Question of utility profits is contentious

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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Advanced Traffic Light System for Geothermal Safety models fracture growth and friction with rock physics, geophones, and supercomputers to predict induced seismicity during hydraulic stimulation, enabling real-time risk control for ETH Zurich and SED.

Key Points

ATLS uses rock physics, geophones, and HPC to forecast induced seismicity in real time during geothermal stimulation.

✅ Real-time seismic risk forecasts during hydraulic stimulation

✅ Uses rock physics, friction, and fracture modeling on HPC

✅ Supports ETH Zurich and SED field tests in Iceland and Bedretto

The Swiss Earthquake Service and ETH Zurich want to make geothermal energy safer, so news piece from Switzerland earlier this month. This is to be made possible by new software, including machine learning, and the computing power of supercomputers. The first geothermal tests have already been carried out in Iceland, and more will follow in the Bedretto laboratory.

In areas with volcanic activity, the conditions for operating geothermal plants are ideal. In Iceland, the Hellisheidi power plant makes an important contribution to sustainable energy use, alongside innovations like electricity from snow in cold regions.

Deep geothermal energy still has potential. This is the basis of the 2050 energy strategy. While the inexhaustible source of energy in volcanically active areas along fault zones of the earth’s crust can be tapped with comparatively little effort and, where viable, HVDC transmission used to move power to demand centers, access on the continents is often much more difficult and risky. Because the geology of Switzerland creates conditions that are more difficult for sustainable energy production.

Improve the water permeability of the rock

On one hand, you have to drill four to five kilometers deep to reach the correspondingly heated layers of earth in Switzerland. It is only at this depth that temperatures between 160 and 180 degrees Celsius can be reached, which is necessary for an economically usable water cycle. On the other hand, the problem of low permeability arises with rock at these depths. “We need a permeability of at least 10 millidarcy, but you can typically only find a thousandth of this value at a depth of four to five kilometers,” says Thomas Driesner, professor at the Institute of Geochemistry and Petrology at ETH Zurich.

In order to improve the permeability, water is pumped into the subsurface using the so-called “fracture”. The water acts against friction, any fracture surfaces shift against each other and tensions are released. This hydraulic stimulation expands fractures in the rock so that the water can circulate in the hot crust. The fractures in the earth’s crust originate from tectonic tensions, caused in Switzerland by the Adriatic plate, which moves northwards and presses against the Eurasian plate.

In addition to geothermal energy, the “Advanced Traffic Light System” could also be used in underground construction or in construction projects for the storage of carbon dioxide.

Quake due to water injection

The disadvantage of such hydraulic stimulations are vibrations, which are often so weak or cannot be perceived without measuring instruments. But that was not the case with the geothermal projects in St. Gallen 2013 and Basel 2016. A total of around 11,000 cubic meters of water were pumped into the borehole in Basel, causing the pressure to rise. Using statistical surveys, the magnitudes 2.4 and 2.9 defined two limit values ??for the maximum permitted magnitude of the earthquakes generated. If these are reached, the water supply is stopped.

In Basel, however, there was a series of vibrations after a loud bang, with a time delay there were stronger earthquakes, which startled the residents. In both cities, earthquakes with a magnitude greater than 3 have been recorded. Since then it has been clear that reaching threshold values ??determines the stop of the water discharge, but this does not guarantee safety during the actual drilling process.

Simulation during stimulation

The Swiss Seismological Service SED and the ETH Zurich are now pursuing a new approach that can be used to predict in real time, building on advances by electricity prediction specialists in Europe, during a hydraulic stimulation whether noticeable earthquakes are expected in the further course. This is to be made possible by the so-called “Advanced Traffic Light System” based on rock physics, a software developed by the SED, which carries out the analysis on a high-performance computer.

Geophones measure the ground vibrations around the borehole, which serve as indicators for the probability of noticeable earthquakes. The supercomputer then runs through millions of possible scenarios, similar to algorithms to prevent power blackouts during ransomware attacks, based on the number and type of fractures to be expected, the friction and tensions in the rock. Finally, you can filter out the scenario that best reflects the underground.

Further tests in the mountain

However, research is currently still lacking any real test facility for the system, because incorrect measurements must be eliminated and a certain data format adhered to before the calculations on the supercomputer. The first tests were carried out in Iceland last year, with more to follow in the Bedretto geothermal laboratory in late summer, where reliable backup power from fuel cell solutions can keep instrumentation running. An optimum can now be found between increasing the permeability of rock layers and an adequate water supply.

The new approach could make geothermal energy safer and ultimately help this energy source to become more accepted, while grid upgrades like superconducting cables improve efficiency. Research also sees areas of application wherever artificially caused earthquakes can occur, such as in underground mining or in the storage of carbon dioxide underground.

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Uranium Critical Mineral Reclassification signals a US executive order directing USGS to restore critical status, boosting nuclear energy, domestic uranium mining, streamlined permitting, federal support, and energy security amid import reliance and supply chain risks.

Key Points

A policy relisting uranium as a critical mineral to unlock funding, speed permits, and strengthen U.S. nuclear security.

✅ Directs Interior to have USGS reconsider uranium classification

✅ Speeds permits for domestic uranium mining projects

✅ Targets import dependence and strengthens energy security

In a strategic move to bolster the United States' nuclear energy sector, former President Donald Trump issued an executive order on January 20, 2025, directing the Secretary of the Interior to instruct the U.S. Geological Survey (USGS) to reconsider classifying uranium as a critical mineral. This directive aims to enhance federal support and streamline permitting processes for domestic uranium projects, thereby strengthening U.S. energy security objectives.

Reclassification of Uranium as a Critical Mineral

The USGS had previously removed uranium from its critical minerals list in 2022, categorizing it as a "fuel mineral" that did not qualify for such designation. The recent executive order seeks to reverse this decision, recognizing uranium's strategic importance in the context of the nation's energy infrastructure and geopolitical considerations.

Implications for Domestic Uranium Production

Reclassifying uranium as a critical mineral is expected to unlock federal funding and expedite the permitting process for uranium mining projects within the United States. This initiative is particularly pertinent given the significant decline in domestic uranium production over the past two decades. According to the U.S. Energy Information Administration, domestic production has decreased by 96%, from 4.8 million pounds in 2014 to approximately 121,296 pounds in the third quarter of 2024.

Current Uranium Supply Dynamics

Despite the push for increased domestic production, the U.S. remains heavily reliant on uranium imports. In 2022, 27% of U.S. uranium purchases were sourced from Canada, with an additional 57% imported from countries including Kazakhstan, Uzbekistan, Australia, and Russia; a recent ban on Russian uranium could further disrupt these supply patterns and heighten risks. This reliance on foreign sources has raised concerns about energy security, especially in light of recent geopolitical tensions.

Challenges and Considerations

While the executive order represents a significant step toward revitalizing the U.S. nuclear energy sector, several challenges persist, and energy dominance faces constraints that will shape implementation:

• Regulatory Hurdles: Accelerating the permitting process for uranium mining projects involves navigating complex environmental and regulatory frameworks, though recent permitting reforms for geothermal hint at potential pathways, which can be time-consuming and contentious.

• Market Dynamics: The uranium market is subject to global supply and demand fluctuations, and domestic producers may face competition from established international suppliers.

• Infrastructure Development: Expanding domestic uranium production necessitates substantial investment in mining infrastructure and workforce development, areas that have been underfunded in recent years.

Broader Implications for Nuclear Energy Policy

The executive order aligns with a broader strategy to revitalize the U.S. nuclear energy industry, where ongoing nuclear innovation is critical to delivering stable, low-emission power. The increasing demand for nuclear energy is driven by the global push for zero-emissions energy sources and the need to support power-intensive technologies, such as artificial intelligence servers.

Former President Trump's executive order to reclassify uranium as a critical mineral, aligning with his broader energy agenda and a prior pledge to end the 'war on coal', signifies a pivotal moment for the U.S. nuclear energy sector. By potentially unlocking federal support, including programs advanced by the Nuclear Innovation Act, and streamlining permitting processes, this initiative aims to reduce dependence on foreign uranium sources and enhance national energy security. However, realizing these objectives will require addressing regulatory challenges, market dynamics, and infrastructure needs to ensure the successful revitalization of the domestic uranium industry.

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Canadian Power Crews Aid Florida after Hurricane Irma, supporting power restoration for Tampa Electric and Florida Power & Light. Hydro One and Nova Scotia Power teams provide mutual aid to speed outage repairs across communities.

Key Points

Mutual aid effort sending Canadian utility crews to restore power and repair outages in Florida after Hurricane Irma.

✅ Hydro One and Nova Scotia Power deploy line technicians

✅ Support for Tampa Electric and Florida Power & Light

✅ Goal: rapid power restoration and outage repairs statewide

Hundreds of Canadian power crews are heading to Florida to help restore power to millions of people affected by Hurricane Irma.

Two dozen Nova Scotia Power employees were en route Tampa on Tuesday morning. An additional 175 Hydro One employees from across Ontario are also heading south. Tuesday to assist after receiving a request for assistance from Tampa Electric.

Nearly 7½ million customers across five states were without power Tuesday morning as Irma — now a tropical storm — continued inland, while a power outage update from the Carolinas underscored the regional strain.

In an update On Tuesday, Florida Power & Light said its "army" of crews had already restored power to 40 per cent of the five million customers affected by Irma in the first 24 hours.

FPL said it expects to have power restored in nearly all of the eastern half of the state by the end of this coming weekend. Almost everyone should have power restored by the end of day on Sept. 22, except for areas still under water.Jason Cochrane took a flight from Halifax Stanfield International Airport along with 19 other NSP power line technicians, two supervisors and a restoration team lead, drawing on lessons from the Maritime Link first power project between Newfoundland and Nova Scotia. "It's different infrastructure than what we have to a certain extent, so there'll be a bit of a learning curve there as well," Cochrane said. "But we'll be integrated into their workforce, so we'll be assisting them to get everything put back together."

The NSP team will join 86 other Nova Scotians from their parent company, Emera, who are also heading to Tampa. Halifax-based Emera, whose regional projects include the Maritime Link, owns a subsidiary in Tampa.

"We're going to be doing anything that we can to help Tampa Electric get their customers back online," said NSP spokesperson Tiffany Chase. "We know there's been significant damage to their system as a result of that severe storm and so anything that our team can do to assist them, we want to do down in Tampa."

Crews have been told to expect to be on the ground in the U.S. for two weeks, but that could change as they get a better idea of what they're dealing with.

'It's neat to have an opportunity like this to go to another country and to help out.'- Jason Cochrane, power line technician

"It's neat to have an opportunity like this to go to another country and to help out and to get the power back on safely," said Cochrane.

Chase said she doesn't know how much the effort will cost but it will be covered by Tampa Electric. She also said Nova Scotia Power will pull its crews back if severe weather heads toward Atlantic Canada, as utilities nationwide work to adapt to climate change in their planning.

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U.S. Wind Power 2025 drives record capacity additions, with FERC data showing robust renewable energy growth, IRA incentives, onshore and offshore projects, utility-scale generation, grid integration, and manufacturing investment boosting clean electricity across key states.

Key Points

Overview of record wind additions, IRA incentives, and grid expansion defining the U.S. clean electricity mix in 2025.

✅ FERC: 30.1% of new U.S. capacity in Jan 2025 from wind

✅ Major projects: Cedar Springs IV, Boswell, Prosperity, Golden Hills

✅ IRA incentives drive onshore, offshore builds and manufacturing

In early 2025, wind power has significantly strengthened its position in the United States' electricity generation portfolio. According to data from the Federal Energy Regulatory Commission (FERC), wind energy accounted for 30.1% of the new electricity capacity added in January 2025, and as the most-used renewable source in the U.S., it also surpassed the previous record set in 2024. This growth is attributed to substantial projects such as the 390.4 MW Cedar Springs Wind IV and the 330.0 MW Boswell Wind Farm in Wyoming, along with the 300.0 MW Prosperity Wind Farm in Illinois and the 201.0 MW Golden Hills Wind Farm Expansion in Oregon. 

The expansion of wind energy capacity is part of a broader trend where solar and wind together accounted for over 98% of the new electricity generation capacity added in the U.S. in January 2025. This surge is further supported by the federal government's Inflation Reduction Act (IRA) and broader policy support for renewables, which has bolstered incentives for renewable energy projects, leading to increased investments and the establishment of new manufacturing facilities. 

By April 2025, clean electricity sources, including wind and solar, were projected to surpass 51% of total utility-scale electricity generation in the U.S., building on a 25.5% renewable share seen in recent data, marking a significant milestone in the nation's energy transition. This achievement is attributed to a combination of factors: a seasonal drop in electricity demand during the spring shoulder season, increased wind speeds in key areas like Texas, and higher solar production due to longer daylight hours and expanded capacity in states such as California, Arizona, and Nevada, supported by record installations across the solar and storage industry. 

Despite a 7% decline in wind power production in early April compared to the same period in 2024—primarily due to weaker wind speeds in regions like Texas—the overall contribution of wind energy remained robust, supported by an 82% clean-energy pipeline that includes wind, solar, and batteries. This resilience underscores the growing reliability of wind power as a cornerstone of the U.S. electricity mix. 

Looking ahead, the U.S. Department of Energy projects that wind energy capacity will continue to grow, with expectations of adding between 7.3 GW and 9.9 GW in 2024, and potentially increasing to 14.5 GW to 24.8 GW by 2028. This growth is anticipated to be driven by both onshore and offshore wind projects, with onshore wind representing the majority of new additions, continuing a trajectory since surpassing hydro capacity in 2016 in the U.S.

Early 2025 has witnessed a notable increase in wind power's share of the U.S. electricity generation mix. This trend reflects the nation's ongoing commitment to expanding renewable energy sources, especially after renewables surpassed coal in 2022, supported by favorable policies and technological advancements. As the U.S. continues to invest in and develop wind energy infrastructure, the role of wind power in achieving a cleaner and more sustainable energy future becomes increasingly pivotal.

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Africa Energy Investment must quadruple, says IEA, to deliver electricity access via grids, mini-grids, and stand-alone solar PV, wind, hydropower, natural gas, and geothermal, targeting $120 billion annually and 2.5% of GDP.

Key Points

Africa Energy Investment funds reliable, low-carbon electricity via grids, mini-grids, and renewables.

✅ Requires about $120B per year, or 2.5% of GDP

✅ Mix: grids, mini-grids, stand-alone solar PV and wind

✅ Targets reliability, economic growth, and electricity access

African countries will need to quadruple their rate of investment in their power sectors for the next two decades to bring reliable electricity to all Africans, as outlined in the IEA’s path to universal access analysis, an International Energy Agency (IEA) study published on Friday said.

If African countries continue on their policy trajectories, 530 million Africans will still lack electricity in 2030, the IEA report said. It said bringing reliable electricity to all Africans would require annual investment of around $120 billion and a global push for clean, affordable power to mobilize solutions.

“We’re talking about 2.5% of GDP that should go into the power sector,” Laura Cozzi, the IEA’s Chief Energy Modeller, told journalists ahead of the report’s launch. “India’s done it over the past 20 years. China has done it, with solar PV growth outpacing any other fuel, too. So it’s something that is doable.”

Taking advantage of technological advances and optimizing natural resources, as highlighted in a renewables roadmap, could help Africa’s economy grow four-fold by 2040 while requiring just 50% more energy, the agency said.

Africa’s population is currently growing at more than twice the global average rate. By 2040, it will be home to more than 2 billion people. Its cities are forecast to expand by 580 million people, a historically unprecedented pace of urbanization.

While that growth will lead to economic expansion, it will pile pressure on power sectors that have already failed to keep up with demand, with the sub-Saharan electricity challenge intensifying across the region. Nearly half of Africans - around 600 million people - do not have access to electricity. Last year, Africa accounted for nearly 70% of the global population lacking power, a proportion that has almost doubled since 2000, the IEA found.

Some 80% of companies in sub-Saharan Africa suffered frequent power disruptions in 2018, leading to financial losses that curbed economic growth.

The IEA recommended changing how power is distributed, with mini-grids and stand-alone systems like household solar playing a larger role in complementing traditional grids as targeted efforts to accelerate access funding gain momentum.

According to IEA Executive Director Fatih Birol, with the right government policies and energy strategies, Africa has an opportunity to pursue a less carbon-intensive development path than other regions.

“To achieve this, it has to take advantage of the huge potential that solar, wind, hydropower, natural gas and energy efficiency offer,” he said.

Despite possessing the world’s greatest solar potential, Africa boasts just 5 gigawatts of solar photovoltaics (PV), or less than 1% of global installed capacity, a slow green transition that underscores the scale of the challenge, the report stated.

To meet demand, African nations should add nearly 15 gigawatts of PV each year through 2040. Wind power should also expand rapidly, particularly in Ethiopia, Kenya, Senegal and South Africa. And Kenya should develop its geothermal resources.

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