A very different, very clean energy source: thin air
A microbial organism pulls electricity from water in the air.
- Hidden in the mud along the banks of Washington D.C.'s Potomac River may be a profound new source of electricity.
- The microbe makes nanowires that produce a charge from water vapor in ordinary air.
- Already capable of powering small electronics, it appears that larger-scale power generation is within reach.
The mad rush is on for discovering clean and renewable forms of energy before it's too late. Turns out, researchers may have unknowingly had it in hand for decades. It's a sediment organism first found along the muddy shores of the Potomac River and reported in a letter to the journal Nature in 1987. It turns out the microbe produces electricity out of thin air, one resource we're unlikely to run out of. University of Massachusetts Amherst scientists have just revealed their development of a device for harvesting this electricity in Nature.
The amazing microbe
Image source: Anna Klimes and Ernie Carbone, UMass Amherst/Wikipedia
The rod-shaped microbe, Geobacter sulfurreducens is, as its name implies, a member of the Geobacter genus, a group referred to as "electrigens" for their known ability to generate an electrical charge. It was UMass Amherst microbiologist Derek Lovley who found and wrote about the microbe in the late 80s.
It was also Lovlley's lab that discovered the microbe has a talent for producing electrically conductive protein nanowires, and his lab recently developed a new Geobacter strain that could produce them more rapidly and inexpensively. "We turned E. coli into a protein nanowire factory," Lovley says. What this means, he says, is that "With this new scalable process, protein nanowire supply will no longer be a bottleneck to developing these applications."
Enter electrical engineer Jun Yao, also of UMass Amherst. His specialty had been engineering electronic devices using silicon nanowires. The two decided to work together to see if they could turn Geobacter's protein nanowires into something useful.
Artisit's conception of the duo's Air-gen, with Geobacter's charge-producing nanowires imagined beneath the device.
Image source: UMass Amherst/Yao and Lovley labs
The fruit of their collaboration is a device they call "Air-gen." It employs a thin film of Geobacter nanowires less than 10 microns thick resting on an electrode. Another, smaller electrode sits on top of the film. The film collects, or adsorbs, water vapor, and its surface chemistry and conductivity produce a charge that passes between the two electrodes through the fine gaps between individual nanowires.
Yao's doctoral student Xiaomeng Liu recalls, "I saw that when the nanowires were contacted with electrodes in a specific way the devices generated a current. I found that that exposure to atmospheric humidity was essential and that protein nanowires adsorbed water, producing a voltage gradient across the device."
Says Yao, "We are literally making electricity out of thin air." The Air-gen generates clean energy 24/7. "It's the most amazing and exciting application of protein nanowires yet." The two see their new technology as being non-polluting, renewable, and low cost- with distinct advantages over other developing energy sources such as solar and wind for at least one big reason, "it even works indoors" notes Lovley.
Something in the air
Air-gen producing electrical current
Image source: UMass Amherst/Yao and Lovley labs
At this point, Air-gen generates "a sustained voltage of around 0.5 volts across a 7-micrometre-thick film, with a current density of around 17 microamperes per square centimeter," enough power to run small electronics. Chaining together several Air-gen units produces even more voltage. The device marks an obvious advance beyond other existing moisture-based energy-harvesting devices that are capable only of intermittent bursts of electricity that last less than 50 seconds.
Lovley and Yao plan Air-gen modifications that will allow Air-gen to replace the batteries used in electronic wearables — smart watches and other health and fitness devices — providing self-renewing energy. They also expect it to soon provide power for mobile phones the user will no longer need to recharge.
"The ultimate goal," says Yao, "is to make large-scale systems. For example, the technology might be incorporated into wall paint that could help power your home. Or, we may develop stand-alone air-powered generators that supply electricity off the grid. Once we get to an industrial scale for wire production, I fully expect that we can make large systems that will make a major contribution to sustainable energy production."
Clearly excited by the work so far, Yao says, "This is just the beginning of new era of protein-based electronic devices."
To create wiser adults, add empathy to the school curriculum.
- Stories are at the heart of learning, writes Cleary Vaughan-Lee, Executive Director for the Global Oneness Project. They have always challenged us to think beyond ourselves, expanding our experience and revealing deep truths.
- Vaughan-Lee explains 6 ways that storytelling can foster empathy and deliver powerful learning experiences.
- Global Oneness Project is a free library of stories—containing short documentaries, photo essays, and essays—that each contain a companion lesson plan and learning activities for students so they can expand their experience of the world.
Philosophers like to present their works as if everything before it was wrong. Sometimes, they even say they have ended the need for more philosophy. So, what happens when somebody realizes they were mistaken?
Sometimes philosophers are wrong and admitting that you could be wrong is a big part of being a real philosopher. While most philosophers make minor adjustments to their arguments to correct for mistakes, others make large shifts in their thinking. Here, we have four philosophers who went back on what they said earlier in often radical ways.
Numerous U.S. Presidents invoked the Insurrection Act to to quell race and labor riots.
- U.S. Presidents have invoked the Insurrection Act on numerous occasions.
- The controversial law gives the President some power to bring in troops to police the American people.
- The Act has been used mainly to restore order following race and labor riots.
It looks like a busy hurricane season ahead. Probably.
- Before the hurricane season even started in 2020, Arthur and Bertha had already blown through, and Cristobal may be brewing right now.
- Weather forecasters see signs of a rough season ahead, with just a couple of reasons why maybe not.
- Where's an El Niño when you need one?
Welcome to Hurricane Season 2020. 2020, of course, scoffs at this calendric event much as it has everything else that's normal — meteorologists have already used up the year's A and B storm names before we even got here. And while early storms don't necessarily mean a bruising season ahead, forecasters expect an active season this year. Maybe storms will blow away the murder hornets and 13-year locusts we had planned.
NOAA expects a busy season
According to NOAA's Climate Prediction Center, an agency of the National Weather Service, there's a 60 percent chance that we're embarking upon a season with more storms than normal. There does, however, remain a 30 percent it'll be normal. Better than usual? Unlikely: Just a 10 percent chance.
Where a normal hurricane season has an average of 12 named storms, 6 of which become hurricanes and 3 of which are major hurricanes, the Climate Prediction Center reckons we're on track for 13 to 29 storms, 6 to 10 of which will become hurricanes, and 3 to 6 of these will be category 3, 4, or 5, packing winds of 111 mph or higher.
What has forecasters concerned are two factors in particular.
This year's El Niño ("Little Boy") looks to be more of a La Niña ("Little Girl"). The two conditions are part of what's called the El Niño-Southern Oscillation (ENSO) cycle, which describes temperature fluctuations between the ocean and atmosphere in the east-central Equatorial Pacific. With an El Niño, waters in the Pacific are unusually warm, whereas a La Niña means unusually cool waters. NOAA says that an El Niño can suppress hurricane formation in the Atlantic, and this year that mitigating effect is unlikely to be present.
Second, current conditions in the Atlantic and Caribbean suggest a fertile hurricane environment:
- The ocean there is warmer than usual.
- There's reduced vertical wind shear.
- Atlantic tropical trade winds are weak.
- There have been strong West African monsoons this year.
Here's NOAA's video laying out their forecast:
ArsTechnica spoke to hurricane scientist Phil Klotzbach, who agrees generally with NOAA, saying, "All in all, signs are certainly pointing towards an active season." Still, he notes a couple of signals that contradict that worrying outlook.
First off, Klotzbach notes that the surest sign of a rough hurricane season is when its earliest storms form in the deep tropics south of 25°N and east of the Lesser Antilles. "When you get storm formations here prior to June 1, it's typically a harbinger of an extremely active season." Fortunately, this year's hurricanes Arthur and Bertha, as well as the maybe-imminent Cristobal, formed outside this region. So there's that.
Second, Klotzbach notes that the correlation between early storm activity and a season's number of storms and intensities, is actually slightly negative. So while statistical connections aren't strongly predictive, there's at least some reason to think these early storms may augur an easy season ahead.
Image source: NOAA
Batten down the hatches early
If 2020's taught us anything, it's how to juggle multiple crises at once, and layering an active hurricane season on top of SARS-CoV-2 — not to mention everything else — poses a special challenge. Warns Treasury Secretary Wilbur Ross, "As Americans focus their attention on a safe and healthy reopening of our country, it remains critically important that we also remember to make the necessary preparations for the upcoming hurricane season." If, as many medical experts expect, we're forced back into quarantine by additional coronavirus waves, the oceanic waves slamming against our shores will best be met by storm preparations put in place in a less last-minute fashion than usual.
Ross adds, "Just as in years past, NOAA experts will stay ahead of developing hurricanes and tropical storms and provide the forecasts and warnings we depend on to stay safe."
Let's hope this, at least, can be counted on in this crazy year.
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