Hello Sceptics
Today: A sheet of paper doing what a billion-dollar plant couldn't.
Coffee at the ready…
The Big Sip
A South Korean team coated a sheet of mulberry paper with carbon black, paired it with a hydrogel, and built a battery powered by pollution.
No external power. No subsidy. No fans the size of a house. Professor Ji-Soo Jang's group at Sungkyunkwan published the prototype in Energy & Environmental Science this February.
Watch whether anyone builds the first real-world pilot before 2027.
The voltage is tiny. The direction is the story.
Here’s Your Brew
The paper is real.
Korean calligraphers have used mulberry hanji for a thousand years — thin, strong, cheap enough to wrap a parcel in. Jang's group coated one side in carbon black and laid it against an asymmetrically dip-coated polyacrylamide hydrogel.
When NO₂ or CO₂ hits the paper, hydrogen bonds form with the hydrogel, ions shift across the electrical double layer, and direct current flows.
That's the whole device.
One cell delivers 0.8 volts and 55 microamps under a 50 ppm NO₂ stream.
Stack a handful in series and parallel, and you reach 3.8 volts and 140 microamps. Enough to run a low-draw environmental sensor.
Enough, in principle, to power a battery-free IoT node off the exhaust it's measuring.
For contrast, take the flagship plant the carbon-capture sector has been pointing to for years.
Climeworks' Mammoth in Iceland: 72 V-shaped collector units the size of shipping containers, over $1 billion raised, a nameplate of 36,000 tonnes a year.
In its first ten months of operation, Mammoth captured 105 tonnes — verified by third-party registry Puro Earth. Not 105,000.
One hundred and five.
Conventional point-source capture at industrial sites already runs $11–$63 a tonne.
The paper isn't trying to beat that on cost. It's trying to capture and earn at once, rather than capture and bill the taxpayer.
Washington pays up to $180 a tonne under the 45Q tax credit to bury carbon. Last October, the DOE pulled $47 million from ten DAC hub projects anyway.
The catch is concentration.
50 ppm NO₂ is far higher than anything you'd encounter outside, where readings are in the parts-per-billion range.
The paper's first home is where the gas is already thick:
Smokestacks, tunnel vents, factory exhaust.
Picture a sensor inside a chimney, powered by what it measures.
Powering Seoul off its own smog is a press-release fantasy.
Two Sides, One Mug
Pro: For the first time in years, a carbon capture story doesn't end with "...and the taxpayer pays the difference."
Con: Lab-scale voltages at elevated gas concentrations have a long, graveyard-paved history of never making it to deployment.
Our read: Sceptics get to keep their scepticism and take one quiet pleasure: somewhere in Suwon, a sheet of paper is doing better climate maths than a billion-dollar plant in Iceland.
Receipt of the Day
[Report] Royal Society of Chemistry — "Electrical power generation from asymmetric greenhouse gas capture" (Energy & Environmental Science, 2026, 19, 2149–2160)
Key finding: A single GCEG cell generates 0.8 V and 55 µA at 50 ppm NO₂, stackable to 3.8 V and 140 µA, driven by hydrogen-bond interactions between gases and a polyacrylamide hydrogel.
Why it matters: The peer-reviewed primary source. The paper is not a metaphor.
Spit Take
World's biggest carbon-capture plant, first ten months: 105 tonnes.
A sheet of paper, 2026: running a sensor on its own.
Extra Curricular Coffee Break Links
[Analysis] Michael Barnard — "The Mammoth Failure of Direct Air Capture" — Built for 36,000 tonnes a year. Captured 105 in its first ten months. The industry's humility test.
[Report] E&E News — "Direct air capture takes 'huge hit' in DOE funding cuts" — When subsidy-dependent climate tech loses its subsidy, cheaper alternatives stop being cute.
[Analysis] Green Fuel Journal — "Direct Air Capture: How DAC & Carbon Removal Markets Are Scaling in 2026" — The cost curve DAC has to ride. Spoiler: it's steep.
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