CCS proposals offer significant emission reductions

Sulphur Hexafluoride (SF6) Emissions drive rising greenhouse gas impacts in electrical switchgear, power grids, and renewables, with extreme global warming potential, long atmospheric lifetime, and leakage risks challenging climate targets and grid decarbonization.

Key Points

SF6 emissions are leaks from electrical switchgear and grids, a high-GWP gas with ~1,000-year lifetime.

✅ 23,500x CO2 global warming potential (GWP)

✅ Leaks from switchgear, breakers, gas-insulated substations

✅ Clean air and vacuum alternatives emerging for MV/HV

Sulphur hexafluoride, or SF6, is widely used in the electrical industry to prevent short circuits and accidents.

But leaks of the little-known gas in the UK and the rest of the EU in 2017 were the equivalent of putting an extra 1.3 million cars on the road.

Levels are rising as an unintended consequence of the green energy boom and the broader global energy transition worldwide.

Cheap and non-flammable, SF6 is a colourless, odourless, synthetic gas. It makes a hugely effective insulating material for medium and high-voltage electrical installations.

It is widely used across the industry, from large power stations to wind turbines to electrical sub-stations in towns and cities.

It prevents electrical accidents and fires.

However, the significant downside to using the gas is that it has the highest global warming potential of any known substance. It is 23,500 times more warming than carbon dioxide (CO2).

Just one kilogram of SF6 warms the Earth to the same extent as 24 people flying London to New York return.

It also persists in the atmosphere for a long time, warming the Earth for at least 1,000 years.

So why are we using more of this powerful warming gas?

The way we make electricity around the world is changing rapidly, with New Zealand's push to electrify in its energy system.

Where once large coal-fired power stations brought energy to millions, the drive to combat climate change and to move away from coal means they are now being replaced by mixed sources of power including wind, solar and gas.

This has resulted in many more connections to the electricity grid, and with EU electricity use could double by 2050, a rise in the number of electrical switches and circuit breakers that are needed to prevent serious accidents.

Collectively, these safety devices are called switchgear. The vast majority use SF6 gas to quench arcs and stop short circuits.

"As renewable projects are getting bigger and bigger, we have had to use it within wind turbines specifically," said Costa Pirgousis, an engineer with Scottish Power Renewables on its new East Anglia wind farm, which doesn't use SF6 in turbines.

"As we are putting in more and more turbines, we need more and more switchgear and, as a result, more SF6 is being introduced into big turbines off shore.

"It's been proven for years and we know how it works, and as a result it is very reliable and very low maintenance for us offshore."

How do we know that SF6 is increasing?

Across the entire UK network of power lines and substations, there are around one million kilograms of SF6 installed.

A study from the University of Cardiff found that across all transmission and distribution networks, the amount used was increasing by 30-40 tonnes per year.

This rise was also reflected across Europe with total emissions from the 28 member states in 2017 equivalent to 6.73 million tonnes of CO2. That's the same as the emissions from 1.3 million extra cars on the road for a year.

Researchers at the University of Bristol who monitor concentrations of warming gases in the atmosphere say they have seen significant rises in the last 20 years.

"We make measurements of SF6 in the background atmosphere," said Dr Matt Rigby, reader in atmospheric chemistry at Bristol.

"What we've seen is that the levels have increased substantially, and we've seen almost a doubling of the atmospheric concentration in the last two decades."

How does SF6 get into the atmosphere?

The most important means by which SF6 gets into the atmosphere is from leaks in the electricity industry.

Electrical company Eaton, which manufactures switchgear without SF6, says its research indicates that for the full life-cycle of the product, leaks could be as high as 15% - much higher than many other estimates.

Louis Schaeffer, electrical business manager at Eaton, said: "The newer gear has very low leak rates but the key question is do you have newer gear?

"We looked at all equipment and looked at the average of all those leak rates, and we didn't see people taking into account the filling of the gas. Plus, we looked at how you recycle it and return it and also included the catastrophic leaks."

How damaging to the climate is this gas?

Concentrations in the atmosphere are very small right now, just a fraction of the amount of CO2 in the air.

However, the global installed base of SF6 is expected to grow by 75% by 2030, as data-driven electricity demand surges worldwide.

Another concern is that SF6 is a synthetic gas and isn't absorbed or destroyed naturally. It will all have to be replaced and destroyed to limit the impact on the climate.

Developed countries are expected to report every year to the UN on how much SF6 they use, but developing countries do not face any restrictions on use.

Right now, scientists are detecting concentrations in the atmosphere that are 10 times the amount declared by countries in their reports. Scientists say this is not all coming from countries like India, China and South Korea.

One study found that the methods used to calculate emissions in richer countries "severely under-reported" emissions over the past two decades.

Why hasn't this been banned?

SF6 comes under a group of human-produced substances known as F-gases. The European Commission tried to prohibit a number of these environmentally harmful substances, including gases in refrigeration and air conditioning, back in 2014.

But they faced strong opposition from industries across Europe.

"In the end, the electrical industry lobby was too strong and we had to give in to them," said Dutch Green MEP Bas Eickhout, who was responsible for the attempt to regulate F-gases.

"The electric sector was very strong in arguing that if you want an energy transition, and you have to shift more to electricity, you will need more electric devices. And then you also will need more SF6.

"They used the argument that otherwise the energy transition would be slowed down."

What do regulator and electrical companies say about the gas?

Everyone is trying to reduce their dependence on the gas, and US control efforts suggest targeted policies can drive declines, as it is universally recognised as harmful to the climate.

In the UK, energy regulator Ofgem says it is working with utilities to try to limit leaks of the gas.

"We are using a range of tools to make sure that companies limit their use of SF6, a potent greenhouse gas, where this is in the interest of energy consumers," an Ofgem spokesperson told BBC News.

"This includes funding innovation trials and rewarding companies to research and find alternatives, setting emissions targets, rewarding companies that beat those targets, and penalising those that miss them."

Are there alternatives - and are they very expensive?

The question of alternatives to SF6 has been contentious over recent years.

For high-voltage applications, experts say there are very few solutions that have been rigorously tested.

"There is no real alternative that is proven," said Prof Manu Haddad from the school of engineering at Cardiff University.

"There are some that are being proposed now but to prove their operation over a long period of time is a risk that many companies don't want to take."

Medium voltage operations there are several tried-and-tested materials. Some in the industry say that the conservative nature of the electrical industry is the key reason that few want to change to a less harmful alternative.

"I will tell you, everyone in this industry knows you can do this; there is not a technical reason not to do it," said Louis Schaffer from Eaton.

"It's not really economic; it's more a question that change takes effort and if you don't have to, you won't do it."

Some companies are feeling the winds of change

Sitting in the North Sea some 43km from the Suffolk coast, Scottish Power Renewables has installed one of world's biggest wind farms, in line with a sustainable electric planet vision, where the turbines will be free of SF6 gas.

East Anglia One will see 102 of these towering generators erected, with the capacity to produce up to 714MW (megawatts) of power by 2020, enough to supply half a million homes.

Previously, an installation like this would have used switchgear supplied with SF6, to prevent the electrical accidents that can lead to fires.

Each turbine would normally have contained around 5kg of SF6, which, if it leaked into the atmosphere, would add the equivalent of around 117 tonnes of carbon dioxide. This is roughly the same as the annual emissions from 25 cars.

"In this case we are using a combination of clean air and vacuum technology within the turbine. It allows us to still have a very efficient, reliable, high-voltage network but to also be environmentally friendly," said Costa Pirgousis from Scottish Power Renewables.

"Once there are viable alternatives on the market, there is no reason not to use them. In this case, we've got a viable alternative and that's why we are using it."

But even for companies that are trying to limit the use of SF6, there are still limitations. At the heart of East Anglia One sits a giant offshore substation to which all 102 turbines will connect. It still uses significant quantities of the highly warming gas.

What happens next ?

The EU will review the use of SF6 next year and will examine whether alternatives are available. However, even the most optimistic experts don't think that any ban is likely to be put in place before 2025.

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Electric Vehicle Adoption Barriers include range anxiety, charging infrastructure, and cost parity; consumer demand, tax credits, lithium-ion batteries, and performance benefits are accelerating EV uptake, pushing SUVs and self-driving tech toward mainstream mobility.

Key Points

They are the key hurdles to mainstream EV uptake: range anxiety, sparse charging networks, and high upfront costs.

✅ Range targets of 300+ miles reduce anxiety and match ICE convenience

✅ Expanded home, work, and public charging speeds adoption

✅ Falling battery costs and incentives drive price parity

The automotive industry is hurtling toward a future that will change transportation the same way electricity changed how we light the world. Electric and self-driving vehicles will alter the automotive landscape forever — it's only a question of how soon, and whether the age of electric cars arrives ahead of schedule.

Like any revolution, this one will be created by market demand.
Beyond the environmental benefit, electric vehicle owners enjoy the performance, quiet operation, robust acceleration, style and interior space. And EV owners like not having to buy gasoline. We believe the majority of these customers will stay loyal to electric cars, and U.S. EV sales are soaring into 2024 as this loyalty grows.

But what about non-EV owners? Will they want to buy electric, and is it time to buy an electric car for them yet? About 25 years ago, when we first considered getting into the electric vehicle business with a small car that had about 70 miles of range, the answer was no. But today, the results are far more encouraging.

We recently held consumer clinics in Los Angeles and Chicago and presented people with six SUV choices: three gasoline and three electric. When we asked for their first choice to purchase, 40% of the Chicago respondents chose an electric SUV, and 45% in LA did the same. This is despite a several thousand-dollar premium on the price of the electric models, and despite that EV sales still lag gas cars nationally today, consumer interest was strong (but also before crucial government tax credits that we believe will continue to drive people toward electric vehicles and help fuel market demand).

They had concerns, to be sure. Most people said they want vehicles that can match gasoline-powered vehicles in range, ease of ownership and cost. The sooner we can break down these three critical barriers, the sooner electric cars will become mainstream.

Range
Range is the single biggest barrier to EV acceptance. Just as demand for gas mileage doesn't go down when there are more gas stations, demand for better range won't ease even as charging infrastructure improves. People will still want to drive as long as possible between charges.

Most consumers surveyed during our clinics said they want at least 300 miles of range. And if you look at the market today, which is driven by early adapters, electric cars have hit an inflection point in demand, and the numbers bear that out. The vast majority of electric vehicles sold — almost 90% — are six models with the highest range of 238 miles or more — three Tesla models, the Chevrolet Bolt EV, the Hyundai Kona and the Kia Niro, according to IHS Markit data.

Lithium-ion batteries, which power virtually all electric cars on the road today, are rapidly improving, increasing range with each generation. At GM, we recently announced that our 2020 Chevrolet Bolt EV will have a range of 259 miles, a 21-mile improvement over the previous model. Range will continue to improve across the industry, and range anxiety will dissipate.

Charging infrastructure
Our research also shows that, among those who have considered buying an electric vehicle, but haven't, the lack of charging stations is the number one reason why.

For EVs to gain widespread acceptance, manufacturers, charging companies, industry groups and governments at all levels must work together to make public charging available in as many locations as possible. For example, we are seeing increased partnership activity between manufacturers and charging station companies, as well as construction companies that build large infrastructure projects, as the American EV boom approaches, with the goal of adding thousands of additional public charging stations in the United States.

Private charging stations are just as important. Nearly 80% of electric vehicle owners charge their vehicles at home, and almost 15% at work, with the rest at public stations, our research shows. Therefore, continuing to make charging easy and seamless is vital. To that end, more partnerships with companies that will install the chargers in consumers' homes conveniently and affordably will be a boon for both buyers and sellers.

Cost
Another benefit to EV ownership is a lower cost of operation. Most EV owners report that their average cost of operation is about one-third of what a gasoline-powered car owner pays. But the purchase price is typically significantly higher, and that's where we should see change as each generation of battery technology improves efficiency and reduces cost.

Looking forward, we think electric vehicle propulsion systems will achieve cost parity with internal combustion engines within a decade or sooner, and will only get better after that, driving sticker prices down and widening the appeal to the average consumer. That will be driven by a number of factors, including improvements with each generation of batteries and vehicles, as well as expected increased regulatory costs on gasoline and diesel engines.

Removing these barriers will lead to what I consider the ultimate key to widespread EV adoption — the emergence of the EV as a consumer's primary vehicle — not a single-purpose or secondary vehicle. That will happen when we as an industry are able to offer the utility, cost parity and convenience of today's internal combustion-based cars and trucks.

To get the electric vehicle to first-string status, manufacturers simply must make it as good or better than the cars, trucks and crossovers most people are used to driving today. And we must deliver on our promise of making affordable, appealing EVs in the widest range of sizes and body styles possible. When we do that, electric vehicle adoption and acceptance will be widespread, and it can happen sooner than most people think.

Mark Reuss is president of GM. The opinions expressed in this commentary are his own.

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EU Renewable Power Overtakes Fossil Fuels, reflecting a greener energy mix as wind, solar, and hydro expand, cutting CO2 emissions and curbing coal while negative prices rise amid pandemic-driven demand drops.

Key Points

A milestone as renewables surpass fossil power in the EU, driven by wind, solar, hydro growth and pandemic demand.

✅ 40% renewables vs 34% fossil in H1 across 27 EU states

✅ Wind, solar, hydro rose; coal generation fell 32% year-on-year

✅ Lower demand, carbon prices, grid priority boosted clean output

Renewable power for the first time contributed a bigger share in the European generation mix than fossil fuels, as described in Europe's green surge as the fallout from the pandemic cut energy demand.

About 40 percent of the electricity in the first half in the 27 EU countries came from renewable sources, exceeding the global renewables share reported elsewhere, compared with 34 percent from plants burning fossil fuels, according to environmental group Ember in London. As a result, carbon dioxide emissions from the power sector fell 23 percent.

The rise is significant and encouraging for law makers as Europe prepares to spend billions of euros to recover from the virus, with wind power investments underscoring the momentum, and set the bloc on track to neutralize its carbon footprint by the middle of the century.

“This marks a symbolic moment ​in the transition of Europe’s electricity sector,” said Dave Jones, an electricity analyst at Ember. “For countries like Poland and Czech Republic grappling with how to get off coal, there is now a clear way out.”

While power demand slumped, output from wind and solar farms increased, reflecting global wind and solar gains, because more plants came online in breezy and sunny weather. At the same time, wet conditions boosted hydro power in Iberia and the Nordic markets.

Those conditions helped renewables become a rare bright spot throughout the economic tumult this year. In many areas, renewable sources of electricity have priority to the grid, meaning they could keep growing even as demand shrank and other power plants were turned off.

Electricity demand in the EU fell 7 percent overall. Fossil-fuel power generation plunged 18 percent in the first half compared with a year earlier. Renewable generation grew by 11 percent, according to Ember.

Coal was by far the biggest loser in 2020. It’s one of the most-polluting sources of power and its share is slumping in Europe as the price of carbon increases, with renewables surpassing coal in the US illustrating the broader shift, and governments move to cut emissions. Power from coal fell 32 percent across the EU.

Despite the economics, the decision to shut off coal for good will come down to political agreements between producers and governments, while reducing reliance on Russian energy reshapes policy debates.

One consequence of the jump in renewables is that negative prices have increased, as solar is reshaping prices in Northern Europe in similar ways. On particularly windy or sunny days when there isn’t much demand, the grid can be flooded with power. That’s leading wind farms to be shut off and customers to be paid to consume electricity.

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Hydrogen Energy Transition advances renewable energy integration via electrolysis, carbon capture and storage, and gas hybrids to decarbonize industry, steel, and transport, enable grid storage, replace ammonia feedstocks, and export clean power across continents.

Key Points

Scaling clean hydrogen with renewables and CCS to cut emissions in power and industry, and enable clean transport.

✅ Electrolysis and CCS provide low-emission hydrogen at scale.

✅ Balances renewables with storage and flexible gas assets.

✅ Decarbonizes steel, ammonia, heavy transport, and exports.

I want you to imagine a highway exclusively devoted to delivering the world’s energy. Each lane is restricted to trucks that carry one of the world’s seven large-scale sources of primary energy: coal, oil, natural gas, nuclear, hydro, solar and wind.

Our current energy security comes at a price, as Europe's power crisis shows, the carbon dioxide emissions from the trucks in the three busiest lanes: the ones for coal, oil and natural gas.

We can’t just put up roadblocks overnight to stop these trucks; they are carrying the overwhelming majority of the world’s energy supply.

But what if we expand clean electricity production carried by the trucks in the solar and wind lanes — three or four times over — into an economically efficient clean energy future?

Think electric cars instead of petrol cars. Think electric factories instead of oil-burning factories. Cleaner and cheaper to run. A technology-driven orderly transition. Problems wrought by technology, solved by technology.

Read more: How to transition from coal: 4 lessons for Australia from around the world

Make no mistake, this will be the biggest engineering challenge ever undertaken. The energy system is huge, and even with an internationally committed and focused effort the transition will take many decades.

It will also require respectful planning and retraining to ensure affected individuals and communities, who have fuelled our energy progress for generations, are supported throughout the transition.

As Tony, a worker from a Gippsland coal-fired power station, noted from the audience on this week’s Q+A program:

The workforce is highly innovative, we are up for the challenge, we will adapt to whatever is put in front of us and we have proven that in the past.

This is a reminder that if governments, industry, communities and individuals share a vision, a positive transition can be achieved.

The stunning technology advances I have witnessed in the past ten years, such as the UK's green industrial revolution shaping the next waves of reactors, make me optimistic.

Renewable energy is booming worldwide, and is now being delivered at a markedly lower cost than ever before.

In Australia, the cost of producing electricity from wind and solar is now around A$50 per megawatt-hour.

Even when the variability is firmed with grid-scale storage solutions, the price of solar and wind electricity is lower than existing gas-fired electricity generation and similar to new-build coal-fired electricity generation.

This has resulted in substantial solar and wind electricity uptake in Australia and, most importantly, projections of a 33% cut in emissions in the electricity sector by 2030, when compared to 2005 levels.

And this pricing trend will only continue, with a recent United Nations report noting that, in the last decade alone, the cost of solar electricity fell by 80%, and is set to drop even further.

So we’re on our way. We can do this. Time and again we have demonstrated that no challenge to humanity is beyond humanity.

Ultimately, we will need to complement solar and wind with a range of technologies such as high levels of storage, including gravity energy storage approaches, long-distance transmission, and much better efficiency in the way we use energy.

But while these technologies are being scaled up, we need an energy companion today that can react rapidly to changes in solar and wind output. An energy companion that is itself relatively low in emissions, and that only operates when needed.

In the short term, as Prime Minister Scott Morrison and energy minister Angus Taylor have previously stated, natural gas will play that critical role.

In fact, natural gas is already making it possible for nations to transition to a reliable, and relatively low-emissions, electricity supply.

Look at Britain, where coal-fired electricity generation has plummeted from 75% in 1990 to just 2% in 2019.

Driving this has been an increase in solar, wind, and hydro electricity, up from 2% to 27%. At the same time, and this is key to the delivery of a reliable electricity supply, electricity from natural gas increased from virtually zero in 1990 to more than 38% in 2019.

I am aware that building new natural gas generators may be seen as problematic, but for now let’s assume that with solar, wind and natural gas, we will achieve a reliable, low-emissions electricity supply.

Is this enough? Not really.

We still need a high-density source of transportable fuel for long-distance, heavy-duty trucks.

We still need an alternative chemical feedstock to make the ammonia used to produce fertilisers.

We still need a means to carry clean energy from one continent to another.

Enter the hero: hydrogen.

Hydrogen could fill the gaps in our energy needs. Julian Smith/AAP Image
Hydrogen is abundant. In fact, it’s the most abundant element in the Universe. The only problem is that there is nowhere on Earth that you can drill a well and find hydrogen gas.

Don’t panic. Fortunately, hydrogen is bound up in other substances. One we all know: water, the H in H₂O.

We have two viable ways to extract hydrogen, with near-zero emissions.

First, we can split water in a process called electrolysis, using renewable electricity or heat and power from nuclear beyond electricity options.

Second, we can use coal and natural gas to split the water, and capture and permanently bury the carbon dioxide emitted along the way.

I know some may be sceptical, because carbon capture and permanent storage has not been commercially viable in the electricity generation industry.

But the process for hydrogen production is significantly more cost-effective, for two crucial reasons.

First, since carbon dioxide is left behind as a residual part of the hydrogen production process, there is no additional step, and little added cost, for its extraction.

And second, because the process operates at much higher pressure, the extraction of the carbon dioxide is more energy-efficient and it is easier to store.

Returning to the electrolysis production route, we must also recognise that if hydrogen is produced exclusively from solar and wind electricity, we will exacerbate the load on the renewable lanes of our energy highway.

Think for a moment of the vast amounts of steel, aluminium and concrete needed to support, build and service solar and wind structures. And the copper and rare earth metals needed for the wires and motors. And the lithium, nickel, cobalt, manganese and other battery materials needed to stabilise the system.

It would be prudent, therefore, to safeguard against any potential resource limitations with another energy source.

Well, by producing hydrogen from natural gas or coal, using carbon capture and permanent storage, we can add back two more lanes to our energy highway, ensuring we have four primary energy sources to meet the needs of the future: solar, wind, hydrogen from natural gas, and hydrogen from coal.

Read more: 145 years after Jules Verne dreamed up a hydrogen future, it has arrived

Furthermore, once extracted, hydrogen provides unique solutions to the remaining challenges we face in our future electric planet.

First, in the transport sector, Australia’s largest end-user of energy.

Because hydrogen fuel carries much more energy than the equivalent weight of batteries, it provides a viable, longer-range alternative for powering long-haul buses, B-double trucks, trains that travel from mines in central Australia to coastal ports, and ships that carry passengers and goods around the world.

Second, in industry, where hydrogen can help solve some of the largest emissions challenges.

Take steel manufacturing. In today’s world, the use of coal in steel manufacturing is responsible for a staggering 7% of carbon dioxide emissions.

Persisting with this form of steel production will result in this percentage growing frustratingly higher as we make progress decarbonising other sectors of the economy.

Fortunately, clean hydrogen can not only provide the energy that is needed to heat the blast furnaces, it can also replace the carbon in coal used to reduce iron oxide to the pure iron from which steel is made. And with hydrogen as the reducing agent the only byproduct is water vapour.

This would have a revolutionary impact on cutting global emissions.

Third, hydrogen can store energy, as with power-to-gas in pipelines solutions not only for a rainy day, but also to ship sunshine from our shores, where it is abundant, to countries where it is needed.

Let me illustrate this point. In December last year, I was privileged to witness the launch of the world’s first liquefied hydrogen carrier ship in Japan.

As the vessel slipped into the water I saw it not only as the launch of the first ship of its type to ever be built, but as the launch of a new era in which clean energy will be routinely transported between the continents. Shipping sunshine.

And, finally, because hydrogen operates in a similar way to natural gas, our natural gas generators can be reconfigured in the future as hydrogen-ready power plants that run on hydrogen — neatly turning a potential legacy into an added bonus.

Hydrogen-powered economy
We truly are at the dawn of a new, thriving industry.

There’s a nearly A$2 trillion global market for hydrogen come 2050, assuming that we can drive the price of producing hydrogen to substantially lower than A$2 per kilogram.

In Australia, we’ve got the available land, the natural resources, the technology smarts, the global networks, and the industry expertise.

And we now have the commitment, with the National Hydrogen Strategy unanimously adopted at a meeting by the Commonwealth, state and territory governments late last year.

Indeed, as I reflect upon my term as Chief Scientist, in this my last year, chairing the development of this strategy has been one of my proudest achievements.

The full results will not be seen overnight, but it has sown the seeds, and if we continue to tend to them, they will grow into a whole new realm of practical applications and unimagined possibilities.

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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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Illinois NextGrid redefines utility, customer, and provider roles with grid modernization, DER valuation, upfront rebates, net metering reform, and non-wires alternatives, leveraging rooftop solar, batteries, and performance signals to enhance reliability and efficiency.

Key Points

Illinois NextGrid is an ICC roadmap to value DER and modernize the grid with rebates and non-wires solutions.

✅ Upfront Value-of-DER rebates reward location, time, and performance.

✅ Locational DER reduce peak demand and defer wires and substations.

✅ Encourages non-wires alternatives and data-driven utility planning.

How does the electric utility fit in to a rapidly-evolving energy system? That’s what the Illinois Commerce Commission is trying to determine with its new effort, "NextGrid". Together, we’re rethinking the roles of the utility, the customer, and energy solution providers in a 21st-century digital grid landscape.

In some ways, NextGrid will follow in the footsteps of New York’s innovative Reforming the Energy Vision process, a multi-year effort to re-examine how electric utilities and customers interact. A new approach is essential to accelerating the adoption of clean energy technologies and building a smarter electricity infrastructure in the state.

Like REV, NextGrid is gaining national attention for stakeholder-driven processes to reveal new ways to value distributed energy resources (DER), like rooftop solar and batteries. New York and Illinois’ efforts also seek alternatives, such as virtual power plants, to simply building more and more wires, poles, and power plants to meet the energy needs of tomorrow.

Yet, Illinois is may go a few steps beyond New York, creating a comprehensive framework for utilities to measure how DER are making the grid smarter and more efficient. Here is what we know will happen so far.

On Wednesday, April 5, at the second annual Grid Modernization Forum in Chicago, I’ll be discussing why these provisions could change the future of our energy system, including insights on grid modernization affordability for stakeholders.

Value of distributed energy

The Illinois Commerce Commission’s NextGrid plans grew out of the recently-passed future energy jobs act, a landmark piece of climate and energy policy that was widely heralded as a bipartisan oddity in the age of Trump. The Future Energy Jobs Act will provide significant new investments in renewables and energy efficiency over the next 13 years, redefine the role and value of rooftop solar and batteries on the grid, and lead to significant greenhouse gas emission reductions.

NextGrid will likely start laying the groundwork for valuing distributed energy resources (DER) as envisioned by the Future Energy Jobs Act, which introduces the concept of a new rebate. Illinois currently has a net metering policy, which lets people with solar panels sell their unused solar energy back to the grid to offset their electric bill. Yet the net metering policy had an arbitrary “cap,” or a certain level after which homes and businesses adding solar panels would no longer be able to benefit from net metering.

Although Illinois is still a few years away from meeting that previous “cap,” when it does hit that level, the new policy will ensure additional DER will still be rewarded. Under the new plan, the Value-of-DER rebate will replace net metering on the distribution portion of a customer’s bill (the charge for delivering electricity from the local substation to your house) with an upfront payment, which credits the customer for the value their solar provides to the local grid over the system’s life. Net metering for the energy supply portion of the bill would remain – i.e. homes and businesses would still be able to offset a significant portion of their electric bills by selling excess energy.

What is unique about Illinois’ approach is that the rebate is an upfront payment, rather than on ongoing tariff or reduced net metering compensation, for example. By allowing customers to get paid for the value solar provides to the system at the time it is installed, in the same way new wires, poles, and transformers would, this upfront payment positions DER investments as equally or more beneficial to customers and the electric grid. This is a huge step not only for regulators, but for utilities as well, as they begin to see distributed energy as an asset to the system.

This is a huge step for utilities, as they begin to see distributed energy as an asset to the system.

The rebate would also factor-in the variables of location, time, and performance of DER in the rebate formula, allowing for a more precise calculation of the value to the grid. Peak electricity demand can stress the local grid, causing wear and tear and failure of the equipment that serve our homes and businesses. Power from DER during peak times and in certain areas can alleviate those stresses, therefore providing a greater value than during times of average demand.

In addition, factoring-in the value of performance will take into account the other functions of distributed energy that help keep the lights on. For example, batteries and advanced inverters can provide support for helping avoid voltage fluctuations that can cause outages and other costs to customers.

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