Cameco closer to UF6 plant restart

Nighttime Thermoelectric Generator converts radiative cooling into renewable energy, leveraging outer space cold; a Stanford-UCLA prototype complements solar, serving off-grid loads with low-power output during peak evening demand, using simple materials on a rooftop.

Key Points

A device converting nighttime radiative cooling into electricity, complementing solar for low-power evening needs.

✅ Uses thermocouples to convert temperature gradients to voltage.

✅ Exploits radiative cooling to outer space for night power.

✅ Complements solar; low-cost parts suit off-grid applications.

Two years ago, one freezing December night on a California rooftop, a tiny light shone weakly with a little help from the freezing night air. It wasn't a very bright glow. But it was enough to demonstrate the possibility of generating renewable power after the Sun goes down.

Working with Stanford University engineers Wei Li and Shanhui Fan, University of California Los Angeles materials scientist Aaswath Raman put together a device that produces a voltage by channelling the day's residual warmth into cooling air, effectively generating electricity from thin air with passive heat exchange.

"Our work highlights the many remaining opportunities for energy by taking advantage of the cold of outer space as a renewable energy resource," says Raman.

"We think this forms the basis of a complementary technology to solar. While the power output will always be substantially lower, it can operate at hours when solar cells cannot."

For all the merits of solar energy, it's just not a 24-7 source of power, although research into nighttime solar cells suggests new possibilities for after-dark generation. Sure, we can store it in a giant battery or use it to pump water up into a reservoir for later, but until we have more economical solutions, nighttime is going to be a quiet time for renewable solar power. 

Most of us return home from work as the Sun is setting, and that's when energy demands spike to meet our needs for heating, cooking, entertaining, and lighting.

Unfortunately, we often turn to fossil fuels to make up the shortfall. For those living off the grid, it could require limiting options and going without a few luxuries.

Shanhui Fan understands the need for a night time renewable power source well. He's worked on a number of similar devices, including carbon nanotube generators that scavenge ambient energy, and a recent piece of technology that flipped photovoltaics on its head by squeezing electricity from the glow of heat radiating out of the planet's Sun-warmed surface.

While that clever item relied on the optical qualities of a warm object, this alternative device makes use of the good old thermoelectric effect, similar to thin-film waste-heat harvesting approaches now explored.

Using a material called a thermocouple, engineers can convert a change in temperature into a difference in voltage, effectively turning thermal energy into electricity with a measurable voltage. This demands something relatively toasty on one side and a place for that heat energy to escape to on the other.

The theory is the easy part – the real challenge is in arranging the right thermoelectric materials in such a way that they'll generate a voltage from our cooling surrounds that makes it worthwhile.

To keep costs down, the team used simple, off-the-shelf items that pretty much any of us could easily get our hands on.

They put together a cheap thermoelectric generator and linked it with a black aluminium disk to shed heat in the night air as it faced the sky. The generator was placed inside a polystyrene enclosure sealed with a window transparent to infrared light, and linked to a single tiny LED.

For six hours one evening, the box was left to cool on a roof-top in Stanford as the temperature fell just below freezing. As the heat flowed from the ground into the sky, the small generator produced just enough current to make the light flicker to life.

At its best, the device generated around 0.8 milliwatts of power, corresponding to 25 milliwatts of power per square metre.

That might just be enough to keep a hearing aid working. String several together and you might just be able to keep your cat amused with a simple laser pointer. So we're not talking massive amounts of power.

But as far as prototypes go, it's a fantastic starting point. The team suggests that with the right tweaks and the right conditions, 500 milliwatts per square metre isn't out of the question.

"Beyond lighting, we believe this could be a broadly enabling approach to power generation suitable for remote locations, and anywhere where power generation at night is needed," says Raman.

While we search for big, bright ideas to drive the revolution for renewables, it's important to make sure we don't let the smaller, simpler solutions like these slip away quietly into the night.

This research was published in Joule.

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V.C. Summer nuclear plant leak update: Dominion Energy repaired a valve in the reactor cooling system; radioactive water stayed within containment, NRC oversight continues as power output ramps toward full operation.

Key Points

A minor valve leak in the reactor cooling system contained onsite; Dominion repaired it as the plant resumes power.

✅ Valve leak in piping to steam generators, not environmental release.

✅ Radioactive water remained in containment, monitored per NRC rules.

✅ Plant ramping from 17% power; full operations may take days.

The V.C. Summer nuclear power plant, which has been shut down since early November because of a pipe leak, is expected to begin producing energy in a few days, a milestone comparable to a new U.S. reactor startup reported recently.

Dominion Energy says it has fixed the small leak in a pipe valve that allowed radioactive water to drip out. The company declined to say when the plant would be fully operational, but spokesman Ken Holt said that can take several days, amid broader discussions about the stakes of early nuclear closures across the industry.

The plant was at 17 percent power Wednesday, he said, as several global nuclear project milestones continue to be reported this year.

Holt, who said Dominion is still investigating the cause, said water that leaked was part of the reactor cooling system. While the water came in contact with nuclear fuel in the reactor, the water never escaped the plant's containment building and into the environment, Holt said.

He characterized the valve leak as '"uncommon" but not unexpected. The nuclear leak occurred in piping that links the nuclear reactor with the power plant's steam generators. Hundreds of pipes are in that part of the nuclear plant, a complexity often cited in the energy debate over struggling nuclear plants nationwide.

"There is always some level of leakage when you are operating, but it is contained and monitored, and when it rises to a certain level, you may take action to stop it," Holt said.

A nuclear safety watchdog has criticized Dominion for not issuing a public notice about the leak, but both the company and the U.S. Nuclear Regulatory Commission say the amount was so small it did not require notice.

The V.C. Summer Nuclear plant is about 25 miles northwest of Columbia in Fairfield County. It was licensed in the early 1980s. At one point, Dominion's predecessor, SCE&G, partnered with state owned Santee Cooper to build two more reactors there, even as new reactors in Georgia were taking shape. But the companies walked away from the project in 2017, citing high costs and troubles with its chief contractor, Westinghouse, even as closures such as Three Mile Island's shutdown continued to influence policy.

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U.S. Energy Transition Delays stem from grid bottlenecks, permitting red tape, solar tariff uncertainty, supply-chain shocks, and scarce affordable EVs, risking deeper fossil fuel lock-in despite climate targets for renewables, transmission expansion, and decarbonization.

Key Points

Delays driven by grid limits, permitting, and supply shocks that slow renewables, transmission, EVs, and decarbonization.

✅ Grid interconnection and transmission backlogs stall renewables

✅ Tariff probes and supply chains disrupt utility-scale solar

✅ Permitting, policy gaps, and EV costs sustain fossil fuel use

Big solar projects are facing major delays. Plans to adapt the grid to clean energy are confronting mountains of red tape. Affordable electric vehicles are in short supply.

The United States is struggling to squeeze opportunity out of an energy crisis that should have been a catalyst for cleaner, domestically produced power. After decades of putting the climate on the back burner, the country is finding itself unprepared to seize the moment and at risk of emerging from the crisis even more reliant on fossil fuels.

10 steps you can take to lower your carbon footprint
The problem is not entirely unique to the United States. Across the globe, climate leaders are warning that energy shortages including coal and nuclear disruptions prompted by Russia’s unprovoked invasion of Ukraine and high gas prices driven by inflation threaten to make the energy transition an afterthought — potentially thwarting efforts to keep global temperature rise under 1.5 degrees Celsius.

“The energy crisis exacerbated by the war in Ukraine has seen a perilous doubling down on fossil fuels by the major economies,” U.N. Secretary General António Guterres said at a conference in Vienna on Tuesday, according to prepared remarks. He warned governments and investors that a failure to immediately and more aggressively embrace clean energy could be disastrous for the planet.

U.S. climate envoy John F. Kerry suggested that nations are falling prey to a flawed logic that fossil fuels will help them weather this period of instability, undermining U.S. national security and climate goals, which has seen gas prices climb to a record-high national average of $5 per gallon. “You have this new revisionism suggesting that we have to be pumping oil like crazy, and we have to be moving into long-term [fossil fuel] infrastructure building,” he said at the Time100 Summit in New York this month. “We have to push back.”

Climate envoy John F. Kerry attends the Summit of the Americas in Los Angeles on June 8. Kerry has criticized the tendency to turn toward fossil fuels in times of uncertainty. (Apu Gomes/AFP/Getty Images)
In the United States — the world’s second-largest emitter of greenhouse gases after China — the hurdles go beyond the supply-chain crisis and sanctions linked to the war in Ukraine. The country’s lofty goals for all carbon pollution to be gone from the electricity sector by 2035 and for half the cars sold to be electric by 2030 are jeopardized by years of neglect of the electrical grid, regulatory hurdles that have set projects back years, and failures by Congress and policymakers to plan ahead.
The challenges are further compounded by plans to build costly new infrastructure for drilling and exporting natural gas that will make it even harder to transition away from the fossil fuel.

“We are running into structural challenges preventing consumers and businesses from going cleaner, even at this time of high oil and gas prices,” said Paul Bledsoe, a climate adviser in the Clinton administration who now works on strategy at the Progressive Policy Institute, a center-left think tank. “It is a little alarming that even now, Congress is barely talking about clean energy.”

Consumers are eager for more wind and solar. Companies looking to go carbon-neutral are facing growing waitlists for access to green energy, and a Pew Research Center poll in late January found that two-thirds of Americans want the United States to prioritize alternative energy over fossil fuel production.

But lawmakers have balked for more than a decade at making most of the fundamental economic and policy changes such as a clean electricity standard that experts widely agree are crucial to an orderly and accelerated energy transition. The United States does not have a tax on carbon, nor a national cap-and-trade program that would reorient markets toward lowering emissions. The unraveling in Congress of President Biden’s $1.75 trillion Build Back Better plan has added to the head winds that green-energy developers face, even as climate law results remain mixed.

Vice President Harris tours electric school buses at Meridian High School in Falls Church, Va., on May 20. (Mandel Ngan/AFP/Getty Images)
“There is literally nothing pushing this forward in the U.S. beyond the tax code and some state laws,” said Heather Zichal, a former White House climate adviser who is now the chief executive of the American Clean Power Association.

The effects of the U.S. government’s halting approach are being felt by solar-panel installers, who saw the number of projects in the most recent quarter fall to the lowest level since the pandemic began. There was 24 percent less solar installed in the first quarter of 2022 than in the same quarter of 2021.

The holdup largely stems from a Commerce Department investigation into alleged tariff-dodging by Chinese manufacturers. Faced with the potential for steep retroactive penalties, hundreds of industrial-scale solar projects were frozen in early April. Weak federal policies to encourage investment in solar manufacturing left American companies ill-equipped to fill the void.

“We shut down multiple projects and had to lay off dozens of people,” said George Hershman, chief executive of SOLV Energy, which specializes in large solar installations. SOLV, like dozens of other solar companies, is now scrambling to reassemble those projects after the administration announced a pause of the tariffs.

Meanwhile, adding clean electricity to the aging power grid has become an increasingly complicated undertaking, given the failure to plan for adequate transmission lines and long delays connecting viable wind and solar projects to the electricity network.

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Canada Tariffs on U.S. Energy and Minerals signal retaliatory tariffs amid trade tensions, targeting energy exports and critical minerals, reflecting sovereignty concerns and shifting consumer behavior, reduced U.S. purchases, and demand for Canadian-made goods.

Key Points

They are proposed retaliatory tariffs on energy exports and critical minerals to counter U.S. trade pressures.

✅ 75% support tariffs; 70% back dollar-for-dollar retaliation

✅ Consumer shift: fewer U.S. purchases, more Canadian-made goods

✅ Concerns over sovereignty and U.S. trade tactics intensify

A recent survey has revealed that a significant majority of Canadians—approximately 75%—support the implementation of tariffs on energy exports and critical minerals in response to electricity exports at risk amid trade tensions with the United States. This finding underscores the nation's readiness to adopt assertive measures to protect its economic interests amid escalating trade disputes.​

Background on Trade Tensions

The trade relationship between Canada and the United States has experienced fluctuations in recent years, with both nations navigating complex issues related to tariffs and energy tariffs and trade tensions as well as trade agreements and economic policies. The introduction of tariffs has been a contentious strategy, often leading to reciprocal measures and impacting various sectors of the economy.​

Public Sentiment Towards Retaliatory Tariffs

The survey, conducted by Leger between February 14 and 17, 2025, sampled 1,500 Canadians and found that 70% favored implementing dollar-for-dollar retaliatory tariffs against the U.S. Notably, 45% of respondents were strongly in favor, while 25% were somewhat in favor. This strong support reflects widespread dissatisfaction with U.S. trade policies and growing support for Canadian energy projects among voters, alongside a collective sentiment favoring decisive action. ​

Concerns Over U.S. Economic Strategies

The survey also highlighted that 81% of Canadians are apprehensive about potential U.S. economic tactics aimed at drawing Canada into a closer political union. These concerns are fueled by statements from U.S. President Donald Trump, who has suggested annexation and employed tariffs that could spike NY energy prices to influence Canadian sovereignty. Such sentiments have heightened fears about the erosion of Canada's political autonomy under economic duress. ​

Impact on Consumer Behavior

In response to these trade tensions, including reports that Ford threatened to cut U.S. electricity exports, many Canadians have adjusted their purchasing habits. The survey indicated that 63% of respondents are buying fewer American products in stores, and 62% are reducing online purchases from U.S. retailers. Specific declines include a 52% reduction in Amazon purchases, a 50% drop in fast-food consumption from American chains, and a 43% decrease in spending at U.S.-based retail stores. Additionally, 30% of Canadians have canceled planned trips to the United States, while 68% have increased their purchases of Canadian-made products. These shifts demonstrate a tangible impact on consumer behavior driven by nationalistic sentiments and support for retaliatory measures. ​

Economic and Political Implications

The widespread support for retaliatory tariffs and the corresponding changes in consumer behavior have significant economic and political implications. Economically, while tariffs can serve as a tool for asserting national interests, they also risk triggering trade wars that can harm various sectors, including agriculture, manufacturing, and technology, with experts cautioning against cutting Quebec's energy exports in response. Politically, the situation presents a challenge for Canadian leadership to balance assertiveness in defending national interests with the necessity of maintaining a stable and mutually beneficial relationship with the U.S., Canada's largest trading partner.​

As Canada approaches its federal elections, trade policy is emerging as a pivotal issue. Voters are keenly interested in how political parties propose to navigate the complexities of international trade, particularly with the United States and how a potential U.S. administration's stance, such as Biden's approach to the energy sector could shape outcomes. The electorate's strong stance on retaliatory tariffs may influence party platforms and campaign strategies, emphasizing the need for clear and effective policies that address both the immediate concerns of trade disputes and the long-term goal of sustaining positive international relations.​

The survey results reflect a nation deeply engaged with its trade dynamics and protective of its sovereignty. While support for retaliatory tariffs is robust, it is essential for policymakers to carefully consider the broader consequences of such actions. Striking a balance between defending national interests and fostering constructive international relationships will be crucial as Canada navigates these complex trade challenges in the coming years.

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Ukraine Electricity Exports resume as the EU grid links stabilize; ENTSO-E caps, megawatt capacity, renewables, and infrastructure repairs enable power flows to Moldova, Poland, Slovakia, and Romania despite ongoing Russian strikes.

Key Points

Resumed cross-border power sales showing grid stability under ENTSO-E limits and surplus generation.

✅ Exports restart to Moldova; Poland, Slovakia, Romania next.

✅ ENTSO-E cap limits to 400 MW; more capacity under negotiation.

✅ Revenues fund grid repairs after Russian strikes.

Ukraine began resuming electricity exports to European countries on Tuesday, its energy minister said, a dramatic turnaround from six months ago when fierce Russian bombardment of power stations plunged much of the country into darkness in a bid to demoralize the population.

The announcement by Energy Minister Herman Halushchenko that Ukraine was not only meeting domestic consumption demands but also ready to restart exports to its neighbors was a clear message that Moscow’s attempt to weaken Ukraine by targeting its infrastructure did not work.

Ukraine’s domestic energy demand is “100%” supplied, he told The Associated Press in an interview, and it has reserves to export due to the “titanic work” of its engineers and international partners.

Russia ramped up infrastructure attacks in September, when waves of missiles and exploding drones destroyed about half of Ukraine's energy system, even as it built lines to reactivate the Zaporizhzhia plant in occupied territory. Power cuts were common across the country as temperatures dropped below freezing and tens of millions struggled to keep warm.

Moscow said the strikes were aimed at weakening Ukraine’s ability to defend itself, and both sides have floated a possible agreement on power plant attacks amid mounting civilian harm, while Western officials said the blackouts that caused civilians to suffer amounted to war crimes. Ukrainians said the timing was designed to destroy their morale as the war marked its first anniversary.

Ukraine had to stop exporting electricity in October to meet domestic needs.

Engineers worked around the clock, often risking their lives to come into work at power plants and keep the electricity flowing. Kyiv’s allies also provided help. In December, U.S. Secretary of State Antony Blinken announced $53 million in bilateral aid to help the country acquire electricity grid equipment, on top of $55 million for energy sector support.

Much more work remains to be done, Halushchenko said. Ukraine needs funding to repair damaged generation and transmission lines, and revenue from electricity exports would be one way to do that.

The first country to receive Ukraine’s energy exports will be Moldova, he said.

Besides the heroic work by engineers and Western aid, warmer temperatures are enabling the resumption of exports by making domestic demand lower, and across Europe initiatives like virtual power plants for homes are helping balance grids. Nationwide consumption was already down at least 30% due to the war, Halushchenko said, with many industries having to operate with less power.

Renewables like solar and wind power also come into play as temperatures rise, taking some pressure off nuclear and coal-fired power plants.

But it’s unclear if Ukraine can keep up exports amid the constant threat of Russian bombardment.

“Unfortunately now a lot of things depend on the war,” Halushchenko said. “I would say we feel quite confident now until the next winter.”

Exports to Poland, Slovakia and Romania are also on schedule to resume, he said.

“Today we are starting with Moldova, and we are talking about Poland, we are talking about Slovakia and Romania,” Halushchenko added, noting that how much will depend on their needs.

“For Poland, we have only one line that allows us to export 200 megawatts, but I think this month we will finish another line which will increase this to an additional 400 MW, so these figures could change,” he said.

Export revenue will depend on fluctuating electricity prices in Europe, where stunted hydro and nuclear output may hobble recovery efforts. In 2022, while Ukraine was still able to export energy, Ukrainian companies averaged 40 million to 70 million euros a month depending on prices, Halushchenko said.

“Even if it’s 20 (million euros) it’s still good money. We need financial resources now to restore generation and transmission lines,” he said.

Ukraine has the ability to export more than the 400 megawatt capacity limit imposed by the European Network of Transmission System Operators for Electricity, or ENTSO-E, and rising EU wind and solar output is reshaping cross-border flows. “We are in negotiations to increase this cap because today we can export even more, we have the necessary reserves in the system,” the minister said.

The current capacity limit is in line with what Ukraine was exporting in September 2022 before Ukraine diverted resources to meet domestic needs amid the Russian onslaught.

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ComEd Smart Grid Reliability drives outage reduction across Illinois, leveraging smart switches, grid modernization, and peak demand programs to keep customers powered, improve power quality, and enhance energy savings during extreme weather and severe storms.

Key Points

ComEd's smart grid performance, cutting outages and improving power quality to enhance reliability and customer savings.

✅ Smart switches reroute power to avoid customer interruptions

✅ Fewer outages during extreme weather across northern Illinois

✅ Peak Time Savings rewards for reduced peak demand usage

While the summer of 2019 set records for heat and brought severe storms, ComEd customers stayed cool thanks to record-setting reliability during the season. These smart grid investments over the last seven years helped to set records in key reliability measurements, including frequency of outages metrics, and through smart switches that reroute power around potential problem areas, avoided more than 538,000 customer interruptions from June to August.

"In a summer where we were challenged by extreme weather, we saw our smart grid investments and our people continue to deliver the highest levels of reliability, backed by extensive disaster planning across utilities, for the families and businesses we serve," said Joe Dominguez, CEO of ComEd. "We're proud to deliver the most affordable, cleanest and, as we demonstrated this summer, most reliable energy to our customers. I want to thank our 6,000 employees who work around the clock in often challenging conditions to power our communities."

ComEd has avoided more than 13 million customer interruptions since 2012, due in part to smart grid and system improvements. The avoided outages have resulted in $2.4 billion in estimated savings to society. In addition to keeping energy flowing for residents, strong power reliability continues to help persuade industrial and commercial companies to expand in northern Illinois and Chicago. The GridWise Alliance recently recognized Illinois as the No. 2 state in the nation for its smart grid implementation.

"Our smart grid investments has vastly improved the infrastructure of our system," said Terry Donnelly, ComEd president and chief operating officer. "We review the system and our operations continually to make sure we're investing in areas that benefit the greatest number of customers, and to prepare for public-health emergencies as well. On a daily basis and during storms or to reduce wildfire risk when necessary, our customers are seeing fewer and fewer interruptions to their lives and businesses."

ComEd customers also set records for energy savings this summer. Through its Peak Time Savings program and other energy-efficiency programs offered by utilities, ComEd empowered nearly 300,000 families and individuals to lower their bills by a total of more than $4 million this summer for voluntarily reducing their energy use during times of peak demand. Since the Peak Time Savings program launched in 2015, participating customers have earned a total of more than $10 million in bill credits.

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