Carbon capture and storage: a reality check

Attosecond Electron Transport uses ultrafast lasers and single-cycle light pulses to drive tunneling in bowtie gold nanoantennas, enabling sub-femtosecond switching in optoelectronic nanostructures and surpassing picosecond silicon limits for next-gen computing.

Key Points

A light-driven method that manipulates electrons with ultrafast pulses to switch currents within attoseconds.

✅ Uses single-cycle light pulses to drive electron tunneling

✅ Achieves 600 attosecond current switching in nano-gaps

✅ Enables optoelectronic, plasmonic devices beyond silicon

When it comes to data transfer and computing, the faster we can shift electrons and conduct electricity the better – and scientists have just been able to transport electrons at sub-femtosecond speeds (less than one quadrillionth of a second) in an experimental setup.

The trick is manipulating the electrons with light waves that are specially crafted and produced by an ultrafast laser. It might be a long while before this sort of setup makes it into your laptop, but similar precision is seen in noninvasive interventions where targeted electrical stimulation can boost short-term memory for limited periods, and the fact they pulled it off promises a significant step forward in terms of what we can expect from our devices.

Right now, the fastest electronic components can be switched on or off in picoseconds (trillionths of a second), a pace that intersects with debates over 5G electricity use as systems scale, around 1,000 times slower than a femtosecond.

With their new method, the physicists were able to switch electric currents at around 600 attoseconds (one femtosecond is 1,000 attoseconds).

"This may well be the distant future of electronics," says physicist Alfred Leitenstorfer from the University of Konstanz in Germany. "Our experiments with single-cycle light pulses have taken us well into the attosecond range of electron transport."

Leitenstorfer and his colleagues were able to build a precise setup at the Centre for Applied Photonics in Konstanz. Their machinery included both the ability to carefully manipulate ultrashort light pulses, and to construct the necessary nanostructures, including graphene architectures, where appropriate.

The laser used by the team was able to push out one hundred million single-cycle light pulses every single second in order to generate a measurable current. Using nanoscale gold antennae in a bowtie shape (see the image above), the electric field of the pulse was concentrated down into a gap measuring just six nanometres wide (six thousand-millionths of a metre).

As a result of their specialist setup and the electron tunnelling and accelerating it produced, the researchers could switch electric currents at well under a femtosecond – less than half an oscillation period of the electric field of the light pulses.

Getting beyond the restrictions of conventional silicon semiconductor technology has proved a challenge for scientists, but using the insanely fast oscillations of light to help electrons pick up speed could provide new avenues for pushing the limits on electronics, as our power infrastructure is increasingly digitized and integrated with photonics.

And that's something that could be very advantageous in the next generation of computers: scientists are currently experimenting with the way that light and electronics could work together in all sorts of different ways, from noninvasive brain stimulation to novel sensors.

Eventually, Leitenstorfer and his team think that the limitations of today's computing systems could be overcome using plasmonic nanoparticles and optoelectronic devices, using the characteristics of light pulses to manipulate electrons at super-small scales, with related work even exploring electricity from snowfall under specific conditions.

"This is very basic research we are talking about here and may take decades to implement," says Leitenstorfer.

The next step is to experiment with a variety of different setups using the same principle. This approach might even offer insights into quantum computing, the researchers say, although there's a lot more work to get through yet - we can't wait to see what they'll achieve next.

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North Carolina Utility Arrears Crisis strains households and municipal budgets as COVID-19 cuts jobs; unpaid utility bills mount, shutoffs loom, and emergency aid, unemployment benefits, and CARES Act relief lag behind rising arrears across cities.

Key Points

A COVID-19 driven spike in unpaid utility bills, threatening households and municipal budgets as federal aid lapses.

✅ 1 million families behind on power, water, sewage bills

✅ $218M arrears accrued April to June, double last year

✅ Municipal utilities face shutoffs, budget shortfalls

As many as 1 million families in North Carolina have fallen behind on their electric, water and sewage bills, a sign of energy insecurity threatening residents and their cities with severe financial hardship unless federal lawmakers act to approve more emergency aid.

The trouble stems from the widespread economic havoc wrought by the coronavirus, which has left millions of workers out of a job and struggling to cover their monthly costs as some states moved to suspend utility shut-offs to provide relief. Together, they’ve been late or missed a total of $218 million in utility payments between April 1 and the end of June, according to data released recently by the state, nearly double the amount in arrears at this time last year.

In some cases, cities that own or operate their own utilities have been forced to absorb these losses, as some utilities reconnected customers to prevent harm, creating a dire situation in which the government’s attempt to save people from the financial brink instead has pushed municipal coffers to their own breaking point.

In Elizabeth City, N.C., for example, about 2,500 residents haven’t paid their electric bills on time, according to Richard Olson, the city manager. The late payments at one point proved so problematic that Olson said he calculated Elizabeth City wouldn’t have enough money to pay for its expenses in July. In response, city leaders requested and obtained a waiver from a statewide order, similar to New York’s disconnection moratorium, issued in March, that protects people from being penalized for their past-due utility bills.

The predicament has presented unique budget challenges throughout North Carolina, while illustrating the consequences of a cash crunch plaguing the entire country, where proposals such as a Texas electricity market bailout surfaced following severe grid stress. State and federal leaders have extended a range of coronavirus relief programs since March to try to help people through the pandemic. But the money is limited and restricted — and it’s not clear whether more help from Congress is on the way — creating a crisis in which the nation’s economic woes are outpacing some of the aid programs adopted to combat them.

“We are entering a phase where the utilities [may] be able to shut off power, but what was propping up people’s economic lives, the unemployment benefits and Cares Act support, won’t be there,” said Paul Meyer, the executive director of the North Carolina League of Municipalities.

White House, GOP in disarray over coronavirus spending plan as deadline nears on expiring emergency aid

The future of that safety-net support — and other federal aid — hangs in the balance as lawmakers returned to work this week in their final sprint ahead of the August recess. The White House and congressional leaders are split over the contours of the next coronavirus relief package, including the need to extend more aid to cities and states as some utilities have waived fees to help customers, and reauthorize an extra $600 in weekly unemployment payments that were approved as part of the Cares Act in March.

Outside Washington, workers, businesses and government officials nationwide have pleaded with federal lawmakers to renew or expand those programs. Last week, Roy Cooper, the Democratic governor of North Carolina, urged Congress to act swiftly and adopt a wide array of new federal spending, including proposals for DOE nuclear cleanup funding, stressing in a letter that the “actions you take in the next few weeks are vital to our ability to emerge from this crisis. ”

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India spot electricity prices surged on Q3 demand, lifting power tariffs in the spot market as discoms scrambled for supply; Sembcorp SGPL boosted PLF and short-term PPA realizations, benefiting from INR per kWh peaks.

Key Points

India spot electricity prices hit Q3 records amid demand spikes, lifting tariffs and aiding Sembcorp SGPL via PLF gains.

✅ Record 10.6 cents/kWh average; 15-minute peak 20.7 cents/kWh

✅ SGPL shifted output to short-term PPA at 7.3 cents/kWh

✅ PLF ramped above 90%, cutting core losses by 30-40%

Electricity prices in India, now the third-largest electricity producer globally, bolted to a record high of 10.6 cents/kWh (INR5.1/kWh) in Q3.

A jolt in Indian spot electricity prices could save Sembcorp Industries' Indian business from further losses, even though demand has occasionally slumped in recent years, UOB Kay Hian said.

The firm said spot electricity prices in India bolted to a record high of 10.6 cents/kWh (INR5.1/kWh) in Q3 and even hit a 15-minute peak of 20.7 cents/kWh (9.9/kWh). The spike was due to a power supply crunch on higher electricity demand from power distribution companies, alongside higher imported coal volumes as domestic supplies shrank.

As an effect, Sembcorp Industries' Sembcorp Gayatri Power Limited's (SGPL) losses of $26m in Q1 and $29m in Q2 could narrow down by as much as 30-40%.

On a net basis, SGPL will recognise a significantly higher electricity tariff in 3Q17. By tactically shutting down its Unit #3 for maintenance, Unit #4 effectively had its generation contracted out at the higher short-term PPA tariff of around 7.3 cents/kWh (Rs3.5/kWh).

SGPL also capitalised on the price spike in 3Q17 as it ramped up its plant load factor (PLF) to more than 90%.

“On the back of this, coupled with the effects of reduced finance costs, we expect SGPL’s 3Q17 quarterly core loss to shrink by 30-40% from previous quarters,” UOB Kay Hian said.

Whilst electricity prices have corrected to 7.1 cents/kWh (INR3.4/kWh), the firm said it could still remain elevated on structural factors, even as coal and electricity shortages ease nationwide.

Sembcorp Industries' India operations brought in a robust performance for Q3. PLF for Thermal Powertech Corporation India Limited (TPCIL) hit 91%, whilst it reached 73% for SGPL, echoing the broader trend of thermal PLF up across the sector.

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Middle Tennessee Power Outages disrupt 100,000+ customers as severe thunderstorms, straight-line winds, downed trees, and debris challenge Nashville crews, slow restoration amid COVID-19, and threaten more hail, flash flooding, and damaging gusts.

Key Points

Blackouts across Nashville after severe storms and winds, leaving customers without power and facing restoration delays.

✅ Straight-line winds 60-80 mph toppled trees and power lines

✅ 130,000+ customers impacted; some outages may last 1-2 weeks

✅ Restoration slowed by debris, COVID-19 protocols, and new storms

Some middle Tennessee residents could be without electricity for up to two weeks after strong thunderstorms swept through the area Sunday, knocking out power for more than 100,000 customers, a scale comparable to Los Angeles outages after a station fire.

"Straight line winds as high as 60-80 miles per hour knocked down trees, power lines and power polls, interrupting power to 130,000 of our 400,000+ customers," Nashville Electric said in a statement Monday. The utility said the outage was one of the largest on record, though Carolina power outages recently left a quarter-million without power as well.

"Restoration times will depend on individual circumstances. In some cases, power could be out for a week or two" as challenges related to coronavirus and the need for utilities adapt to climate change complicated crews' responses and more storms were expected, the statement said. "This is unfortunate timing on the heels of a tornado and as we deal with battling COVID-19."

Metropolitan Nashville and Davidson County Mayor John Cooper also noted that the power outages were especially inconvenient, a challenge similar to Hong Kong families without power during Typhoon Mangkhut, as people were largely staying home to slow the spread of coronavirus. He also pointed out that the storms came on the two month anniversary of the Nashville tornado that left at least two dozen people dead.

"Crews are working diligently to restore power and clear any debris in neighborhoods," Cooper said.

He said that no fatalities were reported in the county but sent condolences to Spring Hill, whose police department reported that firefighter Mitchell Earwood died during the storm due to "a tragic weather-related incident" while at his home and off duty. He had served with the fire department for 10 years.

The Metro Nashville Department of Public Works said it received reports of more than 80 downed trees in Davidson County.

Officials also warn that copper theft can be deadly when electrical infrastructure is damaged after storms.

The National Weather Service Nashville said a 72 mph wind gust was measured at Nashville International Airport — the fifth fastest on record.

The weather service warned that strong storms with winds of up to 75 mph, large hail, record-long lightning bolt potential seen in the U.S., and isolated flash flooding could hit middle Tennessee again Monday afternoon and night.

"Treat Severe Thunderstorm Warnings the same way you would Tornado Warnings and review storm safety tips before you JUST TAKE SHELTER," the NWS instructs. "70 mph is 70 mph whether it's spinning around in a circle or blowing in a straight line."

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California Wildfire Smoke Impact on Solar reduces photovoltaic output, as particulate pollution, soot, and haze dim sunlight and foul panels, cutting utility-scale generation and grid reliability across CAISO during peak demand and heatwaves.

Key Points

How smoke and soot cut solar irradiance and foul panels, slashing PV generation and straining CAISO grid operations.

✅ Smoke blocks sunlight; soot deposition reduces panel efficiency.

✅ CAISO reported ~30% drop versus July during peak smoke.

✅ Longer fire seasons threaten solar reliability and capacity planning.

Smoke from California’s unprecedented wildfires was so bad that it cut a significant chunk of solar power production in the state, even as U.S. solar generation rose in 2022 nationwide. Solar power generation dropped off by nearly a third in early September as wildfires darkened the skies with smoke, according to the US Energy Information Administration.

Those fires create thick smoke, laden with particles that block sunlight both when they’re in the air and when they settle onto solar panels. In the first two weeks of September, soot and smoke caused solar-powered electricity generation to fall 30 percent compared to the July average, according to the California Independent System Operator (CAISO), which oversees nearly all utility-scale solar energy in California, where wind and solar curtailments have been rising amid grid constraints. It was a 13.4 percent decrease from the same period last year, even though solar capacity in the state has grown about 5 percent since September 2019.

California depends on solar installations for nearly 20 percent of its electricity generation, and has more solar capacity than the next five US states trailing it combined as it works to manage its solar boom sustainably. It will need even more renewable power to meet its goal of 100 percent clean electricity generation by 2045, building on a recent near-100% renewable milestone that underscored the transition. The state’s emphasis on solar power is part of its long-term efforts to avoid more devastating effects of climate change. But in the short term, California’s renewables are already grappling with rising temperatures.

Two records were smashed early this September that contributed to the loss of solar power. California surpassed 2 million acres burned in a single fire season for the first time (1.7 million more acres have burned since then). And on September 15th, small particle pollution reached the highest levels recorded since 2000, according to the California Air Resources Board. Winds that stoked the flames also drove pollution from the largest fires in Northern California to Southern California, where there are more solar farms.

Smaller residential and commercial solar systems were affected, too, and solar panels during grid blackouts typically shut off for safety, although smoke was the primary issue here. “A lot of my systems were producing zero power,” Steve Pariani, founder of the solar installation company Solar Pro Energy Systems, told the San Mateo Daily Journal in September.

As the planet heats up, California’s fire seasons have grown longer, and blazes are tearing through more land than ever before, while grid operators are also seeing rising curtailments as they integrate more renewables. For both utilities and smaller solar efforts, wildfire smoke will continue to darken solar energy’s otherwise bright future, even as it becomes the No. 3 renewable source in the U.S. by generation.

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Polycrystalline Tin Selenide Thermoelectrics enable waste heat recovery with ZT 3.1, matching single crystals while cutting costs, powering greener car engines, industrial furnaces, and thermoelectric generators via p-type and emerging n-type designs.

Key Points

Low-cost tin selenide devices that turn waste heat into power, achieving ZT 3.1 and enabling p-type and n-type modules.

✅ Oxygen removal prevents heat-leaking tin oxide grain skins.

✅ Polycrystalline ingots match single-crystal ZT 3.1 at lower cost.

✅ N-type tin selenide in development to pair with p-type.

So-called thermoelectric generators turn waste heat into electricity without producing greenhouse gas emissions, providing what seems like a free lunch. But despite helping power the Mars rovers, the high cost of these devices has prevented their widespread use. Now, researchers have found a way to make cheap thermoelectrics that work just as well as the pricey kind. The work could pave the way for a new generation of greener car engines, industrial furnaces, and other energy-generating devices.

“This looks like a very smart way to realize high performance,” says Li-Dong Zhao, a materials scientist at Beihang University who was not involved with the work. He notes there are still a few more steps to take before these materials can become high-performing thermoelectric generators. However, he says, “I think this will be used in the not too far future.”

Thermoelectrics are semiconductor devices placed on a hot surface, like a gas-powered car engine or on heat-generating electronics using thin-film converters to capture waste heat. That gives them a hot side and a cool side, away from the hot surface. They work by using the heat to push electrical charges from one to the other, a process of turning thermal energy into electricity that depends on the temperature gradient. If a device allows the hot side to warm up the cool side, the electricity stops flowing. A device’s success at preventing this, as well as its ability to conduct electrons, feeds into a score known as the figure of merit, or ZT.

 Over the past 2 decades, researchers have produced thermoelectric materials with increasing ZTs, while related advances such as nighttime solar cells have broadened thermal-to-electric concepts. The record came in 2014 when Mercouri Kanatzidis, a materials scientist at Northwestern University, and his colleagues came up with a single crystal of tin selenide with a ZT of 3.1. Yet the material was difficult to make and too fragile to work with. “For practical applications, it’s a non-starter,” Kanatzidis says.

So, his team decided to make its thermoelectrics from readily available tin and selenium powders, an approach that, once processed, makes grains of polycrystalline tin selenide instead of the single crystals. The polycrystalline grains are cheap and can be heated and compressed into ingots that are 3 to 5 centimeters long, which can be made into devices. The polycrystalline ingots are also more robust, and Kanatzidis expected the boundaries between the individual grains to slow the passage of heat. But when his team tested the polycrystalline materials, the thermal conductivity shot up, dropping their ZT scores as low as 1.2.

In 2016, the Northwestern team discovered the source of the problem: an ultrathin skin of tin oxide was forming around individual grains of polycrystalline tin selenide before they were pressed into ingots. And that skin acted as an express lane for the heat to travel from grain to grain through the material. So, in their current study, Kanatzidis and his colleagues came up with a way to use heat to drive any oxygen away from the powdery precursors, leaving pristine polycrystalline tin selenide, whereas other devices can generate electricity from thin air using ambient moisture.

The result, which they report today in Nature Materials, was not only a thermal conductivity below that of single-crystal tin selenide but also a ZT of 3.1, a development that echoes nighttime renewable devices showing electricity from cold conditions. “This opens the door for new devices to be built from polycrystalline tin selenide pellets and their applications to be explored,” Kanatzidis says.

Getting through that door will still take some time. The polycrystalline tin selenide the team makes is spiked with sodium atoms, creating what is known as a “p-type” material that conducts positive charges. To make working devices, researchers also need an “n-type” version to conduct negative charges.

Zhao’s team recently reported making an n-type single-crystal tin selenide by spiking it with bromine atoms. And Kanatzidis says his team is now working on making an n-type polycrystalline version. Once n-type and p-type tin selenide devices are paired, researchers should have a clear path to making a new generation of ultra-efficient thermoelectric generators. Those could be installed everywhere from automobile exhaust pipes to water heaters and industrial furnaces to scavenge energy from some of the 65% of fossil fuel energy that winds up as waste heat. 

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