while high-speed cameras captured their twitching.

The results were startling. “I could explain it in words, but it might help to see what it looks like,” Blumberg said, pulling up a video on his screen. It showed the front paw of a sleeping rat pup, hanging limp. “We assigned a different sound to each neuron in the brain that we’re recording from,” he explained. When he started the video, the paw began to twitch—and, with each twitch, musical notes resounded from different neurons in the brain. The effect was like a church organ playing underwater; chords rolled then subsided. An electrode readout made the order of events clear: first the pup moved, then the brain responded. Bursts of activity in the sensorimotor cortex, which coördinates movement and sensation, followed the twitches. The body and brain weren’t disconnected. The brain was listening to the body.

In a series of papers, Blumberg articulated his theory that the brain uses REM sleep to “learn” the body. You wouldn’t think that the body is something a brain needs to learn, but we aren’t born with maps of our bodies; we can’t be, because our bodies change by the day, and because the body a fetus ends up becoming might differ from the one encoded in its genome. “Infants must learn about the body they have,” Blumberg told me. “Not the body they were supposed to have.”

As a human fetus, the thinking goes, you have nine months in a dark womb to figure out your body. If you can identify which motor neurons control which muscles, which body parts connect, and what it feels like to move them in different combinations, you’ll later be able to use your body as a yardstick against which to measure the sensations you encounter outside. It’s easier to sense food in your mouth if you know the feeling of a freely moving tongue; it’s easier to detect a wall in front of you if you know what your extended arm feels like unimpeded. In waking life, we don’t tend to move only a single muscle; even the simple act of swallowing employs some thirty pairs of nerves and muscles working together. Our sleep twitches, by contrast, are exacting and precise; they engage muscles one at a time. Twitches “don’t look anything like waking movements,” Blumberg told me. “They allow you to form discrete connections that otherwise would be impossible.”

While he spoke, I stared, mesmerized, at the rat pup’s twitching paw. Blumberg suspects that it was twitching “to build its sense of self.” The theory, he pointed out, turned the rationale for REM paralysis on its head: the paralysis isn’t there to stop the twitches but to highlight them. It’s a process that’s most important in infancy, but Blumberg thinks this might continue throughout our lives, as we grow and shrink, suffer injuries and strokes, make new motor memories and learn new skills. Blumberg plays the drums, and, when he learns a new rhythm, he wonders whether sleep is involved. “You struggle and struggle for several days, then one day you wake up and start playing and boom—it’s automatic,” he said. “Did sleep play a role in that? If I had been recording my limb movements, would I have seen something interesting? That keeps me up at night.”

Throughout the years, I’ve sometimes recorded my dreams in notebooks. After talking to Blumberg, I pulled out an old one and flipped through it. Some were full-fledged narratives. (My car, of its own volition, drives me to the woods to see a rare species of duck; when I arrive, the duck has been murdered, and I’m accused of the crime.) Others were just images. (A billboard shows a man squatting over a bidet with a confused and frightened look on his face; he’s shouting, “Get my wife!”) Sometimes I’d written down only enigmatic sentences: “Shark bird flew into my mouth.” How did tiny muscle movements, supposedly designed to wire up my sensorimotor system, result in such demented stuff? By what twisted route does one go from a twitch to a shark bird?

For clues, I consulted “Dreaming,” by Jennifer Windt, a philosopher of mind at Monash University, in Australia. In the course of eight hundred pages, Windt seeks to answer big questions: What kinds of experiences are dreams? Why do they feel so strange yet so meaningful? What can they tell us about consciousness? She synthesizes the philosophy and science of dreams, encountering the input-output blockade everywhere she looks. In dreams, Hobson writes, our brains create “an impressively rich state of consciousness” without any information from the senses. According to the neuroscientist Christof Koch, in his book “Consciousness,” paralysis in dreams proves that “behavior is not really necessary for consciousness”—“the adult brain, even if cut off from most input and output, is all that is needed to generate that magical stuff, experience.”

When Windt began her research, she told me, she, too, was convinced that “dreaming shows that everything we’re experiencing is a product of the brain.” As she dug deeper, however, she found a number of studies suggesting that our bodies can in fact shape our dreams. Eventually, she stumbled upon Blumberg’s experiments. (“I was really excited when I found his work,” she said.) Research suggests that dreaming brains still register the erratic heart rate, variable breathing, and fluctuating blood pressure that are typical during REM sleep. Some scientists believe that a dreaming brain may be keyed into the body’s vestibular system, which uses organs in the inner ears to detect accelerations and rotations, telling us how we’re positioned and whether we’re moving. Without visual cues, the system can’t tell the difference between gravity and acceleration, making it difficult to detect whether you’re lying still horizontally or standing vertically and moving. When I consulted my dream notebook, I saw that I was upright and moving in nearly every dream I’d recorded; even when I was seated, I was still being moved—by a train, an airplane, or, in one case, a demonically possessed swivel chair.

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20 days ago
Cambridge, London, Warsaw, Gdynia
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Should you put tea bags in your food waste bin?

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There has been long-standing confusion over how to dispose of tea bags and whether or not they should go in the food waste bin. As the industry continues to transition from plastics to bioplastics, the answer is not so simple. 

Should you put tea bags in your food waste bin?Tea: Britain's favourite drink. Second only to water. As a nation we consume 100 million bags of tea each day - that's a lot of cuppas and a lot of used bags to deal with. But does anyone really think about what happens to their tea bag once it's been dunked and dumped?

Most people wouldn’t consider their tea bags plastic – after all, they look like plain old paper and leaves – but many are actually sealed shut with plastic fibres that can make up nearly 25 per cent of each bag’s weight.

All ‘round’, ‘pyramid’ and ‘pillow’ tea bags have to be heat-pressed into their unique shapes. During this process, plastic fibres embedded in the outer layers of each bag melt and fuse together, forming a seal. In the past, the material used for this purpose was a non-biodegradable plastic called Polypropylene (PP).

Because of the nature of the seal, PP fibres cannot be easily separated from the organic materials in the rest of the bag, making them difficult to dispose of separately.

Recent awareness around the potential effects of microplastic pollution on the environment, and on ourselves, has led to some major brands turning to a new, biodegradable alternative: Polylactic Acid (PLA) – a bioplastic derived from corn.

Major brands like Tetley, PG Tips, Yorkshire Tea and Twinings all now use PLA-sealed bags in their best-selling ranges of teas. With its recent switch to PLA, PG tips alone claims to have saved 330 tonnes of ‘traditional plastic’ from entering the waste stream each year, plastic that might otherwise have ended up in British soils.

The question is, with both PLA and PP fibres still on the market, how should the consumer be disposing of their bags of tea? And what, if any, are the effects of these plastics, plant-based or otherwise, on our food waste streams?

Can PLA tea bags go in the food waste?

PLA-sealed bags are sometimes labelled ‘plant-based’, ‘biodegradable’ or even ‘plastic-free’, but this can be misleading. PLA might be derived from plant matter but it’s still fundamentally a plastic. Sugars from corn, sugar cane and other agricultural products are fermented to form the lactic acid monomers that are the building blocks of the polymer itself. It’s not made from petrochemicals, but PLA will still stick around for a long time under natural conditions. There’s even some evidence to suggest that littered bioplastics could have a stronger effect than conventional ones on the quality of soil.

The great advantage PLA does have is that it can be broken down in industrial conditions and metabolised by microorganisms, leaving no contaminants behind in the soil.

PLA bags are designed to be disposed of through organic waste collections. They can’t be composted domestically, and it may take 100 years for one per cent of the PLA sent to landfill to degrade. Only in the warm, wet, microbe-rich environment of an industrial composter can PLA break down properly. Here, in the heat and humidity of the reactor, the polymer splits into smaller components before being eaten up by microorganisms.

In many ways the switch to PLA is a uniquely elegant solution for tea bags: most people already throw their tea bags in the food waste and most bags already end up in anaerobic digesters and industrial composting facilities. Neither consumer behaviour, nor waste-stream infrastructure needs to change to take advantage of the technology, and the small amounts of PLA present in the bags break down quickly under the normal operating conditions of an industrial composter.

Whilst treatment of PLA tea bags as part of the food waste stream is the preferred route, not everyone in the UK has access to food waste collection, which is available in just under a third of England’s local councils and unitary authorities, although the government plans to cover every house by 2025. Until then, the refuse bin may be the simplest solution for those without coverage.

Handling polypropylene tea bags

The switch to PLA has sped up since Clipper put its first ‘plant-based’ bags on the market in 2018, but there are still plenty of traditional PP-sealed products on the market today. The transition between materials is not seamless, and manufacturers are having to build modified presses to work with the new bioplastics in their seals. Even large brands like Twinings and Tetley that have adopted PLA in their flagship products still use PP-sealed bags in parts of their ranges – their less popular ‘specialty’ teas – and don’t yet have the presses they need to seal these bags with PLA.

While the transition continues, PP from some other brands and from these smaller ranges will continue to enter the organic waste stream, albeit in smaller and smaller amounts. Once collected as part of food or garden waste (as recommended by RecycleNow), the tea and paper in these bags are broken down in industrial facilities to produce a ‘digestate’ leaving the PP seal behind to break into smaller fibres or remain in the form of a plastic ‘skeleton’. This product is then sieved and checked for contaminants as part of a routine quality control called a PAS test.

The problem is that these fibres cannot all be filtered out during the PAS process. They are small and flexible, and even undegraded seals may simply fold through the 2mm screen. Once they’re through they can be hard to spot.

In 2018, while PP seals still dominated the market, Resource spoke to Charlie Trousdell, a waste resource energy consultant and then chair of the Organics Recycling Group, about the disposal of PP tea bags, and he stated: “Since they are fibres – we are talking a few microns thick here – they will not lead to a PAS failure or even be that visible during inspection so it is hard to know their fate in the soil.”

Any PP fibres left behind by the PAS screening process would be mixed into the digestate and become contaminants. While the concentrations of PP entering the soil this way might be small they could still bring about negative repercussions. There is even research to suggest that PP microfibers, once present in soil, can have adverse effects on physical properties such as bulk density, aggregate stability and water retention capacities.

Perhaps because of this, the UK Tea & Herbals Association, cited by Tetley, recommends either throwing PP-sealed bags into landfill (contributing to methane emissions) or, if you have a garden compost, tearing open the bags, composting the leaves and throwing the rest away in the general waste – an unlikely solution on account of the UK’s low home-composting rates. According to a BusinessWaste survey of 2015 UK households, only three per cent had compost heaps or bins in their gardens.

WRAP gives different recommendations, saying all teabags should be placed in food or garden waste collections ‘to help prevent greenhouse gas emissions from teabags rotting down in landfill’.

Ultimately, consumers would be hard-pressed to know for sure what their tea bags are made from at the point of purchase and, while brands continue their transition towards PLA-based seals, it may be better to have what is now becoming a smaller and smaller amount of plastic going into compost than to have all those tea bags producing methane in UK landfills.

Going totally plastic-free

Compostable bioplastic seals are certainly a step in the right direction, but some providers, like Pukka, Hampstead Tea and Neil’s Yard Tea, have cut out plastic entirely – they all make their bags with wood pulp and plant cellulose, sealing them bags with either staples or cotton stitches that make them fully compostable. If you want to avoid microplastics in your compost or tea, these brands might be for you.

But there has always been one surefire way to keep plastics out of your tea: no bag at all – the traditional teapot and strainer method, which comes in all manner of different infusers and inbuilt strainers, making it a more convenient option when throwing away pesky leaves. Loose leaf alternatives are available already in most supermarkets and are often better quality. Not to mention, if you went bagless, you would have the blessing of George Orwell – that other great authority on tea-making – who instructed in his 1946 essay A Nice Cup of Tea: “The tea should be put straight into the pot. No strainers, muslin bags or other devices to imprison the tea."

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24 days ago
Cambridge, London, Warsaw, Gdynia
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Ecological Cliff Edge | Do the Math

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The numbers had already left impressionable marks on me, and as they swirled in my head for some months I certainly had a sense for the urgent warning they wanted me to hear. But it wasn’t until I rubbed the numbers together that the message really rang out. Then plotting the historical evolution shook me anew.  I was staring at the ecological cliff we appear to be driving over.

Let’s build the punchline from a few facts that were already rattling around in my head. Human population, at 8 billion today, was 1 billion around the year 1800. At a global average human mass of 50 kg, that’s 400 Mt (megatons) of humans—matching the 390 Mt I had seen in a superb graphic from Greenspoon et al., shown later in this post. This same graphic shows wild land mammal mass at 20 Mt today. I also knew that wild land mammal mass was about 4 times higher in 1800, and 5 times higher 10,000 years ago.

Put these together, and what do you get? In 1800, every human on the planet had a corresponding 80 kg of mammal mass in the wild. Wild land mammals outweighed humans in an 80:50 ratio.

Today, each human on the planet can only point to 2.5 kg of wild mammal mass as their “own.”

Let that sink in. You only have 2.5 kg (less than 6 pounds) of wild mammal out there somewhere. A single pet cat or dog generally weighs more. Not that long ago, it was more than you could carry. Now, it seems like hardly anything!  I especially fear the implications for mammals should global food distribution be severely crippled.

The graph is even more alarming to me.

Mass ratio (left axis) and total mass (right axis) of wild land mammal mass per person on the planet.  Note the logarithmic vertical axis, as is necessary to show the wide range of values.

The vertical scale is logarithmic in order to show the enormous range involved. The precipitous drop in the present age is staggering. How can we look at this and think that we’re heading in the right direction? That’s modernity for you, folks.

I front-loaded the core content, and what follows is simply housekeeping. First, here is a linear graph of the tail end of the long-term graph.

Linear plot of the same data in recent centuries: nearing zero!

We’re almost there! We can do it! Or wait: pull up! Pull up!

Most of the character in the curve—especially until about 1800— is simply a reflection of growing human population while land mammal mass was relatively stable. Since that time, human population has increased eight-fold, while mammal mass has decreased by a bit more than a factor of four. Combined, this is about a factor of 35 (e.g., roughly 80 kg vs 2.5 kg per person).

For mammal mass, I used two sources. One came from an aggregation of data incorporating Barnosky (2008), Smil (2011) and Bar-On et al. (2018), as presented here. These data show dry carbon mass of land mammals declining from 15 Mt 10,000 years ago to 10 Mt by 1900, and 3 Mt today. From this, I construct a smooth exponential fit that looks like 15.0 − 10.37×exp[(year – 2000)/137.07].  The graph, below, also appeared in the Death by Hockey Sticks post.

Biomass of wild mammals on land; data from OWID.

I translate the dry carbon mass into living wet mass based on the Greenspoon et al. (2023) data.

Current mammal mass distribution, as presented in Greenspoon et al. (2023)

The graphic shows wild land mammals at 20 Mt, implying that 15% of the mass is in the form of dry carbon. This checks out against other information: 70% of mass is water, and half of the dry mass is in carbon form.

Incidentally, straight from this graphic, we see that land mammal mass is only 5% of human mass. At an average human mass of 50 kg, we recover the 2.5 kg of mammal mass per person.

That’s all. It’s a brief “special edition” post without elaboration. The shocking result speaks for itself. What the hell are we doing?

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33 days ago
Cambridge, London, Warsaw, Gdynia
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Ebb Carbon wants to pull CO2 from the sky with electricity and seawater

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Since launching in 2021, Ebb has raised over $25 million in seed and venture capital funding to develop and deploy its electrochemical system, which can fit inside a 20-foot shipping container.

The technology builds on years of research led by Matt Eisaman, the company’s CTO and co-founder, who recently joined Yale University’s Center for Natural Carbon Capture as a faculty member. Eisaman first met Tarbell, a former SolarCity executive, several years ago when both were working with Alphabet’s innovation arm, X.

Ebb plans to partner with existing sites that already process seawater, such as desalination plants or aquaculture facilities. The company will intercept some of the saltwater and, using electricity, run it through a stack of ion-selective membranes. The device then rearranges the salt and water molecules to produce two streams — one acidic (hydrogen chloride) and the other alkaline (a dilute form of sodium hydroxide). The acid is kept on land, while the alkaline seawater flows back out through the site’s wastewater system.

When alkalinity is added to seawater, it reacts with the CO2 in the atmosphere to become bicarbonate, a form of carbon that can stay trapped in the sea for thousands of years — without increasing the ocean’s acidity. On a local level, some amount of alkaline seawater might even act as an antacid to protect marine life from increasingly hostile waters.

The ocean has absorbed roughly 30 percent of the carbon dioxide released by humans since the Industrial Revolution, which is causing ocean acidification that harms coral and shell-forming animals and disrupts fish behavior. Human-caused climate change is also partly the reason why Earth’s oceans are now the hottest they’ve ever been in modern history, scientists say.

Ocean-based solutions need more science

Still, given how fragile marine ecosystems are already, some environmental groups are pushing back against pursuing technological fixes that could disrupt the ocean’s delicate balance even further, calling instead for more urgent action to reduce greenhouse gas emissions. While each type of ocean-based CO2 removal carries its own potential risks, they all share a common challenge: a lack of well-established research.

Carbon180, a nonprofit that advocates for carbon-removal solutions, says it doesn’t endorse or oppose” any ocean-centric methods because so little is known right now about how effectively they’ll work at removing CO2, or how they might impact marine environments and the coastal communities that depend on them.

We don’t really have the data sets to say what is going to happen if we do gigatons of ocean-based carbon dioxide removal,” said Anu Khan, Carbon180’s deputy director of science and innovation. She said that designating a federal agency to oversee these types of projects could make it easier to coordinate research, funding and, eventually, permitting and regulations.

The efforts now underway in Sequim Bay are an important early step toward addressing the sector’s many unknowns, Meinig said.

At PNNL’s waterfront lab, intake pumps draw thousands of gallons of Pacific Ocean water into large circular tanks. While Ebb’s earliest experiments used table salt and water, the ongoing study is using biologically alive” seawater replete with microorganisms.

Scientists are using sensors and software controls to measure how acidic or alkaline the water is once it runs through the electrochemical system, and to understand how much CO2 is turning into bicarbonate. In a smaller aquarium, they’re also testing to see how organisms like sea slugs, isopods and oysters fare when exposed to varying pH levels, said Nicholas Ward, an earth scientist based at PNNL’s Sequim lab.

The data is used to inform sophisticated computer models, which help predict what’s likely to happen when the system is deployed at larger scales and in real-world conditions. Later steps will involve testing the technology in the bay, using buoys to measure how much alkalinity the system is adding to the seawater and assessing how the ecosystem responds.

Ebb Carbon and PNNL didn’t share the total cost of the research project. But the two-year initiative has received funding from the National Oceanic and Atmospheric Administration’s Ocean Acidification Program, the Department of Energy’s Water Power Technology Office, the National Oceanographic Partnership Program and the nonprofit ClimateWorks Foundation.

The PNNL researchers said they hoped their lab could establish a center of excellence” of sorts in the future to serve the growing tide of carbon-removal companies looking to test and validate their ocean-based technologies.

We need to be doing this [carbon removal] at speed and scale,” Meinig said. However, in order to go fast, we might have to start slow…and invest in the research to do so responsibly and effectively.”

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33 days ago
Cambridge, London, Warsaw, Gdynia
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Fusion Foolery | Do the Math

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National Ignition Facility at the Lawrence Livermore National Lab

Great. The fusion hype is bad enough already. Now its resurgence is going to interrupt the series of posts I’m in the middle of publishing in order for this post to be “timely.”

The first (and much bigger) round of breathless excitement came in December 2022 when the National Ignition Facility (NIF) at the Lawrence Livermore National Lab (LLNL) announced a (legitimate) breakthrough in achieving fusion: more energy came out of the target than laser energy injected.

At the time, I brushed it off without even reading any articles because I already knew about the NIF’s purpose and limitations, and a few headlines told me everything I needed to know. Who cares how much laser energy went in: how much energy went into creating the laser energy? The laser I used for lunar ranging took 5 kW from the wall plug and delivered 2 W of laser power for a dismal 0.04% efficiency. Such is the cost for shaping ultra-brief pulses: lots of energy is thrown away. The headlines were clearly overblown.

Enough students in my energy class in Spring 2023 asked about the fusion breakthrough (doesn’t that mean we done?) that I dug into the details. Even so, I still deemed it unworthy of writing up as a post. But a few days ago, my friend asked me if I was excited about the recent fusion news. I hadn’t heard a peep, but after searching I found a new round of articles based on a second “net gain” laser shot and realized I probably ought to put out a quantitative post on the matter, reminiscent of my blogging origins.

In the end, the NIF fusion accomplishment might be called a stunt.  Stunts explore what we can do (often after an insane amount of preparation, practice, and failure), rather than what’s practical.  Stunts hide the pains and present an appearance of ease and grace, but it’s a show.

Quantitatively, it’s as if you spot a slot machine in a casino that looks very promising. You’re dying to play, because it just feels right—mysteriously appealing to your sense of self. It calls to you. You notice that it takes $2 tokens, but you have none. You go to the window to purchase a token, and are shocked to learn that one $2 token costs $400. Not wanting to look like an uninformed fool, you gulp and buy the token. This slot machine had better live up to its promise! You pull the lever, and surprise! You actually do win! You put in a $2 token and the machine makes very happy noises and flashes lots of lights as it spits out…$3 (and some neutrons, oddly). Queue the headlines! Want to play again?  Actually, this wasn’t your first shot: just the first success after years of trying (but hush!).


That’s the essence of the story. The December announcement indicated that they launched 2.05 MJ of laser energy onto the target sphere, and 3.15 MJ came out. The recent articles indicate a second “score,” but fail to give energy specifics, other than “more” energy out. I am assuming an incremental bump, still under 4 MJ—otherwise the factor of improvement would be prominently touted in the coverage.

Let’s pause to say: well done! Honestly. No sarcasm. What they did was ridiculously hard, and it actually worked after more than a decade of trying. They actually produced a significant number of fusion events! There’s no faking that, and I’d like to see you try. So let’s be clear that I’m not knocking the accomplishment in itself. My major beef is how we interpret the implications for society. To be fair, the scientists did not supply the hype. They didn’t have to: the rest of the universe was more than ready to fill in that yawning gap.

As I scanned articles from December 2022, most were about the triumph, a reminder that the sun works by fusion, and talk about being the first major step toward limitless clean energy. That’s what people want to hear. It plays right into our cultural mythology: humans defy all limits through ingenuity and technology. Build a story around that theme, and you’ve got yourself some guaranteed click-bait.

A very few articles mentioned the energetic price of generating the laser pulse. In particular, I found one in The Atlantic by Charles Seife:

The “more energy out than laser energy in” equation masks several fundamental problems. NIF’s doped glass lasers have an efficiency of about 0.5 percent, meaning that they would have sucked in roughly 400 megajoules of energy from the grid in order to produce the 2.1 megajoules of light energy…

The second was a Big Think article by Tom Hartsfield.

The laser energy delivered to the target was 2.05 MJ, and the fusion output was likely about 3.15 MJ. According to multiple sources on NIF’s website, the input energy to the laser system is somewhere between 384 and 400 MJ.

And that’s just the laser energetics. The whole facility consumes scads more for countless other purposes. According to the LLNL NIF FAQs (are you letting me get away with a triple acronym?),

NIF’s 192 powerful laser beams, housed in a 10-story building the size of 3 football fields, can deliver more than 2 million joules of ultraviolet laser energy in billionth-of-a-second pulses onto a target about the size of a pencil eraser.

The emphasis is mine, to highlight the point that this is a massive laser and facility. It’s like ten Walmart superstores stacked on top of each other. The lighting alone is likely taking tens of kilowatts, which could hypothetically be run for less than a minute on the energy gain from the fusion pop.  It would be fun to count all the megajoules that went into press coverage of the event!

Power Plant Energetics

Let’s connect the 3 MJ output to that of actual power plants, forgetting for a moment the tremendous energy loss represented in getting 3 MJ out from a 400 MJ input. A typical electrical power plant (nuclear, coal, etc.) delivers about 1 GW of electrical power. But it’s a heat engine operating at 30–40% thermodynamic efficiency. So it takes roughly 3 GW of thermal energy to export 1 GW as electricity. 3 GW is 3 GJ per second, or 3,000 MJ per second.

The same efficiency factor would apply to a putative fusion plant. The concept behind fusion power is that it’s just another thermal source—an excruciatingly elaborate way to boil water to make steam to drive a turbine to run a generator. So our 3 MJ would need to be replicated 1,000 times per second to amount to 3 GW.

Laser repetition rates can be all over the map. 1,000 Hz is not in itself unusually fast by any stretch. What is the repetition rate of the NIF laser? Handily, LLNL provides these statistics. The average since 2015 is 377 shots per year, with a high of 417 and a low of 327. That’s about a shot per day—or two on a good day. It’s only 100 million times shy of 1 kHz. Oh dear.


An interview of physicist Bob Rosner in the Bulletin of Atomic Scientists helpfully puts the NIF in context (it’s not about societal energy). In it, he reinforces some of what we’ve covered, and adds some financial detail.

This facility can do one shot a day; this is at slightly more than two megajoules (of output). For an energy source, it would have to do the same thing at least 10 times a second. If you ask, “Do the lasers exist that can do this?” Not in your dream. The pellet cost a bit over $100,000 to manufacture.

The 10 shots per second, I gather, is if the fusion yield could be improved by a couple orders of magnitude—approaching actual break-even. At $100,000 per (literal) pop, and even just ten shots per second, we’re talking a cool million dollars per second!

Let’s wave a magic wand for a minute and say that the 400 MJ input produced a 700 MJ output for a net of 300 MJ: 100 times the recent breakthrough. This accords with the ten shots per second mentioned above. What is the price of the delivered electricity? After thermodynamic inefficiency is accounted, we get 100 MJ out for $100,000 cost, or $1,000 per megajoule. We are accustomed to using the kilowatt-hour (kWh) as a measure of delivered energy, which is 3.6 MJ. The cost becomes, then, $3,600 per kWh. Typical electricity costs are in the neighborhood of $0.15–0.20 per kWh, so we’re dealing with a cost that is 20,000 times higher than nominal. And don’t forget, we used a magic wand to even get there. It’s closer to 2 million times more expensive currently, and—let’s not forget—as a net energy loser.

Granted, the research and development phase is not characteristic of operational costs. But try going to a venture capitalist and making the argument that you can trim costs to 0.005% of their current amount. Slam!

This massive reduction, incidentally, translates to a cost of $5 per pellet. I don’t care what mass-production slave labor you might dream of employing. A cryogenic hydrogen-ice target made to demanding precision specifications, containing deuterium and transmuted lithium (to make tritium) is not going to cost $5. You lost me at cryogenic. Also, they would have made many pellets by now and I’m sure don’t relish spending $100,000 each. If they’re clever enough to accomplish fusion, they would be clever enough to have already reduced costs dramatically if it were straightforward.

Fusion Efficiency

Here’s the part where I earn my keep as a physicist translating technical matters. I found details about the NIF targets in a 2017 paper by Bernard Koziokiemski et al. The abstract alone clarifies much. The target is a shell of hydrogen ice 75 μm thick on a 1 mm radius sphere, cooled below 19 K. Pause for a moment to contemplate the challenges that would be involved if trying to maintain the targets at such low temperatures in a 3 GW power plant “furnace” environment.

Hydrogen ice has a density of 86 kg/m3, which in the specified volume (10−9 m3) translates to 5×1019 lattice sites (nuclei/atoms). Deuterium/tritium ice has a higher density than hydrogen ice, but the atomic spacing is unchanged so that the pure hydrogen calculation gives the correct number.

How many fusion events took place to crank out 3 MJ of energy? Each deuterium–tritium fusion event releases 17.6 MeV of energy, or 2.8×10−12 J. Calling this 3×10−12 J (among friends; makes for easy math), we find that we need 1018 fusion events to amount to 3 MJ. Each event involves 2 nuclei. We calculated above that the shell contains 50×1018 nuclei, meaning that 4% of them participated in fusion.

This event therefore produced a 4% yield. I’m actually very impressed! That’s nothing to sneeze at. The laser-induced implosion is very fast, very violent, and leaves lots of room for nuclei failing to “find” each other if not compressed almost flawlessly and symmetrically to sub-micron scale. Before doing the calculation, I might have guessed a yield orders-of-magnitude smaller.

So this news is both good and bad. Hats off for cracking into single-digit yield! But that leaves less room to improve. Even at 100% efficiency, we’d get just 25 times more energy out, or 75 MJ. That’s still not enough to pay for the price of admission (400 MJ, just for the laser part).

NIF Purpose

This avenue, therefore, seems painfully far away from achieving practical societal energy. Even 100% yield (for the present design) could not produce net energy. Even if it could produce net energy, the laser repetition rate is a million times too slow. And then, even if the laser could fire fast enough, the cost of each target is prohibitively high by over four orders-of-magnitude.

Then, we have a raft of practical considerations for turning an experimental facility into a functional power plant. No design exists at present to extract the heat produced at NIF. That’s not what it’s for—it wouldn’t make any sense to put effort in that direction.  Such a design would have the unenviable thermal challenge of delivering cryogenic targets into a hellfire-hot environment. For energy extraction, tokamak designs like ITER are less unsuitable.   In either case, all this to boil water. Bless their hearts.

But the NIF was never “about” societal energy. Its primary purpose is nuclear weapons research. This pesky thing called the nuclear test ban treaty means we can’t just go around detonating nuclear bombs whenever we feel like it. Surely we did not run out of South Pacific island paradises to blow to smithereens. The NIF allows study of matter at extremely high energy density. Other targets besides deuterium–tritium can be placed in the converging laser beams. Essentially, we can create the unbelievably hot conditions relevant to nuclear detonations in the safety of our own national lab.

Inertial confinement fusion (ICF) constitutes a small fraction of NIF’s laser shots. Most of the work is labeled HED for high-energy-density research. The people at NIF are under no false impression about the potential of this type of approach for generating societal energy. They know what they’re about. At the same time, why not poke? It certainly has some benefits in terms of public attention, translating to funding.

How Embarrassing

So what can we say about the public reaction to this news? Headlines in December gushed about the dawn of a new era of limitless energy. People got excited. Many of my students came away thinking it was basically a done deal—now just a matter of putting into practice. That’s how it works in entertainment: a genius breakthrough followed by immediate implementation free of complication. The emphasis is on human ingenuity, not on physical reality. In my experience, ideas are a dime-a-dozen. The hard part is coming up with an idea that can be practically brought to fruition.

I often encounter a disconnect on matters of this sort when interacting with people—whether about space colonization, fusion, renewable energy, or prospects for modernity’s continuation. I frequently find myself outnumbered. Why am I so negative about these things? The disconnect might have something to do with how information is received and processed. If all I had to go on were popular media accounts, word-of-mouth, and entertainment, I’d probably be similarly miscalibrated. But my background, training, experiences, and accomplishments enable an uncommon approach that is less dependent on what other people are saying, and more strongly tied to the underlying drivers. That’s not to say I’ll always have a more accurate take, but just that my process generally involves more independent thought and analysis than I suspect it does for most people.  I’m no fun at parties.

In any case, the public reaction to the fusion story tells me a lot about our collective psychology. To me, it speaks to a sense of desperation. I think people sense that the “bad news” side of the ledger is overcrowded of late, and it’s starting to dawn on people that the future could possibly be worse than the present. This causes a cognitive dissonance in that our cultural narrative is one of progress, growth, and innovation. How can these competing visions be squared? News of fusion has the effect of temporarily permitting people to shed the anxiety and embrace the dream all the more strongly. Words that come to mind are: embarrassing, pathetic, humiliating.

What if you see a movie star across the street, overcome by excitement as they stop, look at you, and wave enthusiastically. You, of course, wave back. They see you. They recognize you as special, just as you knew all along. Only, it then becomes apparent that their movie star fling (according to the tabloids) was passing behind you. Now how do you feel? How could you fall for it? That’s the question I find myself asking about the fusion hype. It’s so obviously far from relevant, how could we (and the media establishment) fall for it?

My suspicion is that it plays perfectly into our culture’s irrational hopes and dreams. We have a weak spot in our armor for things that sound too good to be true. We want to believe the narrative (mythology) that humans are exempt from all limits, and that our ingenuity will save the day every time. We want to believe that the movie star would adore us, if only they got the chance to meet us.  Instant besties!

Many in our culture truly believe in “the amazing future,” uncritically extrapolating our fossil-fueled joy ride into ever-more impressive innovations and technologies. Of course, we will someday roam the galaxy. Of course we will have warp drive (how else would we roam the galaxy?). Of course fusion is a necessary stepping stone on this path. It’s silly to imagine warp drive and teleportation without first cracking fusion. So societal fusion power has to happen, in their imaginations.

The problem is that such imaginings are not tethered to physical reality. They are driven by ideology, or I would say mythology. The physical reality is that we are living in an ecologically, evolutionarily untested paradigm that is very recent (on relevant timescales) and powered by patently unsustainable practices and resource use. The cost is rapid ecological degradation and global disruption to the biosphere. It seems quite clear that the track we are on does not lead to the stars, but to ignominious self-termination of this whacky mode called modernity. It simply does not add up, once the mythology is stripped away. The venture capitalist of nature is about to slam the door on our faces.

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39 days ago
Cambridge, London, Warsaw, Gdynia
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