Isegoria

Geothermal offers a virtually limitless, always-on source of emissions-free heat and electricity:

If the US could capture just 2% of the thermal energy available two to six miles beneath its surface, it could produce more than 2,000 times the nation’s total annual energy consumption.

But because of geological constraints, high capital costs and other challenges, we barely use it at all: today it accounts for 0.4% of US electricity generation.

To date, developers of geothermal power plants have largely been able to tap only the most promising and economical locations, like this stretch of Nevada. They’ve needed to be able to drill down to porous, permeable, hot rock at relatively low depths. The permeability of the rock is essential for enabling water to move between two human-drilled wells in such a system, but it’s also the feature that’s often missing in otherwise favorable areas.

Starting in the early 1970s, researchers at Los Alamos National Laboratory began to demonstrate that we could engineer our way around that limitation. They found that by using hydraulic fracturing techniques similar to those now employed in the oil and gas industry, they could create or widen cracks within relatively solid and very hot rock. Then they could add in water, essentially engineering radiators deep underground.

Such an “enhanced” geothermal system then basically works like any other, but it opens the possibility of building power plants in places where the rock isn’t already permeable enough to allow hot water to circulate easily. Researchers in the field have argued for decades that if we drive down the cost of such techniques, it will unlock vast new stretches of the planet for geothermal development.

A noted MIT study in 2006 estimated that with a $1 billion investment over 15 years, enhanced geothermal plants could produce 100 gigawatts of new capacity on the grid by 2050, putting it into the same league as more popular renewable sources. (By comparison, about 135 gigawatts of solar capacity and 140 gigawatts of wind have been installed across the US.)

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Creating fractures in rocks with low permeability means that the water in the system can’t easily leak out into other areas. Consequently, if you close off the well system and keep pumping in water, you can build up mechanical pressure within the system, as the fractured rock sections push against the earth.

“The fractures are able to dilate and change shape, almost like balloons,” Norbeck says.

That pressure can then be put to use. In a series of modeling experiments, Fervo found that once the valve was opened again, those balloons effectively deflated, the flow of water increased, and electricity generation surged. If they “charged it” for days, by adding water but not letting it out, it could then generate electricity for days.

Researchers at Purdue have developed HADAR, or heat-assisted detection and ranging:

Because thermal waves constantly scatter, infrared cameras capture “ghostlike” images with no depth or texture:

For their experiment, the researchers chose an outdoor space in a marshy area, far from roads and urban illumination. They collected thermal images in the infrared spectrum across almost 100 different frequencies. And just as each pixel in RGB images is encoded by three visible frequencies (R for red, G for green, B for blue), each pixel in the experiment was labeled with three thermal physics attributes, TeX—temperature (T), material fingerprint or emissivity (e), and texture or surface geometry (X). “T and e are reasonably well understood, but the crucial insight about texture is actually in X,” says Jacob. “X is really the many little suns in your scene that’s illuminating your specific area of interest.”

The researchers fed all the collected TeX information into a machine-learning algorithm to generate images with depth and texture. They used what they call TeX decomposition to untangle temperature and emissivity, and recover texture from the heat signal. The decluttered T, e, and X attributes were then used to resolve colors in terms of hue, saturation, and brightness in the same way humans see color. “At nighttime, in pitch darkness, our accuracy was the same when we came back in the daytime and did the ranging and detection with RGB cameras,” Jacob says.

The biggest advantage of HADAR is that it is passive, Jacob adds. “Which means you don’t have to illuminate the scene with a laser, sound waves, or electromagnetic waves. Also, in active approaches like lidar, sonar, or radar, if there are many agents in the scene, there can be a lot of crosstalk between them.”

As a new technology, HADAR is in a fairly nascent stage, Jacob says. At present, data collection requires almost a minute. By comparison, an autonomous vehicle driving at night, for example, would need to image its surroundings in milliseconds. Also, the cameras required for data collection are bulky, pricey, and power hungry: “Great for a scientific demonstration, but not really for kind of widespread adoption,” according to Jacob. The researchers are currently working on these problems, and Jacob predicts another few years of research will be directed to address them.

Misha Saul reviews Simon Winchester‘s Exactly: How Precision Engineers Created the Modern World, published in the US as The Perfectionists: How Precision Engineers Created the Modern World, with an introduction that makes the case for getting the audiobook:

For a British analogy, Winchester is a kind of David Attenborough of the engineering world. Reading the audiobook himself, he shares the same gentle British tone of old-worldliness and authority, unveiling the story of man’s machine world just for you.

Initially, he says, the story of precision and mechanisation is indistinguishable from an ode to Britain:

We are acquainted with leading figures of the Industrial Revolution, the minds behind the steam engine, the standardised screw, locks and pulleys and more, that preceded and then fed the British Empire’s zenith and allowed her shipyards to support the navy that once ruled the world. Even after her zenith, Britain birthed the jet engine (arguably jointly with Germany2). (Exactly makes for a wonderful companion to James Dyson’s memoir Invention: A Life, Dyson being a British descendent of this British tradition of tinkering and invention.) Some time in the early 20th century (and in some respects much earlier) the Americans pick up the baton in manufacturing and technology. Where the Rolls-Royce was the epitome of precision manufacturing no expenses spared, Henry Ford brought the assembly line and mass manufacturing to the world. And where it was a plucky general who first proposed and demonstrated the power of interchangeable components in a French dungeon,3 the French Revolution put a halt to that. But it was Thomas Jefferson, witness to the experiment, who brought it to the New World and to the gun manufacturers of New England. And it is the Hubble telescope — that American fountain of knowledge — whose first $2bn iteration was ruined by a lens manufacturer who was out by a mere 1/50th of a human hair. Winchester ends his book in Japan, the Mecca of precision engineering, in a charming meditation on the Japanese blend of venerable human craftsmanship and the power of humanless manufacturing.

(Hat tip to Byrne Hobart.)

While carrying out work to check the risk of firedamp pockets in the abandoned mines of the Lorraine region in May, FDE discovered a large deposit of natural hydrogen:

For years, researchers and businesses in the private sector have been looking for rare natural hydrogen, otherwise known as native or white hydrogen, due to its potential as a clean and renewable energy source.

“If confirmed, this would be the largest potential natural hydrogen discovered to date in Europe,” Philippe de Donato, co-director of research at the GeoRessouces laboratory at the University of Lorraine, told France 3 Grand-Est at the end of May.

Indeed, it is believed that the Lorraine basin could contain 46 million tonnes of natural hydrogen — equivalent to half the world’s current hydrogen production — and enough to contribute to the EU’s decarbonisation objectives significantly.

Natural hydrogen is naturally present in the Earth’s crust and mantle, explains Isabelle Moretti, a researcher at the University of Pau and the Pays de l’Adour. It can be found in several places: “at ocean ridges, in the mountains with ophiolites, remnants of ancient oceanic rocks, but also in iron-rich rocks,” she said in an interview with L’Usine Nouvelle in June 2021.

The resource, which can be harnessed when it degases on the earth’s surface or when extracted with boreholes, has been on scientists’ radars for some time. But a broader interest in the resource arose as world nations sought to replace fossil gas with a clean-burning fuel.

Unlike hydrogen produced from natural gas or electrolysis, its natural counterpart requires no water and little energy to extract while taking up very little land.

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Indeed, the Earth continuously produces natural hydrogen through chemical reactions that are mainly related to oxidation of ferrous iron minerals.

All these advantages make natural hydrogen a much cheaper resource than hydrogen produced from electrolysis. The price of natural hydrogen is estimated at €1 per kilo, while renewable hydrogen currently reaches €6, according to a position paper published in February at the request of the European Commission by the Earth2 initiative, a French body bringing together industry and research groups.

Researchers from UConn, Columbia University, and Brookhaven National Lab have created a material lighter and stronger than steel from two unlikely components:

Lee and colleagues report that by building a structure out of DNA and then coating it with glass, they have created a very strong material with very low density. Glass might seem a surprising choice, as it shatters easily. However, glass usually shatters because of a flaw – such as a crack, scratch, or missing atoms – in its structure. A flawless cubic centimeter of glass can withstand 10 tons of pressure, more than three times the pressure that imploded the Oceangate Titan submersible near the Titanic last month.

It’s very difficult to create a large piece of glass without flaws. But the researchers knew how to make very small flawless pieces. As long as the glass is less than a micrometer thick, it’s almost always flawless. And since the density of glass is much lower than metals and ceramics, any structures made of flawless nano-sized glass should be strong and lightweight.

The team created a structure of self-assembling DNA. Almost like Magnatiles, pieces of DNA of specific lengths and chemistry snapped themselves together into a skeleton of the material. Imagine the frame of a house or building, but made of DNA.

Oleg Gang and Aaron Mickelson, nanomaterials scientists at Columbia University and Brookhaven’s Center for Functional Nanomaterials, then coated the DNA with a very thin layer of glass-like material only a few hundred atoms thick. The glass only just coated the strands of DNA, leaving a large part of the material volume as empty space, much like the rooms within a house or building.

The DNA skeleton reinforced the thin, flawless coating of glass making the material very strong, and the voids comprising most of the material’s volume made it lightweight. As a result, glass nanolattice structures are four times higher in strength but five times lower in density than steel. This unusual combination of lightweight and high strength has never been achieved before.

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The team is currently working with the same DNA structure but substituting even stronger carbide ceramics for glass. They have plans to experiment with different DNA structures to see which makes the material strongest.

Researchers at the RIKEN Center for Emergent Matter Science (CEMS) in Japan have found a simple and affordable way to store ammonia :

For its current use, ammonia is stored in pressure-resistant containers after liquefying it at temperatures of -27 Fahrenheit (-33 degrees Celsius).

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Kawamoto’s team found that the perovskite ethyl ammonium lead iodide (EAPbI3) reacts with ammonia at room temperature and pressure to make lead iodide hydroxide, or Pb(OH)I. Ethyl ammonium lead iodide has a one-dimensional columnar structure but, after reacting with ammonia, forms a two-dimensional layered structure.

Ammonia is a highly corrosive gas, but the chemical reaction with the perovskite allows for its safe storage that does not need any special equipment to store it either. The retrieval process is also very straightforward. Under vacuum, ethyl ammonium lead iodide can be heated to 122 Fahrenheit (50 degrees Celsius) to release ammonia gas.

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The perovskite-ammonia reaction is fully reversible, and the perovskite can be reused to store ammonia again after retrieval is completed. Interestingly, the perovskite also changes color to white when it stores ammonia and returns to its original yellow after ammonia is retrieved. Scientists can exploit this feature to make color-based sensors to determine the amount of ammonia stored in the perovskite.

Hydrogen fuel cells have found their groove, IEEE Spectrum reports:

Now scientists have found that adding grooves to PEM fuel cells can improve the performance of these devices by up to 50 percent compared with state-of-the-art conventional electrodes under standard operating conditions.

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Conventional PEM fuel cell electrodes are composed of a carbon-supported platinum catalyst and ion-conducting polymers known as ionomers, which are mixed in an ink slurry and deposited on a membrane or other structure as a porous electrode. This creates a random electrode structure with a complex, mazelike network of narrow pores that limits the flow within the fuel cell. This structure has largely stayed the same for more than 30 years, the researchers note.

In contrast, the new electrodes feature catalyst ridges loaded with ionomers separated by empty grooves. The ridges improve proton transport, while the grooves simultaneously help oxygen flow.

In conventional PEM fuel cell electrodes, a high ionomer content may enhance proton transport, but it typically also limits oxygen flow. By separating proton and oxygen flow along grooves and ridges, the new electrodes help improve the transport of both. This also helps keep reaction rates uniform in the fuel cell, boosting catalyst performance.

The scientists fabricated the new electrodes by depositing a mixture of carbon-supported platinum catalyst and ionomer in a patterned silicon template, followed by a transfer to a membrane made of the common polymer electrolyte known as Nafion. They experimented with electrodes with grooves 1 to 2 micrometers wide, and had grooves repeat across the electrodes every 3 to 6 µm. The narrower the grooves and the shorter the distances between them, the better the performance.

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The best-performing grooved electrodes were also significantly more durable than regular electrodes, displaying 170 percent higher current density after 500 cycles of activity. The researchers note that pores in conventional electrodes collapse over time due to corrosion, hampering their performance. By contrast, the grooved electrode structures remained relatively intact.