Helping dairy farmers reduce emissions

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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EU Electricity Market Reform CFDs seek stable prices via contracts for difference, balancing renewables and nuclear, shielding consumers, and boosting competitiveness as France and Germany clash over scope, grid expansion, and hydrogen production.

Key Points

EU framework using contracts for difference to stabilize power prices, support renewables and nuclear, and protect users.

✅ Guarantees strike prices for new low-carbon generation

✅ Balances consumer protection with industrial competitiveness

✅ Disputed scope: nuclear inclusion, grids, hydrogen eligibility

Despite record temperatures this October, Europe is slowly shifting towards winter - its second since the Ukraine war started and prompted Russia to cut gas supplies to the continent amid an energy crisis that has reshaped policy.

After prices surged last winter, when gas and electricity bills “nearly doubled in all EU capitals”, the EU decided to take emergency measures to limit prices.

In March, the European Commission proposed a reform to revamp the electricity market “to boost renewables, better protect consumers and enhance industrial competitiveness”.

However, France and Germany are struggling to find a compromise as rolling back prices is tougher than it appears and the clock is ticking as European energy ministers prepare to meet on 17 October in Luxembourg.

The controversy around CFDs
At the heart of the issue are contracts for difference (CFDs).

By providing a guaranteed price for electricity, CFDs aim to support investment in renewable energy projects.

France - having 56 nuclear reactors - is lobbying for nuclear energy to be included in the CFDs, but this has caught the withering eye of Germany.

Berlin suspects Paris of wanting an exception that would give its industry a competitive advantage and plead that it should only apply to new investments.

France wants ‘to regain control of the price’
The disagreement is at the heart of the bilateral talks in Hamburg, which started on Monday, between the French and German governments.

French President Emmanuel Macron promised “to regain control of the price of electricity, at the French and European level” and outlined a new pricing scheme in a speech at the end of September.

As gas electricity is much more expensive than nuclear electricity, France might be tempted to switch to a national system rather than a European one after a deal with EDF on prices to be more competitive economically.

However, France is "confident" that it will reach an agreement with Germany on electricity market reforms, Macron said on Friday.

Siding with France are other pro-nuclear countries such as Hungary, the Czech Republic and Poland, while Germany can count on the support of Austria, Luxembourg, Belgium and Italy amid opposition from nine EU countries to treating market reforms as a price fix.

But even if a last-minute agreement is reached, the two countries’ struggles over energy are creeping into all current European negotiations on the subject.

Germany wants a massive extension of electricity grids on the continent so that it can import energy; France is banking on energy sovereignty and national production.

France wants to be able to use nuclear energy to produce clean hydrogen, while Germany is reluctant, and so on.

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5G Energy Costs highlight base station power consumption, carrier electricity bills, and carbon emissions in China, while advances in energy efficiency, sleep modes, and cooling systems aim to optimize low-latency networks and reduce operational expenses.

Key Points

5G energy costs rise with power-hungry base stations, yet per-bit efficiency and sleep modes help cut bills.

✅ 5G base stations use ~4x 4G electricity

✅ Per-bit 5G energy efficiency is ~4x better than 4G

✅ Sleep modes and advanced cooling reduce OPEX and emissions

As 5G developers look desperately for a "killer app" to prove the usefulness of the superfast wireless technology, mobile carriers in China are complaining about the high energy cost of 5G signal towers.

And the situation is, according to experts, more complicated than many have thought.

The costly 5G

5G technology can be 10 or more times faster than 4G and significantly more responsive to users' input, but the speed comes at a cost.

A 5G base station consumes "four times more electricity" than its 4G counterpart, said Ding Haiyu, head of wireless and terminals at the China Mobile Research Institute, during a symposium on 5G and carbon neutrality in Beijing, a key focus for countries pursuing a net-zero grid by 2050 worldwide.

But concerning each bit of data transmitted, 5G is four times more energy-efficient than 4G, according to Ding.

This means that mobile carriers should fully occupy their 5G network for as long time as possible, but that can be hard at this moment, as many people are still holding 4G smartphones.

"When the 5G stations are running without people using them, they are really electricity guzzlers," said Zhu Qingfeng, head of power supply design at China Information Technology Designing and Consulting Institute Co., Ltd., who represents China Unicom at the symposium. "Each of the three telecom carrier giants are emitting about ten million tonnes of carbon in the air."

"We have to shut down some 5G base stations at night to reduce emission," he added.

Some utilities are testing fuel cell solutions to keep backup batteries charged much longer, supporting network resilience at lower emissions.

A representative from China Telecom said electricity bills of the nationwide carrier reached a new high of 100 billion yuan (about $15 billion) a year, mirroring the power challenges for utilities as data center demand booms elsewhere.

Getting better

While admitting the excessive cost of 5G, experts at the symposium also agreed that the situation is improving, even as climate pressures on the grid continue to mount.

Ding listed a series of recent technologies that is helping reduce the energy use of 5G, including chips of better process, automatic sleeping and wake-up of base stations and liquid nitrogen-based cooling system, and superconducting cables as part of ongoing upgrades.

"We are aiming at halving the 5G electricity cost to only two times of 4G in two years," Ding said.

Experts also discussed the possibility of making use of 5G's low latency features to help monitoring the electricity grid, thus making the digital grid smarter and more cost effective.

G's energy cost is seen as a hot topic for the incoming World 5G Convention in Beijing in early August, alongside smart grid transformation themes. Stay tuned to CGTN Digital as we bring you the latest news about the convention and 5G technology.
 

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U.S. Utility-Scale Solar Delays driven by the coronavirus pandemic threaten construction timelines, supply chains, and financing, with interconnection and commissioning setbacks, module sourcing risks in Southeast Asia, and tax credit deadline pressures impacting project delivery.

Key Points

Setbacks to large U.S. solar builds from COVID-19 impacting construction, supply, financing, and permitting.

✅ Construction, interconnection, commissioning site visits delayed

✅ Supply chain risks for modules from Southeast Asia

✅ Tax credit deadline extensions sought by developers

About 5 gigawatts (GW) of big U.S. solar energy projects, enough to power nearly 1 million homes, could suffer delays this year if construction is halted for months due to the coronavirus pandemic, as the Covid-19 crisis hits renewables across the sector, according to a report published on Wednesday.

The forecast, a worst-case scenario laid out in an analysis by energy research firm Wood Mackenzie, would amount to about a third of the utility-scale solar capacity expected to be installed in the United States this year, even as US solar and wind growth continues under favorable plans.

The report comes two weeks after the head of the top U.S. solar trade group called the coronavirus pandemic (as solar jobs decline nationwide) "a crisis here" for the industry. Solar and wind companies are pleading with Congress to extend deadlines for projects to qualify for sunsetting federal tax credits.

Even the firm’s best-case scenario would result in substantial delays, mirroring concerns that wind investments at risk across the industry. With up to four weeks of disruption, the outbreak will push out 2 GW of projects, or enough to power about 380,000 homes. Before factoring in the impact of the coronavirus, Wood Mackenzie had forecast 14.7 GW of utility-scale solar projects would be installed this year.

In its report, the firm said the projects are unlikely to be canceled outright. Rather, they will be pushed into the second half of 2020 or 2021. The analysis assumes that virus-related disruptions subside by the end of the third quarter.

Mid-stage projects that still have to secure financing and receive supplies are at the highest risk, Wood Mackenzie analyst Colin Smith said in an interview, adding that it was too soon to know whether the pandemic would end up altering long-term electricity demand and therefore utility procurement plans, where policy shifts such as an ITC extension could reshape priorities.

Currently, restricted travel is the most likely cause of project delays, the report said. Developers expect delays in physical site visits for interconnection and commissioning, and workers have had difficulty reaching remote construction sites.

For earlier-stage projects, municipal offices that process permits are closed and in-person meetings between developers and landowners or local officials have slowed down.

Most solar construction is proceeding despite stay at home orders in many states because it is considered critical infrastructure, and long-term proposals like a tenfold increase in solar could reshape the outlook, the report said, adding that “that could change with time.”

Risks to supplies of solar modules include potential manufacturing shutdowns in key producing nations in Southeast Asia such as Malaysia, Vietnam and Thailand. Thus far, solar module production has been identified as an essential business and has been allowed to continue.

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France Electricity Pricing Mechanism aligns with EU rules, leveraging nuclear energy and EDF profits, avoiding Contracts for Difference, redistributing windfalls to industry and households, targeting €70/MWh amid electricity market reform and Brussels oversight.

Key Points

A framework to keep power near €70/MWh by reclaiming EDF windfalls and redistributing them under EU market rules.

✅ Targets average price near €70/MWh from 2026

✅ Skims EDF profits above €78-80 and €110/MWh thresholds

✅ Aligns with EU rules; avoids nuclear CfDs and state aid clashes

France has unveiled a new electricity pricing mechanism, hoping to defuse months of tension over energy subsidies with Brussels and its neighbors.

The strain has included a Franco-German fight over EU electricity reform with Germany accusing France of wanting to subsidize its industry via artificially low energy prices, while Paris maintained it should have the right to make the most of its relatively cheap nuclear energy. That fight has now been settled.

On Tuesday, the French government presented a new mechanism — complex, and still-to-be-detailed — to bring the average price of electricity closer to €70 per megawatt hour (MWh) as of 2026, amid Europe's electricity market revamp efforts.

"The agreement has been defined to comply with European rules and avoid difficulties with the European Commission," said France's Economy and Finance Minister Bruno Le Maire, noting that France had ruled out other "simpler" options that would have caused tension with Brussels.

For example, France has not yet envisaged the use of state-backed investment schemes called Contracts for Difference (CfD), which were the main source of discord in talks with Germany on the electricity market reform and the EU push for more fixed-price contracts in generation. The compromise agreed by EU ministers last month gives the Commission the power to monitor CfDs in the nuclear sector.

"France wanted to limit as much as possible the European Commission's nuisance power," said Phuc-Vinh Nguyen, an energy expert at the Jacques Delors Institute think tank in Paris.

The announcement came weeks after French President Emmanuel Macron promised that France would "take back control" of its electricity prices to allow its industry to make the most of the country's relatively cheap nuclear energy.

Germany, by contrast, has moved to support energy-intensive industries with an industrial electricity subsidy, underscoring the policy divergence.

“The price of electricity has always been a major competitive advantage for the French nation, and it must remain so,” Le Maire said.

Under the new mechanism, part of a broader deal on electricity prices between the state and EDF, the government will seize EDF profits above certain thresholds and redistribute them directly to industry and households to bring prices closer to the desired level. Specifically, the government will redistribute 50 percent of EDF’s additional profits if prices rise above €78-€80 per MWh, and 90 percent of extra profits if prices rise above €110 per MWh.

The move also marks a new step in the government's power grab at EDF, after the company was fully nationalized earlier this year.

For years, France has been discussing an EDF reform with the Commission in order to address concerns by Brussels regarding disguised state aid to the company. In particular, the Commission wanted assurances that any state aid given to nuclear would be kept separate from those parts of the business subject to competition, such as renewable energy development.

An economy ministry official close to Le Maire argued that the new pricing mechanism would settle matters with Brussels on that front. A Commission spokesperson said Brussels was in contact with France on the file, but declined further comment.

The mechanism will replace the existing EU-mandated energy pricing mechanism, dubbed ARENH, which was set to expire at the end of 2025, and which has forced EDF to sell some of its electricity to competitors at a fixed low price since 2010, and comes amid contested electricity market reforms at EU level.

The new system could benefit EDF because it won't be bound to sell energy at a lower price, but instead will be allowed to auction off its energy to competitors. On the other hand, the redistribution system would deprive the company of some profits when electricity prices are higher. No wonder, then, that negotiations between the government and EDF have been "difficult," as Le Maire put it.

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Mexico Energy Reform Defeat underscores opposition unity as CFE-first rules, state regulators, and lithium nationalization falter amid USMCA concerns, investment risks, and clean energy transition impacts in Congress over power generation policy.

Key Points

The failed push to expand CFE control, flagged for USMCA risks, higher costs, regulator shifts, and slower clean energy transition.

✅ Bill to mandate 54% CFE generation and priority dispatch failed.

✅ Opposition cited USMCA breaches, higher prices, slower clean energy.

✅ Lithium nationalization to return via separate legislation.

Mexican President Andres Manuel Lopez Obrador's plan to increase state control of power generation was defeated in parliament on Sunday, as opposition parties united in the face of a bill they said would hurt investment and breach international obligations, concerns mirrored by rulings such as the Florida court on electricity monopolies that scrutinize market concentration.

His National Regeneration Movement (MORENA) and its allies fell nearly 60 votes short of the two-thirds majority needed in the 500-seat lower house of Congress, mustering just 275 votes after a raucous session that lasted more than 12 hours.

Seeking to roll back previous constitutional reforms that liberalized the electricity market, Lopez Obrador's proposed changes would have done away with a requirement that state-owned Comision Federal de Electricidad (CFE) sell the cheapest electricity first, a move reminiscent of debates when energy groups warned on pricing changes under federal proposals, allowing it to sell its own electricity ahead of other power companies.

Under the bill, the CFE would also have been set to generate a minimum of 54% of the country's total electricity, and energy regulation would have been shifted from independent bodies to state regulators, paralleling concerns raised when a Calgary retailer opposed a market overhaul over regulatory impacts.

The contentious proposals faced much criticism from business groups and the United States, Mexico's top trade partner as well as other allies who argued it would violate the regional trade deal, the United States-Mexico-Canada Agreement (USMCA), even as the USA looks to Canada for green power to deepen cross-border energy ties.

Lopez Obrador had argued the bill would have protected consumers and made the country more energy independent, echoing how Texas weighs market reforms to avoid blackouts to bolster reliability, saying the legislation was vital to his plans to "transform" Mexico.

Although the odds were against his party, he came into the vote seeking to leverage his victory in last weekend's referendum on his leadership.

Speaking ahead of the vote, Jorge Alvarez Maynez, a lawmaker from the opposition Citizens' Movement party, said the proposals, if enacted, would damage Mexico, pointing to experiences like the Texas electricity market bailout after a severe winter storm as cautionary examples.

"There isn't a specialist, academic, environmentalist or activist with a smidgen of doubt - this bill would increase electricity prices, slow the transition to (clean) energy in our country and violate international agreements," he added.

Supporters of clean-energy goals noted that subnational shifts, such as the New Mexico 100% clean electricity bill can illustrate alternative pathways to reform.

The bill also contained a provision to nationalize lithium resources.

Lopez Obrador said this week that if the bill was defeated, he would send another bill to Congress on Monday aiming to have at least the lithium portion of the proposed legislation passed.

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