New material makes electricity from waste heat

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.

Related News

• Electricity Forum News

• Power Generation News

25% Tariff on Canadian Imports threatens New York energy markets, disrupting hydroelectric power and natural gas supply chains, raising electricity prices, increasing gas costs, and intensifying trade tensions, policy uncertainty, and cross-border logistics risks.

Key Points

A U.S. policy imposing 25% duties on Canadian goods, risking higher New York electricity and natural gas costs.

✅ Hydroelectric and gas imports face costlier cross-border flows

✅ Higher utility bills for NY households and businesses

✅ Supply chain volatility and policy uncertainty increase

President Donald Trump announced the imposition of a 25% tariff on all imports from Canada, citing concerns over drug trafficking and illegal immigration. This decision has raised significant concerns among experts and residents in New York, who warn that the tariff could lead to increased electricity and gas prices in the state.

Impact on New York's Energy Sector

New York relies heavily on energy imports from Canada, particularly electricity and natural gas. Canada is a major supplier of hydroelectric power to the northeastern United States, including New York, with its electricity exports at risk amid trade tensions. The imposition of a 25% tariff on Canadian goods could disrupt this supply chain, leading to higher energy costs for consumers and businesses in New York. Justin Wilcox, an energy analyst, stated, "If the tariff is implemented, it could lead to increased costs for electricity and gas, affecting both consumers and businesses."

Potential Economic Consequences

The increased energy costs could have broader economic implications for New York, and some experts advise against cutting Quebec's exports to avoid exacerbating market volatility. Higher electricity and gas prices may lead to increased operational costs for businesses, potentially resulting in higher prices for goods and services, while tariff threats have boosted support for Canadian energy projects that could reshape regional supply. This could exacerbate the cost-of-living challenges faced by residents and strain the state's economy.

Political and Diplomatic Reactions

The tariff has also sparked political and diplomatic reactions, including threats to cut U.S. electricity exports from Ontario that raised tensions. New York Governor Kathy Hochul expressed concern over the potential economic impact, stating, "We are closely monitoring the situation and are prepared to take necessary actions to protect New York's economy." Additionally, Canadian officials have expressed their disapproval of the tariff, and Ontario Premier Doug Ford's Washington meeting underscored ongoing discussions, emphasizing the importance of the trade relationship between the two countries.

Historical Context

This development is part of a broader pattern of trade tensions between the United States and its neighbors. In 2018, the U.S. imposed tariffs on Canadian steel and aluminum, leading to retaliatory measures from Canada. The current situation underscores the ongoing challenges in international trade relations, where a recent tariff threat delayed Quebec's green energy bill and highlighted the potential domestic impacts of such policies.

The imposition of a 25% tariff on Canadian imports by President Trump has raised significant concerns in New York regarding potential increases in electricity and gas prices. Experts warn that this could lead to higher costs for consumers and businesses, with broader economic implications for the state. As the situation develops, it will be crucial to monitor the responses from both state and federal officials, as well as how Canadians support tariffs on energy and minerals may influence policy, and the potential for diplomatic negotiations to address these trade tensions.

Related News

• Electricity Forum News

• Energy Policy News

Space solar power promises wireless energy from orbital solar satellites via microwave or laser power beaming, using photovoltaics and rectennas. NRL and AFRL advances hint at 24-7 renewable power delivery to Earth and airborne drones.

Key Points

Space solar power beams orbital solar energy to Earth via microwaves or lasers, enabling continuous wireless electricity.

✅ Harvests sunlight in orbit and transmits via microwaves or lasers

✅ Provides 24-7 renewable power, independent of weather or night

✅ Enables wireless power for remote sites, grids, and drones

Earlier this year, a small group of spectators gathered in David Taylor Model Basin, the Navy’s cavernous indoor wave pool in Maryland, to watch something they couldn’t see. At each end of the facility there was a 13-foot pole with a small cube perched on top. A powerful infrared laser beam shot out of one of the cubes, striking an array of photovoltaic cells inside the opposite cube. To the naked eye, however, it looked like a whole lot of nothing. The only evidence that anything was happening came from a small coffee maker nearby, which was churning out “laser lattes” using only the power generated by the system as ambitions for cheap abundant electricity gain momentum worldwide.

The laser setup managed to transmit 400 watts of power—enough for several small household appliances—through hundreds of meters of air without moving any mass. The Naval Research Lab, which ran the project, hopes to use the system to send power to drones during flight. But NRL electronics engineer Paul Jaffe has his sights set on an even more ambitious problem: beaming solar power to Earth from space. For decades the idea had been reserved for The Future, but a series of technological breakthroughs and a massive new government research program suggest that faraway day may have finally arrived as interest in space-based solar broadens across industry and government.

Since the idea for space solar power first cropped up in Isaac Asimov’s science fiction in the early 1940s, scientists and engineers have floated dozens of proposals to bring the concept to life, including inflatable solar arrays and robotic self-assembly. But the basic idea is always the same: A giant satellite in orbit harvests energy from the sun and converts it to microwaves or lasers for transmission to Earth, where it is converted into electricity. The sun never sets in space, so a space solar power system could supply renewable power to anywhere on the planet, day or night, as recent tests show we can generate electricity from the night sky as well, rain or shine.

Like fusion energy, space-based solar power seemed doomed to become a technology that was always 30 years away. Technical problems kept cropping up, cost estimates remained stratospheric, and as solar cells became cheaper and more efficient, and storage improved with cheap batteries, the case for space-based solar seemed to be shrinking.

That didn’t stop government research agencies from trying. In 1975, after partnering with the Department of Energy on a series of space solar power feasibility studies, NASA beamed 30 kilowatts of power over a mile using a giant microwave dish. Beamed energy is a crucial aspect of space solar power, but this test remains the most powerful demonstration of the technology to date. “The fact that it’s been almost 45 years since NASA’s demonstration, and it remains the high-water mark, speaks for itself,” Jaffe says. “Space solar wasn’t a national imperative, and so a lot of this technology didn’t meaningfully progress.”

John Mankins, a former physicist at NASA and director of Solar Space Technologies, witnessed how government bureaucracy killed space solar power development firsthand. In the late 1990s, Mankins authored a report for NASA that concluded it was again time to take space solar power seriously and led a project to do design studies on a satellite system. Despite some promising results, the agency ended up abandoning it.

In 2005, Mankins left NASA to work as a consultant, but he couldn’t shake the idea of space solar power. He did some modest space solar power experiments himself and even got a grant from NASA’s Innovative Advanced Concepts program in 2011. The result was SPS-ALPHA, which Mankins called “the first practical solar power satellite.” The idea, says Mankins, was “to build a large solar-powered satellite out of thousands of small pieces.” His modular design brought the cost of hardware down significantly, at least in principle.

Jaffe, who was just starting to work on hardware for space solar power at the Naval Research Lab, got excited about Mankins’ concept. At the time he was developing a “sandwich module” consisting of a small solar panel on one side and a microwave transmitter on the other. His electronic sandwich demonstrated all the elements of an actual space solar power system and, perhaps most important, it was modular. It could work beautifully with something like Mankins' concept, he figured. All they were missing was the financial support to bring the idea from the laboratory into space.

Jaffe invited Mankins to join a small team of researchers entering a Defense Department competition, in which they were planning to pitch a space solar power concept based on SPS-ALPHA. In 2016, the team presented the idea to top Defense officials and ended up winning four out of the seven award categories. Both Jaffe and Mankins described it as a crucial moment for reviving the US government’s interest in space solar power.

They might be right. In October, the Air Force Research Lab announced a $100 million program to develop hardware for a solar power satellite. It’s an important first step toward the first demonstration of space solar power in orbit, and Mankins says it could help solve what he sees as space solar power’s biggest problem: public perception. The technology has always seemed like a pie-in-the-sky idea, and the cost of setting up a solar array on Earth is plummeting, as proposals like a tenfold U.S. solar expansion signal rapid growth; but space solar power has unique benefits, chief among them the availability of solar energy around the clock regardless of the weather or time of day.

It can also provide renewable energy to remote locations, such as forward operating bases for the military, which has deployed its first floating solar array to bolster resilience. And at a time when wildfires have forced the utility PG&E to kill power for thousands of California residents on multiple occasions, having a way to provide renewable energy through the clouds and smoke doesn’t seem like such a bad idea. (Ironically enough, PG&E entered a first-of-its-kind agreement to buy space solar power from a company called Solaren back in 2009; the system was supposed to start operating in 2016 but never came to fruition.)

“If space solar power does work, it is hard to overstate what the geopolitical implications would be,” Jaffe says. “With GPS, we sort of take it for granted that no matter where we are on this planet, we can get precise navigation information. If the same thing could be done for energy, especially as peer-to-peer energy sharing matures, it would be revolutionary.”

Indeed, there seems to be an emerging race to become the first to harness this technology. Earlier this year China announced its intention to become the first country to build a solar power station in space, and for more than a decade Japan has considered the development of a space solar power station to be a national priority. Now that the US military has joined in with a $100 million hardware development program, it may only be a matter of time before there’s a solar farm in the solar system.

Related News

• Electricity Forum News

• Renewable Energy News

Little Haiti Garbage Truck Power Outage in Miami after mechanical arms snagged power lines, snapping power poles; FPL crews, police, and businesses faced traffic delays, safety risks, and rapid restoration efforts across the neighborhood.

Key Points

A Miami incident where a garbage truck snagged power lines, toppling poles and causing outages and traffic delays.

✅ Mechanical arms caught overhead lines; three power poles snapped

✅ FPL dispatched, police directed traffic; restoration prioritized

✅ Dozens of businesses affected; afternoon rush hour congestion

On January 16, 2025, a significant incident unfolded in Miami's Little Haiti neighborhood when a garbage truck collided with power lines, causing three power poles to collapse and resulting in widespread power outages and traffic disruptions.

Incident Details

Around 1:30 p.m., a garbage truck traveling west on Northeast 82nd Street toward Interstate 95 became entangled with overhead power lines. The truck's mechanical arms caught the lines, leading to the snapping of three power poles and plunging the area into darkness, a scenario echoed by urban incidents like a manhole fire that left thousands without power. Witnesses reported a loud boom followed by an immediate power outage. One local business owner described the event, stating, "There was a loud boom, and suddenly the power went out."

Impact on the Community

The incident caused significant disruptions in the Little Haiti area. At least a dozen businesses were affected by the power outage, and in wider Florida events restoration can take weeks depending on damage, leading to operational halts and potential financial losses. The timing of the crash, during the afternoon rush hour, exacerbated traffic congestion as commuters were forced to navigate through the area, and similar disruptions occur when strong winds knock out power, further complicating the situation.

Response and Recovery Efforts

In response to the incident, Miami police directed traffic to alleviate congestion and ensure public safety. Florida Power & Light (FPL) crews, known for their major outage response, were promptly dispatched to the scene to assess the damage and begin restoration efforts. The priority was to safely remove the damaged power poles and restore electricity to the affected area. FPL's swift action was crucial in minimizing the duration of the power outage and restoring normalcy to the community.

Safety Considerations

This incident underscores the importance of safety protocols for vehicles operating in areas with overhead power lines. Garbage trucks, due to their design and operational mechanisms, are particularly susceptible to such accidents, and in broader disasters some regions require a power grid rebuild to recover, highlighting the stakes. It is imperative for operators to be vigilant and adhere to safety guidelines to prevent similar occurrences.

Community Resilience

Despite the challenges posed by the incident, the Little Haiti community demonstrated resilience. Local businesses and residents cooperated with authorities, while utilities elsewhere have restored power to thousands after major events, and the prompt response from emergency services highlighted the community's strength in the face of adversity.

Related News

• Electricity Forum News

• Utility Operations News

Energy Transition Grid Reforms address transmission capacity, interconnection, congestion management, and flexibility markets, enabling renewable integration and grid stability while optimizing network charges and access in Australia, Ireland, and Great Britain.

Key Points

Measures to expand transmission, boost flexibility, and manage congestion for reliable, low-carbon electricity systems.

✅ Transmission upgrades and interconnectors ease congestion

✅ Flexible markets, DER, and storage bolster grid stability

✅ Evolving network charges and access incentivize siting

Electricity networks globally are experiencing significant increases in the volume of renewable capacity as countries seek to decarbonise their power sectors, even as clean energy's 'dirty secret' highlights integration trade-offs, without impacting the security of supply. The scale of this change is creating new challenges for power networks and those responsible for keeping the lights on.

The latest insight paper from Cornwall Insight – Market design amidst global energy transition – looks into this issue. It examines the outlook for transmission networks, and how legacy design and policies are supporting decarbonisation, aligning with IRENA findings on renewables and shaping the system. The paper focuses on three key markets; Australia, Ireland and Great Britain (GB).

Australia's main priority is to enhance transmission capacity and network efficiency; as concerns over excess solar risking blackouts grow in distribution networks, without this, the transmission system will be a barrier to growth for decentralised flexibility and renewables. In contrast, GB and Ireland benefit from interconnection with other national markets. This provides them with additional levers that can be pulled to manage system security and supply. However, they are still trying to hone and optimise network flexibility in light of steepening decarbonisation objectives.

Unsurprisingly, renewable energy resources have been growing in all three markets, with Ireland regarded as a leader in grid integration, with this expected to continue for the foreseeable future. Many of these projects are often located in places where network infrastructure is not as well developed, creating pressure on system operation as a result.

In all three markets, unit charges are rising, driven by a reduced charging base as decentralised energy grows quickly. This combination of changes is leading to network congestion, a challenge mirrored by the US grid overhaul for renewables underway, as transmission network development struggles to keep up, and flexibility markets are being optimised and changed.

In summary, reforms are on-going in each jurisdiction to accommodate the rapid physical transformation of the generation mix. Each has its objectives and tensions which are reflective of wider global reform programmes being undertaken in most developed, liberalised and decarbonising energy markets.

Gareth Miller, CEO of Cornwall Insight, said: “Despite differences in market design and characteristics, all three markets are grappling with similar issues, that comes from committing to deep decarbonisation. This includes the most appropriate methods for charging for networks, managing access to them and dealing with issues such as network congestion and constraint.

“In all three countries, renewable projects are often placed in isolated locations, as seen in Scotland where more pylons are needed to keep the lights on, away from the traditional infrastructure that is closer to demand. However, as renewable growth is set to continue, the networks will need to transition from being demand-centric to more supply orientated.

“Both system operators and stakeholders will need to continually evaluate their market structures and designs to alleviate issues surrounding locational congestion and grid stability. Each market is at very different stages in the process in trying to improve any problems implementing solutions to allow for higher efficiencies in renewable energy integration.

“It is uncertain whether any of the proposed changes will fundamentally resolve the issues that come with increased renewables on the system. However, despite marked differences, they certainly could all learn from each other and elements of their network arrangements, as well as from US decarbonisation strategies research.”

Related News

• Electricity Forum News

• Renewable Energy News

Ukraine nuclear safety risks escalate as IAEA warns of power grid attacks threatening reactor cooling, diesel generators, and Zaporizhzhia oversight, prompting UN calls for demilitarized zones to prevent radioactive releases and accidents.

Key Points

Escalating threats from grid attacks and outages that jeopardize reactor cooling, IAEA oversight, and public safety.

✅ Power grid strikes threaten reactor cooling systems.

✅ Emergency diesel generators are last defense lines.

✅ Calls grow for demilitarized zones around plants.

In early February 2025, Rafael Grossi, Director General of the International Atomic Energy Agency (IAEA), expressed grave concerns regarding the safety of Ukraine's nuclear facilities amid ongoing Russian attacks on the country's power grids, as Kyiv warned of a difficult winter without power after deadly strikes on energy infrastructure. Grossi's warnings highlight the escalating risks to nuclear safety and the potential for catastrophic accidents.

The Threat to Nuclear Safety

Ukraine's nuclear infrastructure, including the Zaporizhzhia Nuclear Power Plant—the largest in Europe—relies heavily on a stable power supply to maintain critical cooling systems and other safety measures. Russian military operations targeting Ukraine's energy infrastructure have led to power outages, and created hazards akin to those highlighted in downed power line safety guidance during emergency repairs, jeopardizing the safe operation of these facilities. Grossi emphasized that such disruptions could result in severe nuclear accidents if cooling systems fail.

IAEA's Response and Actions

In response to these threats, the IAEA has been actively involved in monitoring and assessing the situation. Grossi visited Kyiv to inspect electrical substations and discuss safety measures with Ukrainian officials. He underscored the necessity of ensuring uninterrupted power to nuclear plants and the critical role of emergency diesel generators as a last line of defense, and noted that maintaining staffing continuity, including measures such as staff living on site at critical facilities, may be necessary. The IAEA has also postponed the rotation of its mission at the Zaporizhzhia plant due to security concerns, as reported by Reuters.

International Concerns and Diplomatic Efforts

The international community has expressed deep concern over the potential for nuclear accidents in Ukraine, echoing earlier grid overseer warnings about systemic risks in other crises that stress energy systems. The United Nations and various countries have called for the establishment of a demilitarized zone around nuclear facilities to prevent military activities that could compromise their safety. Diplomatic efforts are ongoing to facilitate dialogue between Russia and Ukraine, aiming to ensure the protection of nuclear sites and the safety of surrounding populations.

The Zaporizhzhia Nuclear Power Plant

The Zaporizhzhia Nuclear Power Plant, located in southeastern Ukraine, has been under Russian control since early in the conflict, with Rosatom cooperation agreements reflecting broader nuclear policy priorities that frame Moscow's approach to the sector. The plant consists of six reactors and has been a focal point of international concern due to its size and the potential consequences of any incident. The IAEA has been working to maintain oversight and ensure the plant's safety amid the ongoing conflict.

Potential Consequences of Nuclear Accidents

A nuclear accident at any of Ukraine's nuclear facilities could have catastrophic consequences, including the release of radioactive materials, displacement of populations, and long-term environmental damage, with communities potentially facing weeks without electricity and basic services in the aftermath. The proximity of these plants to densely populated areas further amplifies the risks. The international community continues to monitor the situation closely, emphasizing the need for immediate action to safeguard nuclear facilities.

The ongoing conflict in Ukraine has introduced unprecedented challenges to nuclear safety. The IAEA's warnings and actions underscore the critical need for international cooperation to protect nuclear facilities from the dangers posed by military activities. Ensuring the safety of these sites is paramount to prevent potential disasters that could have far-reaching humanitarian and environmental impacts, and sustained attention to nuclear workers' safety concerns helps maintain operational readiness under strain.

Related News

• Electricity Forum News

• Power Generation News