India identifies potential sites for nuclear power plants

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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London Underground Power Outage 2025 disrupted Tube lines citywide, with a National Grid voltage dip causing service suspensions, delays, and station closures; TfL recovery efforts spotlight infrastructure resilience, contingency planning, and commuter safety communications.

Key Points

A citywide Tube disruption on May 12, 2025, triggered by a National Grid voltage dip, exposing resilience gaps.

✅ Bakerloo, Waterloo & City, Northern suspended; Jubilee disrupted.

✅ Cause: brief National Grid fault leading to a voltage dip.

✅ TfL focuses on recovery, communication, and resilience upgrades.

On May 12, 2025, a significant power outage disrupted the London Underground during the afternoon rush hour, affecting thousands of commuters across the city. The incident highlighted vulnerabilities in the city's transport infrastructure, echoing a morning outage in London reported earlier, and raised concerns about the resilience of urban utilities.

The Outage and Its Immediate Impact

The power failure occurred around 2:30 PM, leading to widespread service suspensions and delays on several key Tube lines. The Bakerloo and Waterloo & City lines were completely halted, while the Jubilee line experienced disruptions between London Bridge and Finchley Road. The Northern line was also suspended between Euston and Kennington, as well as south of Stockwell. Additionally, Elizabeth Line services between Abbey Wood and Paddington were suspended. Some stations were closed for safety reasons due to the lack of power.

Commuters faced severe delays, with many stranded in tunnels or on platforms. The lack of information and communication added to the confusion, as passengers were left uncertain about the cause and duration of the disruptions.

Cause of the Power Failure

Transport for London (TfL) attributed the outage to a brief fault in the National Grid's transmission network. Although the fault was resolved within seconds, it caused a voltage dip that affected local distribution networks, leading to the power loss in the Underground system.

The incident underscored the fragility of the city's transport infrastructure, particularly the aging electrical and signaling systems that are vulnerable to such faults, as well as weather-driven events like a major windstorm outage that can trigger cascading failures. While backup systems exist, their capacity to handle sudden disruptions remains a concern.

Broader Implications for Urban Infrastructure

This power outage is part of a broader pattern of infrastructure challenges facing London. In March 2025, a fire at an electrical substation in Hayes led to the closure of Heathrow Airport, affecting over 200,000 passengers, while similar disruptions at BWI Airport have underscored aviation vulnerabilities. These incidents have prompted discussions about the resilience of the UK's energy and transport networks.

Experts argue that aging infrastructure, coupled with increasing demand and climate-related stresses, poses significant risks to urban operations, as seen in a North Seattle outage and in Toronto storm-related outages that tested local grids. There is a growing call for investment in modernization and diversification of energy sources to ensure reliability and sustainability.

TfL's Response and Recovery Efforts

Following the outage, TfL worked swiftly to restore services. By 11 PM, all but one line had resumed operations, with only the Elizabeth Line continuing to experience severe delays. TfL officials acknowledged the inconvenience caused to passengers and pledged to investigate the incident thoroughly, similar to the Atlanta airport blackout inquiry conducted after a major outage, to prevent future occurrences.

In the aftermath, TfL emphasized the importance of clear communication with passengers during disruptions and committed to enhancing its contingency planning and infrastructure resilience.

Public Reaction and Ongoing Concerns

The power outage sparked frustration among commuters, many of whom took to social media to express their dissatisfaction, echoing sentiments during Houston's extended outage about communication gaps and delays. Some passengers reported being trapped in tunnels for extended periods without clear guidance from staff.

The incident has reignited debates about the adequacy of London's transport infrastructure and the need for comprehensive upgrades. While TfL has initiated reviews and improvement plans, the public remains concerned about the potential for future disruptions and the city's preparedness to handle them.

The May 12 power outage serves as a stark reminder of the vulnerabilities inherent in urban infrastructure. As London continues to grow and modernize, ensuring the resilience of its transport and energy networks will be crucial. This includes investing in modern technologies, enhancing communication systems, and developing robust contingency plans to mitigate the impact of future disruptions. For now, Londoners are left reflecting on the lessons learned from this incident and hoping for a more reliable and resilient transport system in the future.

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Existing Nuclear Reactor Lifetime Extension sustains carbon-free electricity, supports deep decarbonization, and advances net zero climate goals by preserving the US nuclear fleet, stabilizing the grid, and complementing advanced reactors.

Key Points

Extending licenses keeps carbon-free nuclear online, stabilizes grid, and accelerates decarbonization toward net zero.

✅ Preserves 24/7 carbon-free baseload to meet climate targets

✅ Avoids emissions and replacement costs from premature retirements

✅ Complements advanced reactors; reduces capital and material needs

Nuclear power is the single largest source of carbon-free energy in the United States and currently provides nearly 20 percent of the nation’s electrical demand. As a result, many analyses have investigated the potential of future nuclear energy contributions in addressing climate change and investing in carbon-free electricity across the sector. However, few assess the value of existing nuclear power reactors.

Research led by Pacific Northwest National Laboratory (PNNL) Earth scientist Son H. Kim, with the Joint Global Change Research Institute (JGCRI), a partnership between PNNL and the University of Maryland, has added insight to the scarce literature and is the first to evaluate nuclear energy for meeting deep decarbonization goals amid rising credit risks for nuclear power identified by Moody's. Kim sought to answer the question: How much do our existing nuclear reactors contribute to the mission of meeting the country’s climate goals, both now and if their operating licenses were extended?

As the world races to discover solutions for reaching net zero as part of the global energy transition now underway, Kim’s report quantifies the economic value of bringing the existing nuclear fleet into the year 2100. It outlines its significant contributions to limiting global warming.

Plants slated to close by 2050 could be among the most important players in a challenge requiring all available carbon-free technology solutions—emerging and existing—alongside renewable electricity in many regions, the report finds. New nuclear technology also has a part to play, and its contributions could be boosted by driving down construction costs.  

“Even modest reductions in capital costs could bring big climate benefits,” said Kim. “Significant effort has been incorporated into the design of advanced reactors to reduce the use of all materials in general, such as concrete and steel because that directly translates into reduced costs and carbon emissions.”

Nuclear power reactors face an uncertain future, and some utilities face investor pressure to release climate reports as well.
The nuclear power fleet in the United States consists of 93 operating reactors across 28 states. Most of these plants were constructed and deployed between 1970-1990. Half of the fleet has outlived its original operating license lifetime of 40 years. While most reactors have had their licenses renewed for an additional 20 years, and some for another 20, the total number of reactors that will receive a lifetime extension to operate a full 80 years from deployment is uncertain.

Other countries also rely on nuclear energy. In France, for example, nuclear energy provides 70 percent of the country’s power supply. They and other countries must also consider extending the lifetime, retiring, or building new, modern reactors while navigating Canadian climate policy implications for electricity grids. However, the U.S. faces the potential retirement of many reactors in a short period—this could have a far stronger impact than the staggered closures other countries may experience.

“Our existing nuclear power plants are aging, and with their current 60-year lifetimes, nearly all of them will be gone by 2050. It’s ironic. We have a net zero goal to reach by 2050, yet our single largest source of carbon-free electricity is at risk of closure, as seen in New Zealand's electricity transition debates,“ said Kim.

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New Zealand Renewable Energy Strategy examines decarbonisation, GHG emissions, and net energy as electrification accelerates, expanding hydro, geothermal, wind, and solar PV while weighing intermittency, storage, materials, and energy security for a resilient power system.

Key Points

A plan to expand electricity generation, balancing decarbonisation, net energy limits, and energy security.

✅ Distinguishes decarbonisation targets from renewable capacity growth

✅ Highlights net energy limits, intermittency, and storage needs

✅ Addresses materials, GHG build-out costs, and energy security

The Electricity Authority has released a document outlining a plan to achieve the Government’s goal of more than doubling the amount of electricity generated in New Zealand over the next few decades.

This goal is seen as a way of both reducing our greenhouse gas (GHG) emissions overall, as everything becomes electrified, and ensuring we have a 100 percent renewable energy system at our disposal. Often these two goals are seen as being the same – to decarbonise we must transition to more renewable energy to power our society.

But they are quite different goals and should be clearly differentiated. GHG emissions could be controlled very effectively by rationing the use of a fossil fuel lockdown approach, with declining rations being available over a few years. Such a direct method of controlling emissions would ensure we do our bit to remain within a safe carbon budget.

If we took this dramatic step we could stop fretting about how to reduce emissions (that would be guaranteed by the rationing), and instead focus on how to adapt our lives to the absence of fossil fuels.

Again, these may seem like the same task, but they are not. Decarbonising is generally thought of in terms of replacing fossil fuels with some other energy source, signalling that a green recovery must address more than just wind capacity. Adapting our lives to the absence of fossil fuels pushes us to ask more fundamental questions about how much energy we actually need, what we need energy for, and the impact of that energy on our environment.

MBIE data indicate that between 1990 and 2020, New Zealand almost doubled the total amount of energy it produced from renewable energy sources - hydro, geothermal and some solar PV and wind turbines.

Over this same time period our GHG emissions increased by about 25 percent. The increase in renewables didn’t result in less GHG emissions because we increased our total energy use by almost 50 percent, mostly by using fossil fuels. The largest fossil fuel increases were used in transport, agriculture, forestry and fisheries (approximately 60 percent increases for each).

These data clearly demonstrate that increasing renewable energy sources do not necessarily result in reduced GHG emissions.

The same MBIE data indicate that over this same time period, the amount of Losses and Own Use category for energy use more than doubled. As of 2020 almost 30 percent of all energy consumed in New Zealand fell into this category.

These data indicate that more renewable energy sources are historically associated with less energy actually being available to do work in society.

While the category Losses and Own Use is not a net energy analysis, the large increase in this category makes the call for a system-wide net energy analysis all the more urgent.

Net energy is the amount of energy available after the energy inputs to produce and deliver the energy is subtracted. There is considerable data available indicating that solar PV and wind turbines have a much lower net energy surplus than fossil fuels.

And there is further evidence that when the intermittency and storage requirements are engineered into a total renewable energy system, the net energy of the entire system declines sharply. Could the Losses and Other Uses increase over this 30-year period be an indication of things to come?

Despite the importance of net energy analysis in designing a national energy system which is intended to provide energy security and resilience, there is not a single mention of net energy surplus in the EA reference document.

So over the last 30 years, New Zealand has doubled its renewable energy capacity, and at the same time increased its GHG emissions and reduced the overall efficiency of the national energy system.

And we are now planning to more than double our renewable energy system yet again over the next 30 years, even as zero-emissions electricity by 2035 is being debated elsewhere. We need to ask if this is a good idea.

How can we expand New Zealand’s solar PV and wind turbines without using fossil fuels? We can’t.

How could we expand our solar PV and wind turbines without mining rare minerals and the hidden costs of clean energy they entail, further contributing to ecological destruction and often increasing social injustices? We can't.

Even if we could construct, deliver, install and maintain solar PV and wind turbines without generating more GHG emissions and destroying ecosystems and poor communities, this “renewable” infrastructure would have to be replaced in a few decades. But there are at least two major problems with this assumed scenario.

The rare earth minerals required for this replacement will already be exhausted by the initial build out. Recycling will only provide a limited amount of replacements.

The other challenge is that a mostly “renewable” energy system will likely have a considerably lower net energy surplus. So where, in 2060, will the energy come from to either mine or recycle the raw materials, and to rebuild, reinstall and maintain the next iteration of a renewable energy system?

There is currently no plan for this replacement. It is a serious misnomer to call these energy technologies “renewable”. They are not as they rely on considerable raw material inputs and fossil energy for their production and never ending replacement.

New Zealand is, of course, blessed with an unusually high level of hydro electric and geothermal power. New Zealand currently uses over 170 GJ of total energy per capita, 40 percent of which is “renewable”. This provides approximately 70 GJ of “renewable” energy per capita with our current population.

This is the average global per capita energy level from all sources across all nations, as calls for 100% renewable energy globally emphasize. Several nations operate with roughly this amount of total energy per capita that New Zealand can generate just from “renewables”.

It is worth reflecting on the 170 GJ of total energy use we currently consume. Different studies give very different results regarding what levels are necessary for a good life.

For a complex industrial society such as ours, 100 GJ pc is said to be necessary for a high levels of wellbeing, determined both subjectively (life satisfaction/ happiness measures), and objectively (e.g. infant mortality levels, female morbidity as an index of population health, access to nutritious food and educational and health resources, etc). These studies do not take into account the large amount of energy that is wasted either through inefficient technologies, or frivolous use, which effective decarbonization strategies seek to reduce.

Other studies that consider the minimal energy needed for wellbeing suggest a much lower level of per capita energy consumption is required. These studies take a different approach and focus on ensuring basic wellbeing is maintained, but not necessarily with all the trappings of a complex industrial society. Their results indicate a level of approximately 20 GJ per capita is adequate.

In either case, we in New Zealand are wasting a lot of energy, both in terms of the efficiency of our technologies (see the Losses and Own Use info above), and also in our uses which do not contribute to wellbeing (think of the private vehicle travel that could be done by active or public transport – if we had good infrastructure in place).

We in New Zealand need a national dialogue about our future. And energy availability is only one aspect. We need to discuss what our carrying capacity is, what level of consumption is sustainable for our population, and whether we wish to make adjustments in either our per capita consumption or our population. Both together determine whether we are on the sustainable side of carrying capacity. Currently we are on the unsustainable side, meaning our way of life cannot endure. Not a good look for being a good ancestor.

The current trajectory of the Government and Electricity Authority appears to be grossly unsustainable. At the very least they should be able to answer the questions posed here about the GHG emissions from implementing a totally renewable energy system, the net energy of such a system, and the related environmental and social consequences.

Public dialogue is critical to collectively working out our future. Allowing the current profit-driven trajectory to unfold is a recipe for disasters for our children and grandchildren.

Being silent on these issues amounts to complicity in allowing short-term financial interests and an addiction to convenience jeopardise a genuinely secure and resilient future. Let’s get some answers from the Government and Electricity Authority to critical questions about energy security.

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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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Ontario Nuclear Power Costs highlight LCOE, capex, refurbishment outlays, and waste management, compared with renewables, grid reliability, and emissions targets, informing Australia and Peter Dutton on feasibility, timelines, and electricity prices.

Key Points

They include high capex and LCOE from refurbishments and waste, offset by reliable, low-emission baseload.

✅ Refurbishment and maintenance drive lifecycle and LCOE variability.

✅ High capex and long timelines affect consumer electricity prices.

✅ Low emissions, but waste and safety compliance add costs.

Australian opposition leader Peter Dutton recently lauded Canada’s use of nuclear power as a model for Australia’s energy future. His praise comes as part of a broader push to incorporate nuclear energy into Australia’s energy strategy, which he argues could help address the country's energy needs and climate goals. However, the question arises: Is Ontario’s experience with nuclear power as cost-effective as Dutton suggests?

Dutton’s endorsement of Canada’s nuclear power strategy highlights a belief that nuclear energy could provide a stable, low-emission alternative to fossil fuels. He has pointed to Ontario’s substantial reliance on nuclear power, and the province’s exploration of new large-scale nuclear projects, as an example of how such an energy mix might benefit Australia. The province’s energy grid, which integrates a significant amount of nuclear power, is often cited as evidence that nuclear energy can be a viable component of a diversified energy portfolio.

The appeal of nuclear power lies in its ability to generate large amounts of electricity with minimal greenhouse gas emissions. This characteristic aligns with Australia’s climate goals, which emphasize reducing carbon emissions to combat climate change. Dutton’s advocacy for nuclear energy is based on the premise that it can offer a reliable and low-emission option compared to the fluctuating availability of renewable sources like wind and solar.

However, while Dutton’s enthusiasm for the Canadian model reflects its perceived successes, including recent concerns about Ontario’s grid getting dirtier amid supply changes, a closer look at Ontario’s nuclear energy costs raises questions about the financial feasibility of adopting a similar strategy in Australia. Despite the benefits of low emissions, the economic aspects of nuclear power remain complex and multifaceted.

In Ontario, the cost of nuclear power has been a topic of considerable debate. While the province benefits from a stable supply of electricity due to its nuclear plants, studies warn of a growing electricity supply gap in coming years. Ontario’s experience reveals that nuclear power involves significant capital expenditures, including the costs of building reactors, maintaining infrastructure, and ensuring safety standards. These expenses can be substantial and often translate into higher electricity prices for consumers.

The cost of maintaining existing nuclear reactors in Ontario has been a particular concern. Many of these reactors are aging and require costly upgrades and maintenance to continue operating safely and efficiently. These expenses can add to the overall cost of nuclear power, impacting the affordability of electricity for consumers.

Moreover, the development of new nuclear projects, as seen with Bruce C project exploration in Ontario, involves lengthy and expensive construction processes. Building new reactors can take over a decade and requires significant investment. The high initial costs associated with these projects can be a barrier to their economic viability, especially when compared to the rapidly decreasing costs of renewable energy technologies.

In contrast, the cost of renewable energy has been falling steadily, even as debates over nuclear power’s trajectory in Europe continue, making it a more attractive option for many jurisdictions. Solar and wind power, while variable and dependent on weather conditions, have seen dramatic reductions in installation and operational costs. These lower costs can make renewables more competitive compared to nuclear energy, particularly when considering the long-term financial implications.

Dutton’s praise for Ontario’s nuclear power model also overlooks some of the environmental and logistical challenges associated with nuclear energy. While nuclear power generates low emissions during operation, it produces radioactive waste that requires long-term storage solutions. The management of nuclear waste poses significant environmental and safety concerns, as well as additional costs for safe storage and disposal.

Additionally, the potential risks associated with nuclear power, including the possibility of accidents, contribute to the complexity of its adoption. The safety and environmental regulations surrounding nuclear energy are stringent and require continuous oversight, adding to the overall cost of maintaining nuclear facilities.

As Australia contemplates integrating nuclear power into its energy mix, it is crucial to weigh these financial and environmental considerations. While the Canadian model provides valuable insights, the unique context of Australia’s energy landscape, including its existing infrastructure, energy needs, and the costs of scrapping coal-fired electricity in comparable jurisdictions, must be taken into account.

In summary, while Peter Dutton’s endorsement of Canada’s nuclear power model reflects a belief in its potential benefits for Australia’s energy strategy, the cost-effectiveness of Ontario’s nuclear power experience is more nuanced than it may appear. The high capital and maintenance costs associated with nuclear energy, combined with the challenges of managing radioactive waste and ensuring safety, present significant considerations. As Australia evaluates its energy future, a comprehensive analysis of both the benefits and drawbacks of nuclear power will be essential to making informed decisions about its role in the country’s energy strategy.

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