A former manager at one of California's two nuclear power stations sued the facility's operators, claiming he was fired in retaliation for reporting safety concerns at the plant.
The suit against Southern California Edison, principal owner of the San Onofre Nuclear Generating Station, comes a year after the U.S. Nuclear Regulatory Commission rebuked the company for what the government called a "chilling effect" on the airing of safety concerns by employees.
In a March 2010 letter cited in the lawsuit and provided to reporters by lawyers for the plaintiff, Paul Diaz, 35, the NRC ordered Edison to address a workplace climate in which workers feared retribution for reporting safety issues.
According to the lawsuit, the NRC inquiry and letter were prompted by anonymous calls and e-mails from plant "insiders" raising concerns about "shortcuts on testing new generators, unreported safety violations, falsifying records and promoting a culture of cover-up."
The lawsuit also cited problems with chronic fatigue among workers caused by lengthy shifts and heavy overtime demands.
Edison spokesman Gil Alexander said in a written statement that the company had not yet been served with a copy of the lawsuit and does not comment on pending litigation.
"However, we can say that, by policy, SCE considers retaliation against employees who raise safety concerns a termination offense," the statement said.
Diaz filed suit in Los Angeles County Superior Court, seeking unspecified damages. The complaint names Southern California Edison and his former supervisor.
The San Onofre plant sits on the Pacific coast near the border of San Diego and Orange counties, about 60 miles southeast of Los Angeles. The two reactors there went into commercial operation in the 1980s.
The state's only other nuclear power plant in operation is the Diablo Canyon facility, owned by Pacific Gas and Electric Company, near San Luis Obispo on the central California coast.
Diaz was first hired at San Onofre in 1999 as a security officer and later promoted into management, his lawsuit says. He left San Onofre in 2008 to work for a northern California company, then was recruited back to the plant in 2010.
His return preceded the NRC letter by a few months, his attorney, Maria Severin, told Reuters.
"Some employees came to him with issues they were afraid to bring up because they feared retaliation," Severin said. "So he brought them up. They his supervisors told him: don't be a superhero."
Diaz, then manager of business and accounting and project service, was fired in October 2010, his complaint states. The ostensible reason for his dismissal was poor performance, but the lawsuit does not give specifics.
Airport City Solar Edmonton will deliver a 120-megawatt, 627-acre photovoltaic, utility-scale renewable energy project at EIA, creating jobs, attracting foreign investment, and supplying clean power to Fortis Alberta and airport distribution systems.
Key Points
A 120 MW, 627-acre photovoltaic solar farm at EIA supplying clean power to Fortis Alberta and airport systems.
✅ 120 MW utility-scale project over 627 acres at EIA
✅ Feeds Fortis Alberta and airport distribution networks
✅ Drives jobs, investment, and regional sustainability
A European-based company is proposing to build a solar farm bigger than 300 CFL football fields at Edmonton's international airport, aligning with Alberta's red-hot solar growth seen across the province.
Edmonton International Airport and Alpin Sun are working on an agreement that will see the company develop Airport City Solar, a 627-acre, 120-megawatt solar farm that reflects how renewable power developers combine resources for stronger projects on what is now a canola field on the west side of the airport lands.
The solar farm will be the largest at an airport anywhere in the world, EIA said in a news release Tuesday, in a region that also hosts the largest rooftop solar array at a local producer.
"It's a great opportunity to drive economic development as well as be better for the environment," Myron Keehn, vice-president, commercial development and air service at EIA, told CBC News, even as Alberta faces challenges with solar expansion that require careful planning.
"We're really excited that [Alpin Sun] has chosen Edmonton and the airport to do it. It's a great location. We've got lots of land, we're geographically located north, which is great for us, because it allows us to have great hours of sunlight.
"As everyone knows in Edmonton, you can golf early in the morning or golf late at night in the summertime here. And in wintertime it's great, because of the snow, and the reflective [sunlight] off the snow that creates power as well."
Airport official Myron Keehn says the field behind him will become home to the world's largest solar farm at an airport. (Scott Neufeld/CBC)
The project will "create jobs, provide sustainable solar power for our region and show our dedication to sustainability," Tom Ruth, EIA president and CEO, said in the news release, while complementing initiatives by Ermineskin First Nation to expand Indigenous participation in electricity generation.
Construction is expected to begin in early 2022, as new solar facilities in Alberta demonstrate lower costs than natural gas. The solar farm would be operational by the end of that year, the release said.
Alpin Sun says the project will bring in $169 million in foreign investment to the Edmonton metro region amid federal green electricity contracts that are boosting market certainty.
Power generated by Airport City Solar will feed into Fortis Alberta and airport distribution systems.
EV Grid Capacity Management shows how smart charging, load balancing, and off-peak pricing align with utility demand response, DC fast charging networks, and renewable integration to keep national electricity infrastructure reliable as EV adoption scales
Key Points
EV Grid Capacity Management schedules charging and balances load to keep EV demand within utility capacity.
✅ Off-peak pricing and time-of-use tariffs shift charging demand.
✅ Smart chargers enable demand response and local load balancing.
✅ Gradual EV adoption allows utilities to plan upgrades efficiently.
One of the most frequent concerns you will see from electric vehicle haters is that the electricity grid can’t possibly cope with all cars becoming EVs, or that EVs will crash the grid entirely. However, they haven’t done the math properly. The grids in most developed nations will be just fine, so long as the demand is properly management. Here’s how.
The biggest mistake the social media keyboard warriors make is the very strange assumption that all cars could be charging at once. In the UK, there are currently 32,697,408 cars according to the UK Department of Transport. The UK national grid had a capacity of 75.8GW in 2020. If all the cars in the UK were EVs and charging at the same time at 7kW (the typical home charger rate), they would need 229GW – three times the UK grid capacity. If they were all charging at 50kW (a common public DC charger rate), they would need 1.6TW – 21.5 times the UK grid capacity. That sounds unworkable, and this is usually the kind of thinking behind those who claim the UK grid can't cope with EVs.
What they don’t seem to realize is that the chances of every single car charging all at once are infinitesimally low. Their arguments seem to assume that nobody ever drives their car, and just charges it all the time. If you look at averages, the absurdity of this position becomes particularly clear. The distance each UK car travels per year has been slowly dropping, and was 7,400 miles on average in 2019, again according to the UK Department of Transport. An EV will do somewhere between 2.5 and 4.5 miles per kWh on average, so let’s go in the middle and say 3.5 miles. In other words, each car will consume an average of 2,114kWh per year. Multiply that by the number of cars, and you get 69.1TWh. But the UK national grid produced 323TWh of power in 2019, so that is only 21.4% of the energy it produced for the year. Before you argue that’s still a problem, the UK grid produced 402TWh in 2005, which is more than the 2019 figure plus charging all the EVs in the UK put together. The capacity is there, and energy storage can help manage EV-driven peaks as well.
Let’s do the same calculation for the USA, where an EV boom is about to begin and planning matters. In 2020, there were 286.9 million cars registered in America. In 2020, while the US grid had 1,117.5TW of utility electricity capacity and 27.7GW of solar, according to the US Energy Information Administration. If all the cars were EVs charging at 7kW, they would need 2,008.3TW – nearly twice the grid capacity. If they charged at 50kW, they would need 14,345TW – 12.8 times the capacity.
However, in 2020, the US grid generated 4,007TWh of electricity. Americans drive further on average than Brits – 13,500 miles per year, according to the US Department of Transport’s Federal Highway Administration. That means an American car, if it were an EV, would need 3,857kWh per year, assuming the average efficiency figures above. If all US cars were EVs, they would need a total of 1,106.6TWh, which is 27.6% of what the American grid produced in 2020. US electricity consumption hasn’t shrunk in the same way since 2005 as it has in the UK, but it is clearly not unfeasible for all American cars to be EVs. The US grid could cope too, even as state power grids face challenges during the transition.
After all, the transition to electric isn’t going to happen overnight. The sales of EVs are growing fast, with for example more plug-ins sold in the UK in 2021 so far than the whole of the previous decade (2010-19) put together. Battery-electric vehicles are closing in on 10% of the market in the UK, and they were already 77.5% of new cars sold in Norway in September 2021. But that is new cars, leaving the vast majority of cars on the road fossil fuel powered. A gradual introduction is essential, too, because an overnight switchover would require a massive ramp up in charge point installation, particularly devices for people who don’t have the luxury of home charging. This will require considerable investment, but could be served by lots of chargers on street lamps, which allegedly only cost £1,000 ($1,300) each to install, usually with no need for extra wiring.
This would be a perfectly viable way to provide charging for most people. For example, as I write this article, my own EV is attached to a lamppost down the street from my house. It is receiving 5.5kW costing 24p (32 cents) per kWh through SimpleSocket, a service run by Ubitricity (now owned by Shell) and installed by my local London council, Barnet. I plugged in at 11am and by 7.30pm, my car (which was on about 28% when I started) will have around 275 miles of range – enough for a couple more weeks. It will have cost me around £12 ($16) – way less than a tank of fossil fuel. It was a super-easy process involving the scanning of a QR code and entering of a credit card, very similar to many parking systems nowadays. If most lampposts had one of these charging plugs, not having off-street parking would be no problem at all for owning an EV.
With most EVs having a range of at least 200 miles these days, and the average mileage per day being 20 miles in the UK (the 7,400-mile annual figure divided by 365 days) or 37 miles in the USA, EVs won’t need charging more than once a week or even every week or two. On average, therefore, the grids in most developed nations will be fine. The important consideration is to balance the load, because if too many EVs are charging at once, there could be a problem, and some regions like California are looking to EVs for grid stability as part of the solution. This will be a matter of incentivizing charging during off-peak times such as at night, or making peak charging more expensive. It might also be necessary to have the option to reduce charging power rates locally, while providing the ability to prioritize where necessary – such as emergency services workers. But the problem is one of logistics, not impossibility.
There will be grids around the world that are not in such a good place for an EV revolution, at least not yet, and some critics argue that policies like Canada's 2035 EV mandate are unrealistic. But to argue that widespread EV adoption will be an insurmountable catastrophe for electricity supply in developed nations is just plain wrong. So long as the supply is managed correctly to make use of spare capacity when it’s available as much as possible, the grids will cope just fine.
AWS Renewable Energy Projects deliver new wind power for AWS data centers in Ireland, Sweden, and the US, adding 229 MW and 670,000 MWh annually, supporting 100% renewable targets and global cloud sustainability.
Key Points
AWS projects add wind power in Ireland, Sweden, and the US to supply clean energy for AWS data centers.
✅ 229 MW new wind capacity; 670,000 MWh annual generation
✅ Advances 100% renewable goal for global AWS infrastructure
Amazon has announced three new clean energy projects as part of its long-term goal to power all Amazon Web Services (AWS) global infrastructure with renewable energy. These projects – one in Ireland, one in Sweden, and one in the United States – will deliver wind-generated energy that will total over 229 megawatts (MW) of power, with expected generation of over 670,000 megawatt hours (MWh) of renewable energy annually. The new projects are part of AWS’s long-term commitment to achieve 100 percent renewable energy for its global infrastructure. In 2018, AWS exceeded 50 percent renewable energy for its global infrastructure.
Once complete, these projects, combined with AWS’s previous nine renewable energy projects, reflect how renewable power developers benefit from diversified sources and are expected to generate more than 2,700,000 MWh of renewable energy annually – equivalent to the annual electricity consumption of over 262,000 US homes, which is approximately the size of the city of Nashville, Tennessee.
“Each of these projects brings us closer to our long-term commitment to use 100 percent renewable energy to power our global AWS infrastructure,” said Peter DeSantis, Vice President of Global Infrastructure and Customer Support, Amazon Web Services. “These projects are well-positioned to serve AWS data centers in Ireland, Sweden, and the US. We expect more projects in 2019 as we continue toward our goal of powering all AWS global infrastructure with renewable energy.”
Amazon has committed to buying the energy from a new wind project in Ireland, a 91.2 MW wind farm in Donegal. The Donegal wind farm project is expected to deliver clean energy no later than the end of 2021.
“AWS’s investment in renewable projects in Ireland illustrates their continued commitment to adding clean energy to the grid and it will make a positive contribution to Ireland’s renewable energy goals,” said Leo Varadkar, An Taoiseach of Ireland. “As a significant employer in Ireland, it is very encouraging to see Amazon taking a lead on this issue. We look forward to continuing to work with Amazon as we strive to make Ireland a leader on renewable energy.”
Amazon will also purchase 91 MW of power from a new wind farm in Bäckhammar, Sweden, which is expected to deliver renewable energy by the end of 2020.
“Sweden has long been known for ambitious renewable energy goals, and this new wind farm showcases both our country’s leadership and AWS’s commitment to renewable energy,” said Anders Ygeman, Sweden’s Minister for Energy and Digital Development. “This is a significant step in Sweden’s renewable energy production as we work toward our target of 100 percent renewable energy by 2040.”
California leads the United States in renewable electricity generation from non-hydroelectric sources, as US solar and wind growth accelerates, and the state’s Tehachapi Mountains, where AWS’s wind farm will be located, contain some of the largest wind farms in the country. The wind farm project in Tehachapi is expected to bring up to 47 MW of new renewable energy capacity by the end of 2020.
“This announcement from AWS is great news, not just for California, but for the entire country, as it reaffirms our role as a leader in renewable energy and allows us to take an important step forward on deploying the clean energy we need to respond to climate change,” said California State Senator Jerry Hill, San Mateo and Santa Clara Counties, a member of the Senate Standing Committee on Energy, Utilities and Communications.
Beyond the sustainability initiatives focused on powering the AWS global infrastructure, Amazon recently announced Shipment Zero, which is Amazon’s vision to make all Amazon shipments net zero carbon, with 50 percent of all shipments net zero by 2030. Additional sustainability programs across the company include Amazon Wind Farm Texas, which adds more than 1 million MWh of clean energy each year, alongside Amazon Wind Farm US East that is now fully operational, demonstrating scale. In total, Amazon has enabled 53 wind and solar projects worldwide, which produce more than 1,016 MW and are expected to deliver over 3,075,636 million MWh of energy annually, while peers like Arvato's solar power plant underscore broader momentum across the industry. These projects support hundreds of jobs, while providing tens of millions of dollars of investment in local communities, with Iowa wind power offering a strong example. Amazon has also set a goal to host solar energy systems at 50 fulfillment centers by 2020. This deployment of rooftop solar systems, aided by cheap batteries that enhance storage, is part of a long-term initiative that will start in North America and spread across the globe. Amazon also implemented the District Energy Project that uses recycled energy for heating Amazon offices in Seattle. For more information on Amazon’s sustainability initiatives, visit www.amazon.com/sustainability.
PG&E Bankruptcy Plan outlines wildfire victims compensation via a $13.5B trust funded by cash and stock, aiming CPUC and court approval before June 30 to access the state wildfire insurance fund and finalize settlement.
Key Points
A regulator-approved plan funding a $13.5B wildfire victims trust with cash and PG&E stock to exit bankruptcy.
✅ $13.5B trust split between cash and PG&E shares
✅ Targets CPUC and court approval to meet June 30 deadline
✅ Accesses state wildfire insurance fund for future risks
Pacific Gas & Electric's plan for getting out of bankruptcy has won overwhelming support from the victims of deadly Northern California wildfires ignited by the utility's fraying electrical grid, while some have pursued mega-fire lawsuits through the courts as well, despite concerns that they will be shortchanged by a $13.5 billion fund that's supposed to cover their losses.
The company announced the preliminary results of the vote on Monday without providing a specific tally. Those numbers are supposed to be filed with U.S. Bankruptcy Judge Dennis Montali by Friday.
The backing of the wildfire victims keeps PG&E on track to meet a June 30 deadline to emerge from bankruptcy in time to qualify for a coverage from a California wildfire insurance fund created to help protect the utility from getting into financial trouble again.
The current bankruptcy case, which began early last year, will require PG&E to pay out about $25.5 billion to cover the devastation caused by its neglect, including a Camp Fire guilty plea that underscored liabilities in court proceedings. It's the second time in less than 20 years that PG&E has filed for bankruptcy.
The backing for PG&E's plan isn't a surprise, even though some of the roughly 80,000 wildfire victims had been trying to rally resistance to what they consider to be a deeply flawed plan. The misgivings mostly center on the massive debt that the utility will take on to finance the plan and uncertainties about the fluctuating value of the $6.75 billion in company stock that comprises half of the $13.5 billion promised them.
As it became apparent that the COVID-19 pandemic would drive the economy into a deep recession, PG&E's shares plunged along with the rest of the stock market during March, even as it announced pandemic response measures for customers and employees during that period. That led one financial expert to estimate the PG&E stock earmarked for the wildfire victims' trust would be worth only $4.85 billion, a nearly 30% markdown.
But PG&E's stock price has rebounded in recent weeks and it's now worth more than it was when the deal setting up the victims' trust was struck last December. The shares surged more than 8% to $12.28 in Monday's late afternoon trading. The stock stood at $9.65 when PG&E reached its settlement the wildfire victims.
Critics of the utility's plan also are upset because the company still hasn't specified when the fire victims will be able to sell the shares. It now seems likely the victims will have to hold the stock through the upcoming wildfire season in Northern California, raising the specter that another calamity caused by the utility's badly outdated equipment, as power line fire reports have underscored, could cause the shares to plummet before they can cash out.
A petition signed by more than 3,100 wildfire victims recently urged Gov. Gavin Newsom to consider pushing back the deadline for qualifying for the state's wildfire from June 30 to late August to allow for more time to revise PG&E's plan, as many also turn to a wildfire assistance program for interim aid while they wait. Newsom's office hasn't responded to inquiry about the plan from The Associated Press.
But the lawyers representing the wildfire victims advised their clients to vote in favor of PG&E's plan, contending that it's the best deal they are going to get.
PG&E still must get its plan approved by the judge supervising its case, and a recent judge order on dividend use underscores the focus on wildfire mitigation. The confirmation hearings are scheduled to begin May 27. The judge, though, has indicated he will give great weight to the wishes of the wildfire victims.
California state regulators also must approve PG&E's plan, amid projections that rates will stabilize in 2025 for customers. A vote on that is scheduled Thursday before the Public Utilities Commission.
Transcranial electrical stimulation synchronizes brain waves to bolster working memory, aligning neural oscillations across the prefrontal and temporal cortex. This noninvasive brain stimulation may counter cognitive aging by restoring network coupling and improving short-term recall.
Key Points
Transcranial electrical stimulation applies scalp currents to synchronize brain waves, briefly enhancing working memory.
✅ Synchronizes prefrontal-temporal networks to restore coupling
✅ Noninvasive tES/tACS protocols show rapid, reversible gains
✅ Effects lasted under an hour; durability remains to be tested
To read this sentence, you hold the words in your mind for a few seconds until you reach the period. As you do, neurons in your brain fire in coordinated bursts, generating electrical waves that let you hold information for as long as it is needed, much as novel devices can generate electricity from falling snow under specific conditions. But as we age, these brain waves start to get out of sync, causing short-term memory to falter. A new study finds that jolting specific brain areas with a periodic burst of electricity might reverse the deficit—temporarily, at least.
The work makes “a strong case” for the idea that out-of-sync brain waves in specific regions can drive cognitive aging, says Vincent Clark, a neuroscientist at the University of New Mexico in Albuquerque, who was not involved in the research. He adds that the brain stimulation approach in the study may result in a new electrical therapy for age-related deficits in working memory.
Working memory is “the sketchpad of the mind,” allowing us to hold information in our minds over a period of seconds. This short-term memory is critical to accomplishing everyday tasks such as planning and counting, says Robert Reinhart, a neuroscientist at Boston University who led the study. Scientists think that when we use this type of memory, millions of neurons in different brain areas communicate through coupled bursts of activity, a form of electrical conduction that coordinates timing across networks. “Cells that fire together, wire together,” Reinhart says.
But despite its critical role, working memory is a fragile cognitive resource that declines with age, Reinhart says. Previous studies had suggested that reduced working-memory performance in the elderly is linked to uncoupled activity in different brain areas. So Reinhart and his team set out to test whether recoupling brain waves in older adults could boost the brain’s ability to temporarily store information, a systems-level coordination challenge akin to efforts to use AI for energy savings on modern power grids.
To do so, the researchers used jolts of weak electrical current to synchronize waves in the prefrontal and temporal cortex—two brain areas critical for cognition, a targeted approach not unlike how grids use batteries to stabilize power during strain—and applied the current to the scalps of 42 healthy people in their 60s and 70s who showed no signs of decline in mental ability. Before their brains were zapped, participants looked at a series of images: an everyday object, followed briefly by a blank screen, and then either an identical or a modified version of the same object. The goal was to spot whether the two images were different.
Then the participants took the test again, while their brains were stimulated with a current. After about 25 minutes of applying electricity, participants were on average more accurate at identifying changes in the images than they were before the stimulation. Following stimulation, their performance in the test was indistinguishable from that of a group of 42 people in their 20s. And the waves in the prefrontal and temporal cortex, which had previously been out of sync in most of the participants, started to fire in sync, the researchers report today in Nature Neuroscience, a synchronization imperative reminiscent of safeguards that prevent power blackouts on threatened grids. No such effects occurred in a second group of older people who received jolts of current that didn’t synchronize waves in the prefrontal and temporal cortex.
By using bursts of current to knock brain waves out of sync, the researchers also modulated the brain chatter in healthy people in their 20s, making them slower and less accurate at spotting differences in the image test.
“This is a very nice and clear demonstration of how functional connections underlie memory in younger adults and how alterations … can lead to memory reductions in older adults,” says Cheryl Grady, a cognitive neuroscientist at the Rotman Research Institute at Baycrest in Toronto, Canada. It’s also the first time that transcranial stimulation has been shown to restore working memory in older people, says Michael O’Sullivan, a neuroscientist at the University of Queensland in Brisbane, Australia, though electricity in medicine extends far beyond neurostimulation.
But whether brain zapping could turbocharge the cognitive abilities of seniors or help improve the memories of people with diseases like Alzheimer’s is still unclear: In the study, the positive effects on working memory lasted for just under an hour—though Reinhart says that’s as far as they recorded in the experiment. The team didn’t see the improvements decline toward the end, so he suspects that the cognitive boost may last for longer. Still, researchers say much more work has to be done to better understand how the stimulation works.
Clark is optimistic. “No pill yet developed can produce these sorts of effects safely and reliably,” he says. “Helping people is the ultimate goal of all of our research, and it’s encouraging to see that progress is being made.”
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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