'Rewards for Recycling' to divert 90 truckloads of material from landfill

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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Gaza Electricity Crisis drives severe power cuts in the Gaza Strip, as Hamas-PA tensions and Mahmoud Abbas's supply reductions under blockade spur fuel shortages, hospital strain, and soaring demand for batteries, LED lights, and generators.

Key Points

A prolonged Gaza power shortage from politics, blockade, and fuel cuts, disrupting daily life, hospitals, and water.

✅ Demand surges for batteries, LED lights, and generators

✅ PA cuts to Israel-supplied power deepen shortages

✅ Hospitals, water, and sanitation face critical strain

In Imad Shlayl’s electronics shop in Gaza City, the customers crowding his store are interested in only two products: LED lights and the batteries to power them.

In the already impoverished Gaza Strip, residents have learned to adapt to the fact that electricity is only available for between two and four hours a day.

But fresh anger was sparked when availability was cut further last month, at the request of the Palestinian president, Mahmoud Abbas, in an escalation of his conflict with Hamas, the Islamist group.

The shortages have defined how people live their lives, echoing Europe’s energy crisis in other regions: getting up in the middle of the night, if there is power, to run washing machines or turn on water pumps.

Only the wealthy few have frequent, long-lasting access to electricity, even as U.S. brownout risks highlight grid fragility, to power lights and fans and fridges, televisions and wifi routers, in Gaza’s stifling summer heat.

“We used to sell all sorts of things,” says Shlayl. “But it’s different these days. All we sell is batteries and chargers. Because the crisis is so deep we are selling 100 batteries a day when normally we would sell 20.”

Gaza requires 430 megawatts of power to meet daily demand, but receives only half that. Sixty megawatts are supplied by its solitary power station, now short on fuel, while the rest is provided through the Israel’s power sector and funded by Abbas’s West Bank-based Palestinian Authority (PA).

Abbas’s move to cut supplies to Gaza, which is already under a joint Israeli and Egyptian blockade – now in its 11th year – has quickly made him a hate figure among many Gazans, who question why he is punishing 2 million fellow Palestinians in what appears to be an attempt to force Hamas to relinquish control of the territory.

Though business is good for Shlayl, he is angry at the fresh shortages faced by Gazans which, as pandemic power shut-offs elsewhere have shown, affect all areas of life, from hospital emergency wards to clean water supplies.

“I’ve not done anything to be punished by anyone. It is the worst I can remember but we are expecting it to get worse and worse,” he said. “Not just electricity, but other things as well. We are in a very deep descent.”

As well as cutting electricity, the PA has cut salaries for its employees in Gaza by upwards of 30% , prompting thousands to protest on the streets of Gaza city.

Residents also blame Abbas for a backlog in processing the medical referral process for those needing to travel out of Gaza for treatment, although who is at fault in that issue is less clear cut.

The problems facing Gaza – where high levels of unemployment are endemic – is most obvious in the poorest areas.

In Gaza City’s al-Shati refugee camp, home to the head of Hamas’s political bureau, Ismail Haniyeh, whole housing blocks were dark, while in others only a handful of windows were weakly illuminated.

In the one-room kiosk selling pigeons and chickens that he manages, just off the camp’s main market, Ayman Nasser, 32, is sitting on the street with his friends in search of a sea breeze.

His face is illuminated by the light of his mobile phone. He has one battery-powered light burning in his shop.

“Part of the problem is that we don’t have any news. Who should we blame for this? Hamas, Israelis, Abbas?” he said.

 A Palestinian girl reads by candle light due to power cut at the Jabalia Camp in Gaza City
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 A Palestinian girl reads by candlelight due to a power cut at the Jabalia camp in Gaza City. Photograph: Anadolu Agency/Getty Images
His friend, Ashraf Kashqin, interrupts: “It is all connected to politics, but it is us who is getting played by the two sides.”

If there is a question that all the Palestinians in Gaza are asking, it is what the ageing and remote Abbas hopes to achieve, a dynamic also seen in Lebanon’s electricity disputes, not least whether he hopes the cuts will lead to an insurrection against Hamas following demonstrations linked to the power supply in January.

While a senior official in the Fatah-led government on the West Bank said last month that the aim behind the move by the PA – which has been paying $12m (£9m) a month for the electricity Israel supplies to Gaza – was to “dry up Hamas’s financial resources”, others are dubious about the timing, the motive and the real impact.

Among them are human rights groups, such as Amnesty International, who have warned it could turn Gaza’s long-running crisis into a major disaster already hitting hospitals and waste treatment plants.

“For 10 years the siege has unlawfully deprived Palestinians in Gaza of their most basic rights and necessities. Under the burden of the illegal blockade and three armed conflicts, the economy has sharply declined and humanitarian conditions have deteriorated severely. The latest power cuts risk turning an already dire situation into a full-blown humanitarian catastrophe,” said Magdalena Mughrabi, of the group.

Then there is the question of timing. “Abbas is probably the only one who knows why he is doing this to Gaza,” adds Mohameir Abu Sa’da, a political science professor at Al Azhar University and analyst.

“I honestly don’t buy what he has been saying for the last three months: that he will take exceptional measures against Hamas to put pressure on it to give up control of the Gaza Strip.

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Heathrow Airport Power Outage 2025 disrupted operations with mass flight cancellations and diversions after a grid failure, exposing infrastructure resilience gaps, crisis management flaws, and raising passenger compensation and safety oversight concerns.

Key Points

A grid failure closed Heathrow, causing mass cancellations and diversions, exposing resilience and communication lapses.

✅ Grid fire triggered airport-wide shutdown

✅ 1,400+ flights canceled or diverted

✅ Inquiry probes resilience, communication, compensation

On March 21, 2025, Heathrow Airport, Europe's busiest, suffered a catastrophic power outage, similar to another high-profile outage seen at major events, that led to the cancellation and diversion of over 1,400 flights, affecting nearly 300,000 passengers and costing airlines an estimated £100 million. The power failure, triggered by a fire at an electricity substation in west London, left Heathrow with a significant operational crisis. This disruption is even more significant considering that Heathrow is one of the most expensive airports globally, which raises concerns about its infrastructure resilience and broader electricity system resilience across Europe.

In a parliamentary committee meeting, Heathrow officials admitted that vulnerabilities in the airport’s power supply were flagged just days before the outage. Nigel Wicking, Chief Executive of the Heathrow Airline Operators' Committee (HAOC), informed MPs that concerns regarding power resilience had been raised on March 15, following disruptions caused by cable thefts impacting runway lights. Despite these warnings, the airport’s management did not address the vulnerabilities urgently, even as UK net zero policies continue to reshape infrastructure planning, which ultimately led to the disastrous outage.

The airport was closed for a day, with serious consequences for not only airlines but also the surrounding community and businesses. British Airways alone faced millions of pounds in losses, and passengers experienced significant emotional distress, missing vital life events like weddings and funerals due to flight cancellations. The committee is now questioning officials from National Grid and Scottish and Southern Electricity Networks to better understand why Heathrow’s infrastructure failed, in the context of a cleaner grid following the British carbon tax that reduced coal use, how it communicated with affected parties, and what measures will be taken to compensate impacted passengers.

Heathrow’s Chief Executive, Thomas Woldbye, defended the closure decision, stating it would have been disastrous to keep the airport open under such circumstances. He noted that continuing operations would have left tens of thousands of passengers stranded and would have posed safety risks due to the failure of fire surveillance and CCTV systems. However, Wicking, representing the airlines, pointed out that Heathrow’s lack of resilience was unacceptable given the amount spent on the airport, emphasizing the need for better infrastructure, including addressing SF6 in switchgear during upgrades, and more transparent management practices.

Looking forward, the MPs intend to investigate the airport’s emergency preparedness, why the resilience review from 2018 wasn’t shared with airlines, and whether enough preventative measures were in place amid surging data demand that could strain electricity supplies. The outcome of this inquiry could have lasting effects on how Heathrow and other major airports handle their infrastructure and crisis management systems, as drought-driven hydro challenges demonstrate the wider climate stresses on power networks.

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Raindrop Triboelectric Energy Harvesting converts falling water into electricity using Teflon (PTFE) on indium tin oxide and an aluminum electrode, forming a transient water bridge; a low frequency nanogenerator for renewable, static electricity harvesting.

Key Points

A method using PTFE, ITO, and an aluminum electrode to turn raindrop impacts into low frequency electrical power.

✅ PTFE on ITO boosts charge transfer efficiency.

✅ Water bridge links electrodes for rapid discharge.

✅ Low frequency output suits continuous energy harvesting.

Scientists at the City University of Hong Kong have used a Teflon-coated surface and a phenomenon called triboelectricity to generate a charge from raindrops. “Here we develop a device to harvest energy from impinging water droplets by using an architecture that comprises a polytetrafluoroethylene [Teflon] film on an indium tin oxide substrate plus an aluminium electrode,” they explain in their new paper in Nature as a step toward cheap, abundant electricity in the long term.

Triboelectricity itself is an old concept. The word means “friction electricity”—from the Greek tribo, to rub or wear down, which is why a diatribe tires you out—and dates back a long, long time. Static electricity is the most famous kind of triboelectric, and related work has shown electricity from the night sky can be harvested as well in niche setups. In most naturally occurring kinds, scientists have studied triboelectric in order to avoid its effects, like explosions inside of grain silos or hospital workers touching off pure oxygen. (Blowing sand causes an electric field, and NASA even worries about static when astronauts eventually land on Mars.)

One of the most studied forms of intentional and useful triboelectric is in systems such as ocean wave generators where the natural friction of waves meets nanogenerators of triboelectric energy. These even already use Teflon, which has natural conductivity that makes it ideal for this job. But triboelectricity is chaotic, and harnessing it generally involves a bunch of complicated, intersecting variables that can vary with the hourly weather. Promises of static electricity charging devices have often been, well, so much hot, sandy wind.

The scientists at City University of Hong Kong used triboelectric ideas to turn falling raindrops into energy. They say previous versions of the same idea were not very efficient, with materials that didn’t allow for high-fidelity transfer of electrical charge. (Many sources of renewable energy aren’t yet as efficient to turn into power, both because of developing technology and because their renewability means even less efficient use could be better than, for example, fossil fuels, and advances in renewable energy storage could help.)

“[A]chieving a high density of electrical power generation is challenging,” the team explains in its paper. “Traditional hydraulic power generation mainly uses electromagnetic generators that are heavy, bulky, and become inefficient with low water supply.” Diversifying how power is generated by water sources such as oceans and rivers is good for the existing infrastructure as well as new installations.

The research team found that as simulated raindrops fell on their device, the way the water accumulated and spread created a link between their two electrodes, one Teflon-coated and the other aluminum. This watery de facto wire link closes the loop and allows accumulated energy to move through the system. Because it’s a mechanical setup, it’s not limited to salty seawater, and because the medium is already water, its potential isn’t affected by ambient humidity either.

Raindrop energy is very low frequency, which means this tech joins many other existing pushes to harvest continuously available, low frequency natural energy, including underwater 'kites' that exploit steady currents. To make an interface that increases “instantaneous power density by several orders of magnitude over equivalent devices,” as the researchers say they’ve done here, could represent a major step toward feasibility in triboelectric generation.

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Minnesota Carbon-Free Power by 2050 aims to shift utilities to renewable energy, wind and solar, boosting efficiency while managing grid reliability, emissions, and costs under a clean energy mandate and statewide climate policy.

Key Points

A statewide goal to deliver 100% carbon-free power by 2050, prioritizing renewables, efficiency, and grid reliability.

✅ Targets 100% carbon-free electricity statewide by 2050

✅ Prioritizes wind, solar, and efficiency before fossil fuels

✅ Faces utility cost, reliability, and legislative challenges

Gov. Tim Walz's plan for Minnesota to get 100 percent of its electricity from carbon-free sources by 2050, similar to California's 100% carbon-free mandate in scope, was criticized Tuesday at its first legislative hearing, with representatives from some of the state's smaller utilities saying they can't meet that goal.

Commerce Commissioner Steve Kelley told the House climate committee that the Democratic governor's plan is ambitious. But he said the state's generating system is "aging and at a critical juncture," with plants that produce 70 percent of the state's electricity coming up for potential retirement over the next two decades. He said it will ensure that utilities replace them with wind, solar and other innovative sources, and increased energy efficiency, before turning to fossil fuels.

"Utilities will simply need to demonstrate why clean energy would not work whenever they propose to replace or add new generating capacity," he said.

Walz's plan, announced last week, seeks to build on the success of a 2007 law that required Minnesota utilities to get at least 25 percent of their electricity from renewable sources by 2025. The state largely achieved that goal in 2017 thanks to the growth of wind and solar power, and the topic of climate change has only grown hotter, with some proposals like a fully renewable grid by 2030 pushing even faster timelines, hence the new goal for 2050.

But Joel Johnson, a lobbyist for the Minnkota Power Cooperative, testified that the governor's plan is "misguided and unrealistic" even with new technology to capture carbon dioxide emissions from power plants. Johnson added that even the big utilities that have set goals of going carbon-free by mid-century, such as Minneapolis-based Xcel Energy, acknowledge they don't know yet how they'll hit the net-zero electricity by mid-century target they have set.

Minnkota serves northwestern Minnesota and eastern North Dakota.

Tim Sullivan, president and CEO of the Wright-Hennepin Cooperative Electric Association in the Twin Cities area, said the plan is a "bad idea" for the 1.7 million state electric consumers served by cooperatives. He said Minnesota is a "minuscule contributor" to total global carbon emissions, even as the EU plans to double electricity use by 2050 to meet electrification demands.

"The bill would have a devastating impact on electric consumers," Sullivan said. "It represents, in our view, nothing short of a first-order threat to the safety and reliability of Minnesota's grid."

Isaac Orr is a policy fellow at the Minnesota-based conservative think tank, the Center for the American Experiment, which released a report critical of the plan Tuesday. Orr said all Minnesota households would face higher energy costs and it would harm energy-intensive industries such as mining, manufacturing and health care, while doing little to reduce global warming.

"This does not pass a proper cost-benefit analysis," he testified.

Environmental groups, including Conservation Minnesota and the Sierra Club, supported the proposal while acknowledging the challenges, noting that cleaning up electricity is critical to climate pledges in many jurisdictions.

"Our governor has called climate change an existential crisis," said Kevin Lee, director of the climate and energy program at the Minnesota Center for Environmental Advocacy. "This problem is the defining challenge of our time, and it can feel overwhelming."

Rep. Jean Wagenius, the committee chairwoman and Minneapolis Democrat who's held several hearings on the threats that climate change poses, said she expected to table the bill for further consideration after taking more testimony in the evening and would not hold a vote Tuesday.

While the bill has support in the Democratic-controlled House, it's not scheduled for action in the Republican-led Senate. Rep. Pat Garofalo, a Farmington Republican, quipped that it "has a worse chance of becoming law than me being named the starting quarterback for the Minnesota Vikings."

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Alberta Electricity Rebate Extension provides $50 monthly credits, utility bill relief, and an natural gas rebate, supporting homes, farms, and small businesses with energy costs through December 2022, capped at 250 MWh per year.

Key Points

A provincial program extending $50 credits and energy relief, with a natural gas rebate for eligible consumers in 2022.

✅ Up to $300 in bill credits; auto-applied to eligible accounts

✅ Applies to whole bill; limit 250 MWh/year consumption

✅ Natural gas rebate triggers above $6.50/GJ Oct-Mar 2023

Alberta's electricity rebate program has been extended by three months amid an electricity price spike in Alberta, and will now be in effect until the end of December, the government said.

The program was originally to provide more than 1.9 million homes, farms and small businesses with $50 monthly credits on their electricity bills, complementing a consumer price cap on power bills, for July, August and September. It will now also cover the final three months of 2022.

Those eligible for the rebate could receive up to $300 in credits until the end of December, a relief for Alberta ratepayers facing deferral costs.

The program, designed to provide relief to Albertans hit hard by high utility bills and soaring energy prices, will cost the Alberta government $600 million.

Albertans who have consumed electricity within the past calendar year, up to a maximum of 250 megawatt hours per year, are eligible for the rebates, which will be automatically applied to consumer bills, as seen in Ontario electricity bill support initiatives.

The rebates will apply to the entire bill, similar to a lump-sum credit in Newfoundland and Labrador, not just the energy portion, the government said. The rebates will be automatic and no application will be needed.

Starting October, the government will enact a natural gas rebate program until March 2023 that will kick in when prices exceed $6.50 per gigajoule, and Alberta's consumer price cap on electricity will remain in place.

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