Pakistans PEPCO suffers huge power shortfall

Near-Field Thermophotovoltaics captures radiated energy across a nanoscale gap, using thin-film photovoltaic cells and indium gallium arsenide to boost power density and efficiency, enabling compact Army portable power from emitters via radiative heat transfer.

Key Points

A nanoscale TPV method capturing near-field photons for higher power density at lower emitter temperatures.

✅ Nanoscale gap boosts radiative transfer and usable photon flux

✅ Thin-film InGaAs cells recycle sub-band-gap photons via reflector

✅ Achieved ~5 kW/m2 power density with higher efficiency

With the addition of sensors and enhanced communication tools, providing lightweight, portable power has become even more challenging, with concepts such as power from falling snow illustrating how diverse new energy-harvesting approaches are. Army-funded research demonstrated a new approach to turning thermal energy into electricity that could provide compact and efficient power for Soldiers on future battlefields.

Hot objects radiate light in the form of photons into their surroundings. The emitted photons can be captured by a photovoltaic cell and converted to useful electric energy. This approach to energy conversion is called far-field thermophotovoltaics, or FF-TPVs, and has been under development for many years; however, it suffers from low power density and therefore requires high operating temperatures of the emitter.

The research, conducted at the University of Michigan and published in Nature Communications, demonstrates a new approach, where the separation between the emitter and the photovoltaic cell is reduced to the nanoscale, enabling much greater power output than what is possible with FF-TPVs for the same emitter temperature.

This approach, which enables capture of energy that is otherwise trapped in the near-field of the emitter is called near-field thermophotovoltaics or NF-TPV and uses custom-built photovoltaic cells and emitter designs ideal for near-field operating conditions, alongside emerging smart solar inverters that help manage conversion and delivery.

This technique exhibited a power density almost an order of magnitude higher than that for the best-reported near-field-TPV systems, while also operating at six-times higher efficiency, paving the way for future near-field-TPV applications, including remote microgrid deployments in extreme environments, according to Dr. Edgar Meyhofer, professor of mechanical engineering, University of Michigan.

"The Army uses large amounts of power during deployments and battlefield operations and must be carried by the Soldier or a weight constrained system," said Dr. Mike Waits, U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "If successful, in the future near-field-TPVs could serve as more compact and higher efficiency power sources for Soldiers as these devices can function at lower operating temperatures than conventional TPVs."

The efficiency of a TPV device is characterized by how much of the total energy transfer between the emitter and the photovoltaic cell is used to excite the electron-hole pairs in the photovoltaic cell, where insights from near-light-speed conduction research help contextualize performance limits in semiconductors. While increasing the temperature of the emitter increases the number of photons above the band-gap of the cell, the number of sub band-gap photons that can heat up the photovoltaic cell need to be minimized.

"This was achieved by fabricating thin-film TPV cells with ultra-flat surfaces, and with a metal back reflector," said Dr. Stephen Forrest, professor of electrical and computer engineering, University of Michigan. "The photons above the band-gap of the cell are efficiently absorbed in the micron-thick semiconductor, while those below the band-gap are reflected back to the silicon emitter and recycled."

The team grew thin-film indium gallium arsenide photovoltaic cells on thick semiconductor substrates, and then peeled off the very thin semiconductor active region of the cell and transferred it to a silicon substrate, informing potential interfaces with home battery systems for distributed use.

All these innovations in device design and experimental approach resulted in a novel near-field TPV system that could complement distributed resources in virtual power plants for resilient operations.

"The team has achieved a record ~5 kW/m2 power output, which is an order of magnitude larger than systems previously reported in the literature," said Dr. Pramod Reddy, professor of mechanical engineering, University of Michigan.

Researchers also performed state-of-the-art theoretical calculations to estimate the performance of the photovoltaic cell at each temperature and gap size, informing hybrid designs with backup fuel cell solutions that extend battery life, and showed good agreement between the experiments and computational predictions.

"This current demonstration meets theoretical predictions of radiative heat transfer at the nanoscale, and directly shows the potential for developing future near-field TPV devices for Army applications in power and energy, communication and sensors," said Dr. Pani Varanasi, program manager, DEVCOM ARL that funded this work.

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PG&E Public Safety Power Shutoff curbs wildfire risk amid high winds, triggering California outages across Northern California and Bay Area counties; grid safety measures, outage maps, campus closures, and restoration timelines guide residents and businesses.

Key Points

A preemptive outage program by PG&E to reduce wildfire ignition during extreme wind events in California.

✅ Cuts power during red flag, high wind, dry fuel conditions

✅ Targets Northern California, Bay Area counties at highest risk

✅ Restoration follows inspections, weather all-clear, hazard checks

California utility Pacific Gas and Electric Co. (PG&E) has cut off power supply to hundreds of thousands of residents in Northern and Central California as a precaution to possible breakout of wildfires, a move examined in reasons for shutdowns by industry observers.

PG&E confirmed that about 513,000 customers in many counties in Northern California, including Napa, Sierra, Sonoma and Yuba, were affected in the first phase of Public Safety Power Shutoff, a preemptive measure it took to prevent wildfires believed likely to be triggered by strong, dry winds.

The utility said the decision to shut off power was, amid ongoing debate over nuclear's status in California, "based on forecasts of dry, hot and windy weather including potential fire risk."

"This weather event will last through midday Thursday, with peak winds forecast from Wednesday morning through Thursday morning and reaching 60 mph (about 96 km per hour) to 70 mph (about 112 km per hour) at higher elevations," it said, while abroad National Grid warnings about short supply have highlighted parallel reliability concerns.

PG&E noted that about 234,000 residents in mostly counties of San Francisco Bay Area such as Alameda, Alpine, Contra Costa, San Mateo and Santa Clara were impacted in the second phase of the power shutoff, as the state considers power plant closure delays with potential grid impacts, that began around noon in Wednesday.

The unprecedented power outages sweeping across Northern California has darkened homes and forced schools and business to close, even as the UK paused an emergency energy plan amid its own supply concerns.

University of California, Berkeley canceled all classes for Wednesday due to expected campus power loss over the next few days.

The university said it has received notice from PG&E, as China's power woes cloud U.S. solar supplies that could aid resilience, that "most of the core campus will be without power" possibly for 48 hours.

A freshman at California State University San Jose told Xinhua that their classes were canceled Wednesday as the campus was running out of power.

"I had to go home because even our dormitory went without electricity," the student added.

However, PG&E noted in an updated statement Wednesday night that only 4,000 customers would be affected in the third phase being considered for Kern County in Central California, compared to an earlier forecast of 43,000 people who would experience power outage.

The PG&E power shutoff was the largest preemptive measure ever taken to prevent wildfires in the state's history, and it comes as clean power grows while fossil declines across California's grid, highlighting broader transition challenges.

The San Francisco-based California utility was held responsible for poor management of its power lines that sparked fatal wildfires in Northern California and killed 86 people last year in what was called Camp Fire, the single-deadliest wildfire in California's history.

Several lawsuits and other requests for compensation from wildfire victims that amounted to billions of U.S. dollars forced the embattled the company to claim bankruptcy protection early this year.

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IAEA Nuclear Reactor Simulators enable virtual nuclear power plant training on IPWR/PWR systems, load-following operations, baseload dynamics, and turbine coupling, supporting advanced reactor education, flexible grid integration, and low-carbon electricity skills development during remote learning.

Key Points

IAEA Nuclear Reactor Simulators are tools for training on reactor operations, safety, and flexible power management.

✅ Simulates IPWR/PWR systems with real-time parameter visualization.

✅ Practices load-following, baseload, and grid flexibility scenarios.

✅ Supports remote training on safety, controls, and turbine coupling.

Students and professionals in the nuclear field are making use of learning opportunities during lockdown made necessary by the Covid-19 pandemic, drawing on IAEA low-carbon electricity lessons for the future.

Requests to use the International Atomic Energy Agency’s (IAEA’s) basic principle nuclear reactor simulators have risen sharply in recent weeks, IAEA said on 1 May, as India takes steps to get nuclear back on track. New users will have the opportunity to learn more about operating them.

“This suite of nuclear power plant simulators is part of the IAEA education and training programmes on technology development of advanced reactors worldwide. [It] can be accessed upon request by interested parties from around the world,” said Stefano Monti, head of the IAEA’s Nuclear Power Technology Development Section.

Simulators include several features to help users understand fundamental concepts behind the behaviour of nuclear plants and their reactors. They also provide an overview of how various plant systems and components work to power turbines and produce low-carbon electricity, while illustrating roles beyond electricity as well.

In the integral pressurised water reactor (IPWR) simulator, for instance, a type of advanced nuclear power design, users can navigate through several screens, each containing information allowing them to adjust certain variables. One provides a summary of reactor parameters such as primary pressure, flow and temperature. Another view lays out the status of the reactor core.

The “Systems” screen provides a visual overview of how the plant’s main systems, including the reactor and turbines, work together. On the “Controls” screen, users can adjust values which affect reactor performance and power output.

This simulator provides insight into how the IPWR works, and also allows users to see how the changes they make to plant variables alter the plant’s operation. Operators can also perform manoeuvres similar to those that would take place in the course of real plant operations e.g. in load following mode.

“Currently, most nuclear plants operate in ‘baseload’ mode, continually generating electricity at their maximum capacity. However, there is a trend of countries, aligned with green industrial revolution strategies, moving toward hybrid energy systems which incorporate nuclear together with a diverse mix of renewable energy sources. A greater need for flexible operations is emerging, and many advanced power plants offer standard features for load following,” said Gerardo Martinez-Guridi, an IAEA nuclear engineer who specialises in water-cooled reactor technology.

Prospective nuclear engineers need to understand the dynamics of the consequences of reducing a reactor’s power output, for example, especially in the context of next-generation nuclear systems and emerging grids, and simulators can help students visualise these processes, he noted.

“Many reactor variables change when the power output is adjusted, and it is useful to see how this occurs in real-time,” said Chirayu Batra, an IAEA nuclear engineer, who will lead the webinar on 12 May.

“Users will know that the operation is complete once the various parameters have stabilised at their new values.”

Observing and comparing the parameter changes helps users know what to expect during a real power manoeuvre, he added.

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Texas wholesale electricity price spike disrupts ERCOT markets as Griddy and other retail energy providers face surge pricing; customers confront spot market exposure, fixed-rate plan switching, demand response appeals, and deep-freeze grid constraints across Texas.

Key Points

An extreme ERCOT market surge sending real-time rates to caps, exposing Griddy users and driving provider-switch pleas.

✅ Wholesale index plans pass through $9,000/MWh scarcity pricing.

✅ Retailers urge switching; some halt enrollments amid volatility.

✅ Demand response incentives and conservation pleas reduce load.

Some retail power companies in Texas are making an unusual plea to their customers amid a winter storm that has sent electricity prices skyrocketing: Please, leave us.

Power supplier, Griddy, told all 29,000 of its customers that they should switch to another provider as spot electricity prices soared to as high as $9,000 a megawatt-hour. Griddy’s customers are fully exposed to the real-time swings in wholesale power markets, so those who don’t leave soon will face extraordinarily high electricity bills.

“We made the unprecedented decision to tell our customers — whom we worked really hard to get — that they are better off in the near term with another provider,” said Michael Fallquist, chief executive officer of Griddy. “We want what’s right by our consumers, so we are encouraging them to leave. We believe that transparency and that honesty will bring them back” once prices return to normal.

Texas is home to the most competitive electricity market in America. Homeowners and businesses shopping for electricity churn power providers there like credit cards. In the face of such cutthroat competition, retail power providers in the region have grown accustomed to offering new customers incredibly low rates, incentives and, at least in Griddy’s case, unusual plans that allow customers to pay wholesale power prices as opposed to fixed ones.

The ruthless nature of the business has power traders speculating over which firms might have been caught short this week in the most dramatic run-up in spot power prices they’ve ever seen, and even talk of a market bailout has surfaced.

Not all companies are asking customers to leave. Others are just pleading for them to cut back to reduce blackout risks during extreme weather.

Pulse Power, based in The Woodlands, Texas, is offering customers a chance to win a Tesla Model 3, or free electricity for up to a year if they reduce their power usage by 10% in the coming days. Austin-based Bulb is offering $2 per kilowatts-hour, up to $200, for any energy customers save.

Griddy, however, is in a different position. Its service is simple — and controversial. Members pay a $9.99 monthly fee and then pay the cost of spot power traded on Texas’s power grid based on the time of day they use it. Earlier this month, that meant customers were saving money — and at times even getting paid — to use electricity at night. But in recent days, the cost of their power has soared from about 5 to 6 cents a kilowatt-hour to $1 or more. That’s when Fallquist knew it was time to urge his customers to leave.

“I can tell you it was probably one of the hardest decisions we’ve ever made,” he said. “Nobody ever wants to see customers go.”

Griddy isn’t the only one out there actively encouraging its customers to leave. People were posting similar pleas on Twitter over the holiday weekend from other Texas utilities and retail power providers offering everything from $100 rebates to waived cancellation fees as incentives to switch.

Customers may not even be able to switch. Rizwan Nabi, president of energy consultancy Riz Energy in Houston, said several power providers in Texas have told him they aren’t accepting new customers due to this week’s volatile prices, while grid improvements are debated statewide.

Hector Torres, an energy trader in Texas, who is a Griddy customer himself, said he tried to switch services over the long weekend but couldn’t find a company willing to take him until Wednesday, when the weather is forecast to turn warmer.

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European Grid Frequency Clock Slowdown has made appliance clocks run minutes behind as AC frequency drifts on the 50 Hz electricity grid, driven by a Kosovo-Serbia billing dispute and ENTSO-E monitored supply-demand imbalance.

Key Points

An EU-wide timing error where 50 Hz AC deviations slow appliance clocks due to Kosovo-Serbia grid imbalances.

✅ Clocks drifted up to six minutes across interconnected Europe

✅ Cause: unpaid power in N. Kosovo, contested by Serbia

✅ ENTSO-E reported 50 Hz deviations from supply-demand mismatch

Over the past couple of months, Europeans have noticed time slipping away from them. It’s not just their imaginations: all across the continent, clocks built into home appliances like ovens, microwaves, and coffee makers have been running up to six minutes slow. The unlikely cause? A dispute between Kosovo and Serbia over who pays the electricity bill.

To make sense of all this, you need to know that the clocks in many household devices use the frequency of electricity to keep time. Electric power is delivered to our homes in the form of an alternating current, where the direction of the flow of electricity switches back and forth many times a second. (How this system came to be established is complex, but the advantage is that it allows electricity to be transmitted efficiently.) In Europe, this frequency is 50 Hertz — meaning a current alternating of 50 times a second. In America, it’s 60 Hz, and during peak summer demand utilities often prepare for blackouts as heat drives loads higher.

Since the 1930s, manufacturers have taken advantage of this feature to keep time. Each clock needs a metronome — something with a consistent rhythm that helps space out each second — and an alternating current provides one, saving the cost of extra components. Customers simply set the time on their oven or microwave once, and the frequency keeps it precise.

At least, that’s the theory. But because this timekeeping method is reliant on electrical frequency, when the frequency changes, so do the clocks. That is what has been happening in Europe.

The news was announced this week by ENTSO-E, the agency that oversees the single, huge electricity grid connecting 25 European countries and which recently synchronized with Ukraine to bolster regional resilience. It said that variations in the frequency of the AC caused by imbalances between supply and demand on the grid have been messing with the clocks. The imbalance is itself caused by a political argument between Serbia and Kosovo. “This is a very sensitive dispute that materializes in the energy issues,” Susanne Nies, a spokesperson for ENTSO-E, told The Verge.

Essentially, after Kosovo declared independence from Serbia in 2008, there were long negotiations over custody of utilities like telecoms and electricity infrastructure. As part of the ongoing agreements (Serbia still does not recognize Kosovo as a sovereign state), four Serb-majority districts in the north of Kosovo stopped paying for electricity. Kosovo initially covered this by charging the rest of the country more, but last December, it decided it had had enough and stopped paying. This led to an imbalance: the Kosovan districts were still using electricity, but no one was paying to put it on the grid.

This might sound weird, but it’s because electricity grids work on a system of supply and demand, where surging consumption has even triggered a Nordic grid blockade in response to constrained flows. As Stewart Larque of the UK’s National Grid explains, you want to keep the same amount of electricity going onto the grid from power stations as the amount being taken off by homes and businesses. “Think of it like driving a car up a hill at a constant speed,” Larque told The Verge. “You need to carefully balance acceleration with gravity.” (The UK itself has not been affected by these variations because it runs its own grid.)

“THEY ARE FREE-RIDING ON THE SYSTEM.”

This balancing act is hugely complex and requires constant monitoring of supply and demand and communication between electricity companies across Europe, and growing cyber risks have spurred a renewed focus on protecting the U.S. power grid among operators worldwide. The dispute between Kosovo and Serbia, though, has put this system out of whack, as the two governments have been refusing to acknowledge what the other is doing.

“The Serbians [in Kosovo] have, according to our sources, not been paying for their electricity. So they are free-riding on the system,” says Nies.

The dispute came to a temporary resolution on Tuesday, when the Kosovan government stepped up to the plate and agreed to pay a fee of €1 million for the electricity used by the Serb-majority municipalities. “It is a temporary decision but as such saves our network functionality,” said Kosovo’s prime minister Ramush Haradinaj. In the longer term, though, a new agreement will need to be reached.

There have been rumors that the increase in demand from northern Kosovo was caused by cryptocurrency miners moving into the area to take advantage of the free electricity. But according to ENTSO-E, this is not the case. “It is absolutely unrelated to cryptocurrency,” Nies told The Verge. “There’s a lot of speculation about this, and it’s absolutely unrelated.” Representatives of Serbia’s power operator, EMS, refused to answer questions on this.

For now, “Kosovo is in balance again,” says Nies. “They are producing enough [electricity] to supply the population. The next step is to take the system back to normal, which will take several weeks.” In other words, time will return to normal for Europeans — if they remember to change their clocks, even as the U.S. power grid sees more blackouts than other developed nations.

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UK Coal-Free Electricity Record highlights rapid growth in renewables as National Grid phases out coal; wind, solar, and offshore projects surge, green tariffs expand, and energy comparison helps consumers switch to cheaper, cleaner deals.

Key Points

Britain's longest coal-free run, enabled by renewables, lower demand, and grid shifts for cheaper, greener tariffs.

✅ Record set after two months without coal-fired generation

✅ Renewables outpace fossil fuels; wind and solar dominate

✅ Green tariffs expand; prices at three-year lows

On Wednesday 10 June, Britain hit a significant landmark: the UK went for two full months without burning coal to generate power – that's the longest period since the 1880s, following earlier milestones such as a full week without coal power in the recent past.

According to the National Grid, Britain has now run its electricity network without burning coal since midnight on the 9 April. This coal-free period has beaten the country’s previous record of 18 days, six hours and 10 minutes, which was set in June 2019, even though low-carbon generation stalled in 2019 according to analyses.

With such a shift in Britain’s drive for renewables and lower electricity demand following the coronavirus lockdown, as Britain recorded its cleanest electricity during lockdown to date, now may be the perfect time to do an online energy comparison and switch to a cheaper, greener deal.

Only a decade ago, around 40 per cent of Britain’s electricity came from coal generation, but since then the country has gradually shifted towards renewable energy, with the coal share at record lows in the system today. When Britain was forced into lockdown in response to the coronavirus pandemic, electricity demand dropped sharply, and the National Grid took the four remaining coal-fired plants off the network.

Over the past 10 years, Britain has invested heavily in renewable energy. Back in 2010, only 3 per cent of the country's electricity came from wind and solar, and many people remained sceptical. However, now, the UK has the biggest offshore wind industry in the world. Plus, last year, construction of the world’s single largest wind farm was completed off the coast of Yorkshire.

At the same time, Drax – Britain’s biggest power plant – has started to switch from burning coal to burning compressed wooden pellets instead, reflecting the UK's progress as it keeps breaking its coal-free energy record again across the grid. By this time next year, the plant hopes to have phased out coal entirely.

So far this year, renewables have generated more power than all fossil fuels put together, the BBC reports, and the energy dashboard shows the current mix in real time. Renewables have been responsible for 37 per cent of electricity supplied to the network, with wind and solar surpassing nuclear for the first time, while fossil fuels have accounted for 35 per cent. During the same period, nuclear accounted for 18 per cent and imports made up the remaining 10 per cent.

What does this mean for consumers?

As the country’s electricity supply moves more towards renewables, customers have more choice than ever before. Most of the ‘Big Six’ energy companies now have tariffs that offer 100 per cent green electricity. On top of this, specialist green energy suppliers such as Bulb, Octopus and Green Energy UK make it easier than ever to find a green energy tariff.

The good news is that our energy comparison research suggests that green energy doesn’t have to cost you more than a traditional fixed-price energy contract would. In fact, some of the cheapest energy suppliers are actually green companies.

At present, energy bills are at three-year lows, which means that now is the perfect time to switch supplier. As prices remain low and renewables begin to dominate the marketplace, more switchers will be drawn to green energy deals than ever before.

However, if you’re interested in choosing a green energy supplier, make sure that you look at the company's fuel mix. This way, you’ll be able to see whether they are guaranteeing the usage of green energy, or whether they’re just offsetting your usage. All suppliers must report how their energy is generated to Ofgem, so you’ll easily be able to compare providers.

You may find that you pay more for a supplier that generates its own energy from renewables, or pay less if the supplier simply matches your usage by buying green energy. You can decide which option is right for you after comparing the prices.

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