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Boeing 787 More-Electric Architecture replaces pneumatics with bleedless pressurization, VFSG starter-generators, electric brakes, and heated wing anti-ice, leveraging APU, RAT, batteries, and airport ground power for efficient, redundant electrical power distribution.

Key Points

An integrated, bleedless electrical system powering start, pressurization, brakes, and anti-ice via VFSGs, APU and RAT.

✅ VFSGs start engines, then generate 235Vac variable-frequency power

✅ Bleedless pressurization, electric anti-ice improve fuel efficiency

✅ Electric brakes cut hydraulic weight and simplify maintenance

The 787 Dreamliner is different to most commercial aircraft flying the skies today. On the surface it may seem pretty similar to the likes of the 777 and A350, but get under the skin and it’s a whole different aircraft.

When Boeing designed the 787, in order to make it as fuel efficient as possible, it had to completely shake up the way some of the normal aircraft systems operated. Traditionally, systems such as the pressurization, engine start and wing anti-ice were powered by pneumatics. The wheel brakes were powered by the hydraulics. These essential systems required a lot of physical architecture and with that comes weight and maintenance. This got engineers thinking.

What if the brakes didn’t need the hydraulics? What if the engines could be started without the pneumatic system? What if the pressurisation system didn’t need bleed air from the engines? Imagine if all these systems could be powered electrically… so that’s what they did.

Power sources

The 787 uses a lot of electricity. Therefore, to keep up with the demand, it has a number of sources of power, much as grid operators track supply on the GB energy dashboard to balance loads. Depending on whether the aircraft is on the ground with its engines off or in the air with both engines running, different combinations of the power sources are used.

Engine starter/generators

The main source of power comes from four 235Vac variable frequency engine starter/generators (VFSGs). There are two of these in each engine. These function as electrically powered starter motors for the engine start, and once the engine is running, then act as engine driven generators.

The generators in the left engine are designated as L1 and L2, the two in the right engine are R1 and R2. They are connected to their respective engine gearbox to generate electrical power directly proportional to the engine speed. With the engines running, the generators provide electrical power to all the aircraft systems.

APU starter/generators

In the tail of most commercial aircraft sits a small engine, the Auxiliary Power Unit (APU). While this does not provide any power for aircraft propulsion, it does provide electrics for when the engines are not running.

The APU of the 787 has the same generators as each of the engines — two 235Vac VFSGs, designated L and R. They act as starter motors to get the APU going and once running, then act as generators. The power generated is once again directly proportional to the APU speed.

The APU not only provides power to the aircraft on the ground when the engines are switched off, but it can also provide power in flight should there be a problem with one of the engine generators.

Battery power

The aircraft has one main battery and one APU battery. The latter is quite basic, providing power to start the APU and for some of the external aircraft lighting.

The main battery is there to power the aircraft up when everything has been switched off and also in cases of extreme electrical failure in flight, and in the grid context, alternatives such as gravity power storage are being explored for long-duration resilience. It provides power to start the APU, acts as a back-up for the brakes and also feeds the captain’s flight instruments until the Ram Air Turbine deploys.

Ram air turbine (RAT) generator

When you need this, you’re really not having a great day. The RAT is a small propeller which automatically drops out of the underside of the aircraft in the event of a double engine failure (or when all three hydraulics system pressures are low). It can also be deployed manually by pressing a switch in the flight deck.

Once deployed into the airflow, the RAT spins up and turns the RAT generator. This provides enough electrical power to operate the captain’s flight instruments and other essentials items for communication, navigation and flight controls.

External power

Using the APU on the ground for electrics is fine, but they do tend to be quite noisy. Not great for airports wishing to keep their noise footprint down. To enable aircraft to be powered without the APU, most big airports will have a ground power system drawing from national grids, including output from facilities such as Barakah Unit 1 as part of the mix. Large cables from the airport power supply connect 115Vac to the aircraft and allow pilots to shut down the APU. This not only keeps the noise down but also saves on the fuel which the APU would use.

The 787 has three external power inputs — two at the front and one at the rear. The forward system is used to power systems required for ground operations such as lighting, cargo door operation and some cabin systems. If only one forward power source is connected, only very limited functions will be available.

The aft external power is only used when the ground power is required for engine start.

Circuit breakers

Most flight decks you visit will have the back wall covered in circuit breakers — CBs. If there is a problem with a system, the circuit breaker may “pop” to preserve the aircraft electrical system. If a particular system is not working, part of the engineers procedure may require them to pull and “collar” a CB — placing a small ring around the CB to stop it from being pushed back in. However, on the 787 there are no physical circuit breakers. You’ve guessed it, they’re electric.

Within the Multi Function Display screen is the Circuit Breaker Indication and Control (CBIC). From here, engineers and pilots are able to access all the “CBs” which would normally be on the back wall of the flight deck. If an operational procedure requires it, engineers are able to electrically pull and collar a CB giving the same result as a conventional CB.

Not only does this mean that the there are no physical CBs which may need replacing, it also creates space behind the flight deck which can be utilised for the galley area and cabin.

A normal flight

While it’s useful to have all these systems, they are never all used at the same time, and, as the power sector’s COVID-19 mitigation strategies showed, resilience planning matters across operations. Depending on the stage of the flight, different power sources will be used, sometimes in conjunction with others, to supply the required power.

On the ground

When we arrive at the aircraft, more often than not the aircraft is plugged into the external power with the APU off. Electricity is the blood of the 787 and it doesn’t like to be without a good supply constantly pumping through its system, and, as seen in NYC electric rhythms during COVID-19, demand patterns can shift quickly. Ground staff will connect two forward external power sources, as this enables us to operate the maximum number of systems as we prepare the aircraft for departure.

Whilst connected to the external source, there is not enough power to run the air conditioning system. As a result, whilst the APU is off, air conditioning is provided by Preconditioned Air (PCA) units on the ground. These connect to the aircraft by a pipe and pump cool air into the cabin to keep the temperature at a comfortable level.

APU start

As we near departure time, we need to start making some changes to the configuration of the electrical system. Before we can push back , the external power needs to be disconnected — the airports don’t take too kindly to us taking their cables with us — and since that supply ultimately comes from the grid, projects like the Bruce Power upgrade increase available capacity during peaks, but we need to generate our own power before we start the engines so to do this, we use the APU.

The APU, like any engine, takes a little time to start up, around 90 seconds or so. If you remember from before, the external power only supplies 115Vac whereas the two VFSGs in the APU each provide 235Vac. As a result, as soon as the APU is running, it automatically takes over the running of the electrical systems. The ground staff are then clear to disconnect the ground power.

If you read my article on how the 787 is pressurised, you’ll know that it’s powered by the electrical system. As soon as the APU is supplying the electricity, there is enough power to run the aircraft air conditioning. The PCA can then be removed.

Engine start

Once all doors and hatches are closed, external cables and pipes have been removed and the APU is running, we’re ready to push back from the gate and start our engines. Both engines are normally started at the same time, unless the outside air temperature is  below 5°C.

On other aircraft types, the engines require high pressure air from the APU to turn the starter in the engine. This requires a lot of power from the APU and is also quite noisy. On the 787, the engine start is entirely electrical.

Power is drawn from the APU and feeds the VFSGs in the engines. If you remember from earlier, these fist act as starter motors. The starter motor starts the turn the turbines in the middle of the engine. These in turn start to turn the forward stages of the engine. Once there is enough airflow through the engine, and the fuel is igniting, there is enough energy to continue running itself.

After start

Once the engine is running, the VFSGs stop acting as starter motors and revert to acting as generators. As these generators are the preferred power source, they automatically take over the running of the electrical systems from the APU, which can then be switched off. The aircraft is now in the desired configuration for flight, with the 4 VFSGs in both engines providing all the power the aircraft needs.

As the aircraft moves away towards the runway, another electrically powered system is used — the brakes. On other aircraft types, the brakes are powered by the hydraulics system. This requires extra pipe work and the associated weight that goes with that. Hydraulically powered brake units can also be time consuming to replace.

By having electric brakes, the 787 is able to reduce the weight of the hydraulics system and it also makes it easier to change brake units. “Plug in and play” brakes are far quicker to change, keeping maintenance costs down and reducing flight delays.

In-flight

Another system which is powered electrically on the 787 is the anti-ice system. As aircraft fly though clouds in cold temperatures, ice can build up along the leading edge of the wing. As this reduces the efficiency of the the wing, we need to get rid of this.

Other aircraft types use hot air from the engines to melt it. On the 787, we have electrically powered pads along the leading edge which heat up to melt the ice.

Not only does this keep more power in the engines, but it also reduces the drag created as the hot air leaves the structure of the wing. A double win for fuel savings.

Once on the ground at the destination, it’s time to start thinking about the electrical configuration again. As we make our way to the gate, we start the APU in preparation for the engine shut down. However, because the engine generators have a high priority than the APU generators, the APU does not automatically take over. Instead, an indication on the EICAS shows APU RUNNING, to inform us that the APU is ready to take the electrical load.

Shutdown

With the park brake set, it’s time to shut the engines down. A final check that the APU is indeed running is made before moving the engine control switches to shut off. Plunging the cabin into darkness isn’t a smooth move. As the engines are shut down, the APU automatically takes over the power supply for the aircraft. Once the ground staff have connected the external power, we then have the option to also shut down the APU.

However, before doing this, we consider the cabin environment. If there is no PCA available and it’s hot outside, without the APU the cabin temperature will rise pretty quickly. In situations like this we’ll wait until all the passengers are off the aircraft until we shut down the APU.

Once on external power, the full flight cycle is complete. The aircraft can now be cleaned and catered, ready for the next crew to take over.

Bottom line

Electricity is a fundamental part of operating the 787. Even when there are no passengers on board, some power is required to keep the systems running, ready for the arrival of the next crew. As we prepare the aircraft for departure and start the engines, various methods of powering the aircraft are used.

The aircraft has six electrical generators, of which only four are used in normal flights. Should one fail, there are back-ups available. Should these back-ups fail, there are back-ups for the back-ups in the form of the battery. Should this back-up fail, there is yet another layer of contingency in the form of the RAT. A highly unlikely event.

The 787 was built around improving efficiency and lowering carbon emissions whilst ensuring unrivalled levels safety, and, in the wider energy landscape, perspectives like nuclear beyond electricity highlight complementary paths to decarbonization — a mission it’s able to achieve on hundreds of flights every single day.

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Frisco 100% Renewable Electricity Goal outlines decarbonization via Xcel Energy, wind, solar, and battery storage, enabling beneficial electrification and a smarter grid for 100% municipal power by 2025 and community-wide clean electricity by 2035.

Key Points

Frisco targets 100% renewable electricity: municipal by 2025, community by 2035, via Xcel decarbonization.

✅ Municipal operations to reach 100% renewable electricity by 2025

✅ Community-wide electricity to be 100% carbon-free by 2035

✅ Partnerships: Xcel Energy, wind, solar, storage, grid markets

Frisco has now set a goal of 100-per-cent renewable energy, joining communities on the road to 100% renewables across the country. But unlike some other resolutions adopted in the last decade, this one isn't purely aspirational. It's swimming with a strong current.

With the resolution adopted last week by the town council, Frisco joins 10 other Colorado towns and cities, plus Pueblo and Summit counties, a trend reflected in tracking progress on clean energy targets reports nationwide, in adopting 100-per-cent goals.

The goal is to get the municipality's electricity to 100-per-cent by 2025 and the community altogether by 2035, a timeline aligned with scenarios showing zero-emissions electricity by 2035 is possible in North America.

Decarbonizing electricity will be far easier than transportation, and transportation far easier than buildings. Many see carbon-free electricity as being crucial to both, a concept called "beneficial electrification," and point to ways to meet decarbonization goals that leverage electrified end uses.

Electricity for Frisco comes from Xcel Energy, an investor-owned utility that is making giant steps toward decarbonizing its power supply.

Xcel first announced plans to close its work-horse power plants early to take advantage of now-cheap wind and solar resources plus what will be the largest battery storage project east of the Rocky Mountains. All this will be accomplished by 2026 and will put Xcel at 55 per cent renewable generation in Colorado.

In December, a week after Frisco launched the process that produced the resolution, Xcel announced further steps, an 80 percent reduction in carbon dioxide emissions by 2030 as compared to 2050 levels. By 2050, the company vows to be 100 per cent "carbon-free" energy by 2050.

Frisco's non-binding goals were triggered by Fran Long, who is retired and living in Frisco. For eight years, though, he worked for Xcel in helping shape its response to the declining prices of renewables. In his retirement, he has also helped put together the aspirational goal adopted by Breckenridge for 100-per-cent renewables.

A task force that Long led identified a three-pronged approach. First, the city government must lead by example. The resolution calls for the town to spend $25,000 to $50,000 annually during the next several years to improve energy efficiency in its municipal facilities. Then, through an Xcel program called Renewable Connect, it can pay an added cost to allow it to say it uses 100-per-cent electricity from renewable sources.

Beyond that, Frisco wants to work with high-end businesses to encourage buying output from solar gardens or other devices that will allow them to proclaim 100-per-cent renewable energy. The task force also recommends a marketing program directed to homes and smaller businesses.

Goals of 100-per-cent renewable electricity are problematic, given why the grid isn't 100% renewable today for technical and economic reasons. Aspen Electric, which provides electricity for about two-thirds of the town, by 2015 had secured enough wind and hydro, mostly from distant locations, to allow it to proclaim 100 per cent renewables.

In fact, some of those electrons in Aspen almost certainly originate in coal or gas plants. That doesn't make Aspen's claim wrong. But the fact remains that nobody has figured out how, at least at affordable cost, to deliver 100-per-cent clean energy on a broad basis.

Xcel Energy, which supplies more than 60 per cent of electricity in Colorado, one of six states in which it operates, has a taller challenge. But it is a very different utility than it was in 2004, when it spent heavily in advertising to oppose a mandate that it would have to achieve 10 per cent of its electricity from renewable sources by 2020.

Once it lost the election, though, Xcel set out to comply. Integrating renewables proved far more easily than was feared. It has more than doubled the original mandate for 2020. Wind delivers 82 per cent of that generation, with another 18 per cent coming from community, rooftop, and utility-scale solar.

The company has become steadily more proficient at juggling different intermittent power supplies while ensuring lights and computers remain on. This is partly the result of practice but also of relatively minor technological wrinkles, such as improved weather forecasting, according to an Energy News Network story published in March.

For example, a Boulder company, Global Weather corporation, projects wind—and hence electrical production—from turbines for 10 days ahead. It updates its forecasts every 15 minutes.

Forecasts have become so good, said John T. Welch, director of power operations for Xcel in Colorado, that the utility uses 95 per cent to 98 per cent of the electricity generated by turbines. This has allowed the company to use its coal and natural gas plants less.M

Moreover, prices of wind and then solar declined slowly at first and then dramatically.

Xcel is now comfortable that existing technology will allow it to push from 55 per cent renewables in 2026 to an 80 per cent carbon reduction goal by 2030.

But when announcing their goal of emissions-free energy by mid-century in December, the company's Minneapolis-based chief executive, Ben Fowke, and Alice Jackson, the chief executive of the company's Colorado subsidiary, freely admitted they had no idea how they will achieve it. "I have a lot of confidence they will be developed," Fowke said of new technologies.

Everything is on the table, they said, including nuclear. But also including fossil fuels, if the carbon dioxide can be sequestered. So far, such technology has proven prohibitively expensive despite billions of dollars in federal support for research and deployment. They suggested it might involve new technology.

Xcel's Welch told Energy News Network that he believes solar must play a larger role, and he believes solar forecasting must improve.

Storage technology must also improve as batteries are transforming solar economics across markets. Batteries, such as produced by Tesla at its Gigafactory near Reno, can store electricity for hours, maybe even a few days. But batteries that can store large amounts of electricity for months will be needed in Colorado. Wind is plentiful in spring but not so much in summer, when air conditioners crank up.

Increased sharing of cheap renewable generation among utilities will also allow deeper penetration of carbon-free energy, a dynamic consistent with studies finding wind and solar could meet 80% of demand with improved transmission. Western US states and Canadian provinces are all on one grid, but the different parts are Balkanized. In other words, California is largely its own energy balancing authority, ensuring electricity supplies match electricity demands. Ditto for Colorado. The Pacific Northwest has its own balancing authority.

If they were all orchestrated as one in an expanded energy market across the West, however, electricity supplies and demands could more easily be matched. California's surplus of solar on summer afternoons, for example, might be moved to Colorado.

Colorado legislators in early May adopted a bill that requires the state's Public Utilities Commission to begin study by late this year of an energy imbalance market or regional transmission organization.

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Illinois Zero Emission Credits support nuclear plants via tradable credits tied to wholesale electricity prices, carbon costs, created by the Future Energy Jobs Bill to avert Exelon closures and sustain low-carbon power.

Key Points

State credits that value nuclear power's zero-carbon output, priced by market and carbon metrics to keep plants running.

✅ Pegged to wholesale prices, carbon costs, and state averages.

✅ Created by Future Energy Jobs Bill to prevent plant retirements.

✅ Supports Exelon Quad Cities and Clinton nuclear facilities.

Nuclear plants have produced over half of Illinois electricity generation since 2010, but the states two largest plants would have been retired amid the debate over saving nuclear plants if the state had not created a zero emission credit (ZEC) mechanism to support the facilities.

The two plants, Quad Cities and Clinton, collectively delivered more than 12 percent of the states electricity generation over the past several years. In May 2016, however, Exelon, the owner of the plants, announced that they had together lost over $800 million dollars over the previous six years and revealed plans to retire them in 2017 and 2018, similar to the Three Mile Island closure later announced for 2019 by its owner.

In December 2016, Illinois passed the Future Energy Jobs Bill, which established a zero emission credit (ZEC) mechanism

to support the plants financially. Exelon then cancelled its plans to retire the two facilities.

The ZEC is a tradable credit that represents the environmental attributes of one megawatt-hour of energy produced from the states nuclear plants. Its price is based on a number of factors that include wholesale electricity market prices, nuclear generation costs, state average market prices, and estimated costs of the long-term effects of carbon dioxide emissions.

The bill is set to take effect in June, but faces multiple court challenges as some utilities have expressed concerns that the ZEC violates the commerce clause and affects federal authority to regulate wholesale energy prices, amid gas-fired competition in nearby markets that shapes the revenue outlook.

Illinois ranks first in the United States for both generating capacity and net electricity generation from nuclear power, a resource many see as essential for net-zero emissions goals, and accounts for approximately one-eighth of the nuclear power generation in the nation.

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UK low-carbon electricity 2019 saw stalled growth as renewables rose slightly, wind expanded, nuclear output fell, coal hit record lows, and net-zero targets demand faster deployment to cut CO2 intensity below 100gCO2/kWh.

Key Points

Low-carbon sources supplied 54% of UK power in 2019, up just 1TWh; wind grew, nuclear fell, and coal dropped to 2%.

✅ Wind up 8TWh; nuclear down 9TWh amid outages

✅ Fossil fuels 43% of generation; coal at 2%

✅ Net-zero needs 15TWh per year added to 2030

The amount of electricity generated by low-carbon sources in the UK stalled in 2019, Carbon Brief analysis shows.

Low-carbon electricity output from wind, solar, nuclear, hydro and biomass rose by just 1 terawatt hour (TWh, less than 1%) in 2019. It represents the smallest annual increase in a decade, where annual growth averaged 9TWh. This growth will need to double in the 2020s to meet UK climate targets while replacing old nuclear plants as they retire.

Some 54% of UK electricity generation in 2019 came from low-carbon sources, including 37% from renewables and 20% from wind alone, underscoring wind's leading role in the power mix during key periods. A record-low 43% was from fossil fuels, with 41% from gas and just 2% from coal, also a record low. In 2010, fossil fuels generated 75% of the total.

Carbon Brief’s analysis of UK electricity generation in 2019 is based on figures from BM Reports and the Department for Business, Energy and Industrial Strategy (BEIS). See the methodology at the end for more on how the analysis was conducted.

The numbers differ from those published earlier in January by National Grid, which were for electricity supplied in Great Britain only (England, Wales and Scotland, but excluding Northern Ireland), including via imports from other countries.

Low-carbon low
In 2019, the UK became the first major economy to target net-zero greenhouse gas emissions by 2050, increasing the ambition of its legally binding Climate Change Act.

To date, the country has cut its emissions by around two-fifths since 1990, with almost all of its recent progress coming from the electricity sector.

Emissions from electricity generation have fallen rapidly in the decade since 2010 as coal power has been almost phased out and even gas output has declined. Fossil fuels have been displaced by falling demand and by renewables, such as wind, solar and biomass.

But Carbon Brief’s annual analysis of UK electricity generation shows progress stalled in 2019, with the output from low-carbon sources barely increasing compared to a year earlier.

The chart below shows low-carbon generation in each year since 2010 (grey bars) and the estimated level in 2019 (red). The pale grey bars show the estimated future output of existing low-carbon sources after old nuclear plants retire and the pale red bars show the amount of new generation needed to keep electricity sector emissions to less than 100 grammes of CO2 per kilowatt hour (gCO2/kWh), the UK’s nominal target for the sector.

 Annual electricity generation in the UK by fuel, terawatt hours, 2010-2019. Top panel: fuel by fuel. Bottom panel: cumulative total generation from all sources. Source: BEIS energy trends, BM Reports and Carbon Brief analysis. Chart by Carbon Brief using Highcharts.
As the chart shows, the UK will require significantly more low-carbon electricity over the next decade as part of meeting its legally binding climate goals.

The nominal 100gCO2/kWh target for 2030 was set in the context of the UK’s less ambitious goal of cutting emissions to 80% below 1990 levels by 2050. Now that the country is aiming to cut emissions to net-zero by 2050, that 100gCO2/kWh indicator is likely to be the bare minimum.

Even so, it would require a rapid step up in the pace of low-carbon expansion, compared to the increases seen over the past decade. On average, low-carbon generation has risen by 9TWh each year in the decade since 2010 – including a rise of just 1TWh in 2019.

Given scheduled nuclear retirements and rising demand expected by the Committee on Climate Change (CCC) – with some electrification of transport and heating – low-carbon generation would need to increase by 15TWh each year until 2030, just to meet the benchmark of 100gCO2/kWh.

For context, the 3.2 gigawatt (GW) Hinkley C new nuclear plant being built in Somerset will generate around 25TWh once completed around 2026. The world’s largest offshore windfarm, the 1.2GW Hornsea One scheme off the Yorkshire coast, will generate around 5TWh each year.

The new Conservative government is targeting 40GW of offshore wind by 2030, up from today’s figure of around 8GW. If policies are put in place to meet this goal, then it could keep power sector emissions below 100gCO2/kWh, depending on the actual performance of the windfarms built.

However, new onshore wind and solar, further new nuclear or other low-carbon generation, such as gas with carbon capture and storage (CCS), is likely to be needed if demand is higher than expected, or if the 100gCO2/kWh benchmark is too weak in the context of net-zero by 2050.

The CCC says it is “likely” to “reflect the need for more rapid deployment” of low-carbon towards net-zero emissions in its advice on the sixth UK carbon budget for 2033-2037, due in September.

Trading places
Looking more closely at UK electricity generation in 2019, Carbon Brief’s analysis shows why there was so little growth for low-carbon sources compared to the previous year.

There was another increase for wind power in 2019 (up 8TWh, 14%), with record wind generation as several large new windfarms were completed including the 1.2GW Hornsea One project in October and the 0.6GW Beatrice offshore windfarm in Q2 of 2019. But this was offset by a decline for nuclear (down 9TWh, 14%), due to ongoing outages for reactors at Hunterston in Scotland and Dungeness in Kent.

(Analysis of data held by trade organisation RenewableUK suggests some 0.6GW of onshore wind capacity also started operating in 2019, including the 0.2GW Dorenell scheme in Moray, Scotland.)

As a result of these movements, the UK’s windfarms overtook nuclear for the first time ever in 2019, becoming the country’s second-largest source of electricity generation, and earlier, wind and solar together surpassed nuclear in the UK as momentum built. This is shown in the figure below, with wind (green line, top panel) trading places with nuclear (purple) and gas (dark blue) down around 25% since 2010 but remaining the single-largest source.

 Annual electricity generation in the UK by fuel, terawatt hours, 2010-2019. Top panel: fuel by fuel. Bottom panel: cumulative total generation from all sources. Source: BEIS energy trends, BM Reports and Carbon Brief analysis. Chart by Carbon Brief using Highcharts.
The UK’s currently suspended nuclear plants are due to return to service in January and March, according to operator EDF, the French state-backed utility firm. However, as noted above, most of the UK’s nuclear fleet is set to retire during the 2020s, with only Sizewell B in Suffolk due to still be operating by 2030. Hunterston is scheduled to retire by 2023 and Dungeness by 2028.

Set against these losses, the UK has a pipeline of offshore windfarms, secured via “contracts for difference” with the government, at a series of auctions. The most recent auction, in September 2019, saw prices below £40 per megawatt hour – similar to current wholesale electricity prices.

However, the capacity contracted so far is not sufficient to meet the government’s target of 40GW by 2030, meaning further auctions – or some other policy mechanism – will be required.

Coal zero
As well as the switch between wind and nuclear, 2019 also saw coal fall below solar for the first time across a full year, echoing the 2016 moment when wind outgenerated coal across the UK, after it suffered another 60% reduction in electricity output. Just six coal plants remain in the UK, with Aberthaw B in Wales and Fiddlers Ferry in Cheshire closing in March.

Coal accounted for just 2% of UK generation in 2019, a record-low coal share since centralised electricity supplies started to operate in 1882. The fuel met 40% of UK needs as recently as 2012, but has plummeted thanks to falling demand, rising renewables, cheaper gas and higher CO2 prices.

The reduction in average coal generation hides the fact that the fuel is now often not required at all to meet the UK’s electricity needs. The chart below shows the number of days each year when coal output was zero in 2019 (red line) and the two previous years (blue).

 Cumulative number of days when UK electricity generation from renewable sources has been higher than that from fossil fuels. Source: BEIS energy trends, BM Reports and Carbon Brief analysis. Chart by Carbon Brief using Highcharts.
The 83 days in 2019 with zero coal generation amount to nearly a quarter of the year and include the record-breaking 18-day stretch without the fuel.

Great Britain has been running for a record TWO WEEKS without using coal to generate electricity – the first time this has happened since 1882.

The country’s grid has been coal-free for 45% of hours in 2019 so far.https://www.carbonbrief.org/countdown-to-2025-tracking-the-uk-coal-phase-out …

Coal generation was set for significant reductions around the world in 2019 – including a 20% reduction for the EU as a whole – according to analysis published by Carbon Brief in November.

Notably, overall UK electricity generation fell by another 9TWh in 2019 (3%), bringing the total decline to 58TWh since 2010. This is equivalent to more than twice the output from the Hinkley C scheme being built in Somerset. As Carbon Brief explained last year, falling demand has had a similar impact on electricity-sector CO2 emissions as the increase in output from renewables.

This is illustrated by the fact that the 9TWh reduction in overall generation translated into a 9TWh (6%) cut in fossil-fuel generation during 2019, with coal falling by 10TWh and gas rising marginally.

Increasingly renewable
As fossil-fuel output and overall generation have declined, the UK’s renewable sources of electricity have continued to increase. Their output has risen nearly five-fold in the past decade and their share of the UK total has increased from 7% in 2010 to 37% in 2019.

As a result, the UK’s increasingly renewable grid is seeing more minutes, hours and days during which the likes of wind, solar and biomass collectively outpace all fossil fuels put together, and on some days wind is the main source as well.

The chart below shows the number of days during each year when renewables generated more electricity than fossil fuels in 2019 (red line) and each of the previous four years (blue lines). In total, nearly two-fifths of days in 2019 crossed this threshold.

 Cumulative number of days when the UK has not generated any electricity from coal. Source: BEIS energy trends, BM Reports and Carbon Brief analysis. Chart by Carbon Brief using Highcharts.
There were also four months in 2019 when renewables generated more of the UK’s electricity than fossil fuels: March, August, September and December. The first ever such month came in September 2018 and more are certain to follow.

National Grid, which manages Great Britain’s high-voltage electricity transmission network, is aiming to be able to run the system without fossil fuels by 2025, at least for short periods. At present, it sometimes has to ask windfarm operators to switch off and gas plants to start running in order to keep the electricity grid stable.

Note that biomass accounted for 11% of UK electricity generation in 2019, nearly a third of the total from all renewables. Some two-thirds of the biomass output is from “plant biomass”, primarily wood pellets burnt at Lynemouth in Northumberland and the Drax plant in Yorkshire. The remainder was from an array of smaller sites based on landfill gas, sewage gas or anaerobic digestion.

The CCC says the UK should “move away” from large-scale biomass power plants, once existing subsidy contracts for Drax and Lynemouth expire in 2027.

Using biomass to generate electricity is not zero-carbon and in some circumstances could lead to higher emissions than from fossil fuels. Moreover, there are more valuable uses for the world’s limited supply of biomass feedstock, the CCC says, including carbon sequestration and hard-to-abate sectors with few alternatives.

Methodology
The figures in the article are from Carbon Brief analysis of data from BEIS Energy Trends chapter 5 and chapter 6, as well as from BM Reports. The figures from BM Reports are for electricity supplied to the grid in Great Britain only and are adjusted to include Northern Ireland.

In Carbon Brief’s analysis, the BM Reports numbers are also adjusted to account for electricity used by power plants on site and for generation by plants not connected to the high-voltage national grid. This includes many onshore windfarms, as well as industrial gas combined heat and power plants and those burning landfill gas, waste or sewage gas.

By design, the Carbon Brief analysis is intended to align as closely as possible to the official government figures on electricity generated in the UK, reported in BEIS Energy Trends table 5.1.

Briefly, the raw data for each fuel is in most cases adjusted with a multiplier, derived from the ratio between the reported BEIS numbers and unadjusted figures for previous quarters.

Carbon Brief’s method of analysis has been verified against published BEIS figures using “hindcasting”. This shows the estimates for total electricity generation from fossil fuels or renewables to have been within ±3% of the BEIS number in each quarter since Q4 2017. (Data before then is not sufficient to carry out the Carbon Brief analysis.)

For example, in the second quarter of 2019, a Carbon Brief hindcast estimates gas generation at 33.1TWh, whereas the published BEIS figure was 34.0TWh. Similarly, it produces an estimate of 27.4TWh for renewables, against a BEIS figure of 27.1TWh.

National Grid recently shared its own analysis for electricity in Great Britain during 2019 via its energy dashboard, which differs from Carbon Brief’s figures.

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Rising Greenhouse Gas Concentrations drive climate change, with CO2, methane, and nitrous oxide surging; WMO data show higher radiative forcing, elevated pre-industrial baselines, and persistent atmospheric concentrations despite Paris Agreement emissions pledges.

Key Points

Increasing atmospheric CO2, methane, and nitrous oxide levels that raise radiative forcing and drive warming.

✅ WMO data show CO2 at 407.8 ppm in 2018, above decade average

✅ Methane and nitrous oxide surged, elevating total radiative forcing

✅ Concentrations differ from emissions; sinks absorb about half

The World Meteorological Organization (WMO) says the increase in CO2 was just above the average rise recorded over the last decade.

Levels of other warming gases, such as methane and nitrous oxide, have also surged by above average amounts.

Since 1990 there's been an increase of 43% in the warming effect on the climate of long lived greenhouse gases.

The WMO report looks at concentrations of warming gases in the atmosphere rather than just emissions.

The difference between the two is that emissions refer to the amount of gases that go up into the atmosphere from the use of fossil fuels, such as burning coal for coal-fired electricity generation and from deforestation.

Concentrations are what's left in the air after a complex series of interactions between the atmosphere, the oceans, the forests and the land. About a quarter of all carbon emissions are absorbed by the seas, and a similar amount by land and trees, while technologies like carbon capture are being explored to remove CO2.

Using data from monitoring stations in the Arctic and all over the world, researchers say that in 2018 concentrations of CO2 reached 407.8 parts per million (ppm), up from 405.5ppm a year previously.

This increase was above the average for the last 10 years and is 147% of the "pre-industrial" level in 1750.

The WMO also records concentrations of other warming gases, including methane and nitrous oxide, and some countries have reported declines in certain potent gases, as noted in US greenhouse gas controls reports, though global levels remain elevated. About 40% of the methane emitted into the air comes from natural sources, such as wetlands, with 60% from human activities, including cattle farming, rice cultivation and landfill dumps.

Methane is now at 259% of the pre-industrial level and the increase seen over the past year was higher than both the previous annual rate and the average over the past 10 years.

Nitrous oxide is emitted from natural and human sources, including from the oceans and from fertiliser-use in farming. According to the WMO, it is now at 123% of the levels that existed in 1750.

Last year's increase in concentrations of the gas, which can also harm the ozone layer, was bigger than the previous 12 months and higher than the average of the past decade.

What concerns scientists is the overall warming impact of all these increasing concentrations. Known as total radiative forcing, this effect has increased by 43% since 1990, and is not showing any indication of stopping.

There is no sign of a slowdown, let alone a decline, in greenhouse gases concentration in the atmosphere despite all the commitments under the Paris agreement on climate change and the ongoing global energy transition efforts," said WMO Secretary-General Petteri Taalas.

"We need to translate the commitments into action and increase the level of ambition for the sake of the future welfare of mankind," he added.

"It is worth recalling that the last time the Earth experienced a comparable concentration of CO2 was three to five million years ago. Back then, the temperature was 2-3C warmer, sea level was 10-20m higher than now," said Mr Taalas.

The UN Environment Programme will report shortly on the gap between what actions countries are taking to cut carbon, for example where Australia's emissions rose 2% recently, and what needs to be done to keep under the temperature targets agreed in the Paris climate pact.

Preliminary findings from this study, published during the UN Secretary General's special climate summit last September, indicated that emissions continued to rise during 2018, although global emissions flatlined in 2019 according to the IEA.

Both reports will help inform delegates from almost 200 countries who will meet in Madrid next week for COP25, following COP24 in Katowice the previous year, the annual round of international climate talks.

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India Thermal Power Coal Imports surged 17.6% as CEA-monitored plants offset weaker CIL and SCCL supplies, driven by Saubhagya-led electricity demand, regional power deficits, and varied consumption across Uttar Pradesh, Bihar, Maharashtra, and Gujarat.

Key Points

Fuel volumes imported for Indian thermal plants, tracked by CEA, reflecting shifts in CIL/SCCL supply, demand, and regional power deficits.

✅ Imports up 17.6% as domestic CIL/SCCL deliveries lag targets

✅ Saubhagya-driven demand lifts generation in key beneficiary states

✅ Industrial slowdowns cut usage in Maharashtra, Tamil Nadu, Gujarat

The receipt of imported coal by thermal power plants, where plant load factors have risen, has shot up by 17.6 per cent during April-October. The coal import volumes refer to the power plants monitored by the Central Electricity Authority (CEA), and come amid moves to ration coal supplies as electricity demand surges, a power update report from CARE Ratings showed.

Imports escalated as domestic supplies by Coal India Ltd (CIL) and another state run producer- Singareni Collieries Company Ltd (SCCL) dipped in the period, after earlier shortages that have since eased in later months. Rate of supplies by the two coal companies to the CEA monitored power stations stood at 80.4 per cent, indicating a shortfall of 19.6 per cent against the allocated quantity.

According to the study by CARE Ratings, total coal supplied by CIL and SCCL to the power sector stood at 315.9 million tonnes (mt) during April-October as against 328.5 mt in the comparable period of last fiscal year.

The study noted that growth in power generation during the April-October 2019, with India now the third-largest electricity producer globally, was on account of higher demand from Pradhan Mantri Sahaj Bijli Har Ghar Yojana or Saubhagya Scheme beneficiary states. Providing connection to households in order to achieve 100% per cent electrification has in part helped the sector avert de-growth, as part of efforts to rewire Indian electricity and expand access.

Large states namely Uttar Pradesh, Bihar, Punjab, West Bengal and Rajasthan have recorded over five per cent growth in consumption of power. These states along with Odisha, Madhya Pradesh and Assam accounted for 75 per cent of the beneficiaries under the Saubhagya Scheme (Household Electrification Scheme). The ongoing economic downturn has led to a sharp fall in electricity demand from industrialised states. Maharashtra, which is also the largest power consuming state in India, recorded a decline in consumption of 5.6 per cent.

Other states namely Tamil Nadu, Telangana, Gujarat and Odisha too recorded fall in power consumed, echoing global dips in daily electricity demand seen later during the pandemic. These states house large clusters of mining, automobile, cement and other manufacturing industries, and a decline in these sectors led to fall in demand for power across these states. - The demand-supply gap or power deficit has remained at 0.6 per cent during the April-October 2019. North-East reported 4.8 per cent of power deficit followed by Northern Region at 1.3 per cent. Within Northern Region, Jammu & Kashmir and Uttar Pradesh accounted for 65 per cent and 30 per cent respectively of the regions power supply deficit.

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