Wal-Mart Canada stores across the country began reducing lighting by one-third for the summer in 240 of its stores, a strategy aimed at helping the company meet its plan to lower carbon emissions by at least 19,000 tons this year. As a result, Wal-Mart Canada expects to slash carbon emissions by over 4,500 tons, help control summer smog conditions, and aid the stability of provincial power grids.
Other energy conservation programs adopted by the company include the ongoing retrofit of stores with more efficient lighting, heating, air conditioning and ventilation systems, and an alternative energy plan that is expected to make the retailer Canada's single largest commercial buyer of alternative energy.
The reduced summer-lighting program was piloted in Wal-Mart stores across Ontario in the summers during 2005 and 2006, originally implemented in response to continuing summer energy concerns in the province. The Canada-wide expansion of the program is a result of the company's sustainability goals and its recently introduced "For the Greener Good" program.
Participating locations have posted door-front notices explaining the change and its environmental benefit to shoppers.
"Our customers have told us to be creative and to act boldly when it comes to sustainability," said Wal-Mart Canada Corp. President and CEO Mario Pilozzi in a statement. "We have been amazed at the positive response and the positive results already."
Wal-Mart Canada now has 13 internal networks looking into opportunities to effect sustainable change in such areas as product availability, shipping, packaging, materials, store construction and design, and greenhouse gas reduction.
"We have found that there is a great marriage between environmental sustainability and business sustainability," said Pilozzi. "There are many ways we can benefit our environment while benefiting our business. The effect of our lighting reductions is a great example: less lighting means we save more than a million dollars in energy costs while also taking the equivalent of 500 cars off the road for the year."
Wal-Mart's three long-term sustainability goals worldwide and in Canada are to produce zero waste, to be powered 100 percent by renewable energy, and to make more environmentally preferable products available to shopper.
Wal-Mart Canada operates 277 discount stores, seven Wal-Mart Supercentres, and six Sam's Club membership warehouse operations.
US Nuclear Generating Costs 2017 show USD33.50/MWh for nuclear energy, the lowest since 2008, as capital expenditures, fuel costs, and operating costs declined after license renewals and uprates, supporting a reliable, low-carbon grid.
Key Points
The 2017 US nuclear average was USD33.50/MWh, lowest since 2008, driven by reduced capital, fuel, and operating costs.
✅ Average cost USD33.50/MWh, lowest since 2008
✅ Capital, fuel, O&M costs fell sharply since 2012 peak
Average total generating costs for nuclear energy in 2017 in the USA were at their lowest since 2008, according to a study released by the Nuclear Energy Institute (NEI), amid a continuing nuclear decline debate in other regions.
The report, Nuclear Costs in Context, found that in 2017 the average total generating cost - which includes capital, fuel and operating costs - for nuclear energy was USD33.50 per megawatt-hour (MWh), even as interest in next-generation nuclear designs grows among stakeholders. This is 3.3% lower than in 2016 and more than 19% below 2012's peak. The reduction in costs since 2012 is due to a 40.8% reduction in capital expenditures, a 17.2% reduction in fuel costs and an 8.7% reduction in operating costs, the organisation said.
The year-on-year decline in capital costs over the past five years reflects the completion by most plants of efforts to prepare for operation beyond their initial 40-year licence. A few major items - a series of vessel head replacements; steam generator replacements and other upgrades as companies prepared for continued operation, and power uprates to increase output from existing plants - caused capital investment to increase to a peak in 2012. "As a result of these investments, 86 of the [USA's] 99 operating reactors in 2017 have received 20-year licence renewals and 92 of the operating reactors have been approved for uprates that have added over 7900 megawatts of electricity capacity. Capital spending on uprates and items necessary for operation beyond 40 years has moderated as most plants are completing these efforts," it says.
Since 2013, seven US nuclear reactors have shut down permanently, with the Three Mile Island debate highlighting wider policy questions, and another 12 have announced their permanent shutdown. The early closure for economic reasons of reliable nuclear plants with high capacity factors and relatively low generating costs will have long-term economic consequences, the report warns: replacement generating capacity, when needed, will produce more costly electricity, fewer jobs that will pay less, and, for net-zero emissions objectives, more pollution, it says.
NEI Vice President of Policy Development and Public Affairs John Kotek said the "hardworking men and women of the nuclear industry" had done an "amazing job" reducing costs through the institute's Delivering the Nuclear Promise campaign and other initiatives, in line with IAEA low-carbon lessons from the pandemic. "As we continue to face economic headwinds in markets which do not properly compensate nuclear plants, the industry has been doing its part to reduce costs to remain competitive," he said.
"Some things are in urgent need of change if we are to keep the nation's nuclear plants running and enjoy their contribution to a reliable, resilient and low-carbon grid. Namely, we need to put in place market reforms that fairly compensate nuclear similar to those already in place in New York, Illinois and other states," Kotek added.
Cost information in the study was collected by the Electric Utility Cost Group with prior years converted to 2017 dollars for accurate historical comparison.
Barakah Unit 4 Cold Hydrostatic Testing validates reactor coolant system integrity at the Barakah Nuclear Energy Plant in Abu Dhabi, UAE, confirming safety, quality, and commissioning readiness under ENEC and KEPCO oversight.
Key Points
Pressure test of Unit 4's reactor coolant system, confirming integrity and safety for commissioning at Barakah.
✅ 25% above normal operating pressure verified.
✅ Welds, joints, and high-pressure components inspected.
The Emirates Nuclear Energy Corporation (ENEC) has successfully completed Cold Hydrostatic Testing (CHT) at Unit 4 of the Barakah Nuclear Energy Plant, the Arab world’s first nuclear energy plant being built in the Al Dhafra region of Abu Dhabi, UAE. The testing incorporated the lessons learned from the previous three units and is a crucial step towards the completion of Unit 4, the final unit of the Barakah plant.
As a part of CHT, the pressure inside Unit 4’s systems was increased to 25 per cent above what will be the normal operating pressure, demonstrating, as seen across global nuclear projects, the quality and robust nature of the Unit’s construction. Prior to the commencement of CHT, Unit 4’s Nuclear Steam Supply Systems were flushed with demineralised water, and the Reactor Pressure Vessel Head and Reactor Coolant Pump Seals were installed. During the Cold Hydrostatic Testing, the welds, joints, pipes and components of the reactor coolant system and associated high-pressure systems were verified.
Mohammed Al Hammadi, Chief Executive Officer of ENEC said: “I am proud of the continued progress being made at Barakah despite the circumstances we have all faced in relation to COVID-19. The UAE leadership’s decisive and proactive response to the pandemic supported us in taking timely, safety-led actions to protect the health and safety of our workforce and our plant. These actions, alongside the efforts of our talented and dedicated workforce, have enabled the successful completion of CHT at Unit 4, which was completed in adherence to the highest standards of safety, quality, and security.
“With this accomplishment, we move another step closer to achieving our goal of supplying up to a quarter of our nation’s electricity needs through the national grid and powering its future growth with safe, reliable, and emissions-free electricity,” he added.
By the end of 2019, ENEC and Korea Electric Power Corporation (KEPCO), working with Korea Hydro & Nuclear Power (KHNP) on the project, had successfully completed all major construction work including major concrete pouring, installation of the Turbine Generator, and the internal components of the Reactor Pressure Vessel (RPV) of Unit 4, which paved the way for the commencement of testing and commissioning.
The testing at Unit 4 represents a significant achievement in the development of the UAE Peaceful Nuclear Energy Program, following the successful completion of fuel assembly loading into Unit 1 in March 2020, confirming that the UAE has officially become a peaceful nuclear energy operating nation. Preparations are now in the final stages for the safe start-up of Unit 1, which subsequently reached 100% power ahead of commercial operations, in the coming months.
ENEC is currently in the final stages of construction of units 2, 3 and 4 of the Barakah Nuclear Energy Plant, as China’s nuclear program continues its steady development globally. The overall construction of the four units is more than 94% complete. Unit 4 is more than 84 per cent, Unit 3 is more than 92 per cent and Unit 2 is more than 95 per cent. The four units at Barakah will generate up to 25 per cent of the UAE’s electricity demand by producing 5,600 MW of clean baseload electricity, as projects such as new reactors in Georgia take shape, and preventing the release of 21 million tons of carbon emissions each year – the equivalent of removing 3.2 million cars off the roads annually.
Hydrogen Energy Transition accelerates green hydrogen, electrolyzers, renewables, and fuel cells, as the EU and US scale decarbonization, NextEra tests hydrogen-to-power, and DOE funds pilots to replace natural gas and cut CO2.
Key Points
A shift to deploy green hydrogen tech to decarbonize power, industry, and transport across EU and US energy systems.
✅ EU targets 40 GW electrolyzers plus 40 GW imports by 2030
✅ DOE funds pilots; NextEra trials hydrogen-to-power at Okeechobee
✅ Aims to replace natural gas, enable fuel cells, cut CO2
Last month, the European Union set out a comprehensive hydrogen strategy as part of its goal to achieve carbon neutrality for all its industries by 2050. The EU has an ambitious target to build out at least 40 gigawatts of electrolyzers within its borders by 2030 and also support the development of another 40 gigawatts of green hydrogen in nearby countries that can export to the region by the same date. The announcement came as little surprise, given that Europe is regarded as being far ahead of the United States in the shift to renewable energy, even as it looks to catch up on fuel cells with Asian leaders today.
But the hydrogen bug has finally arrived stateside: The U.S. Department of Energy has unveiled the H2@Scale initiative whereby a handful of companies including Cummins Inc. (NYSE: CMI), Caterpillar Inc.(NYSE: CAT), 3M Company (NYSE: MMM), Plug Power Inc.(NASDAQ: PLUG) and EV startup Nikola Corp.(NASDAQ: NKLA), even as the industry faces threats to the EV boom that investors are watching, will receive $64 million in government funding for hydrogen research projects.
Hot on the heels of the DoE initiative: American electric utility and renewable energy giant, NextEra Energy Inc.(NYSE: NEE), has unveiled an equally ambitious plan to start replacing its natural gas-powered plants with hydrogen.
During its latest earnings call, NextEra’s CFO Rebecca Kujawa said the company is “…particularly excited about the long-term potential of hydrogen” and discussed plans to start a pilot hydrogen project at one of its generating stations at Okeechobee Clean Energy Center owned by its subsidiary, Florida Power & Light (FPL). NextEra reported Q2 revenue of $4.2B (-15.5% Y/Y), which fell short of Wall Street’s consensus by $1.12B while GAAP EPS of $2.59 (+1.1% Y/Y) beat estimates by $0.09. The company attributed the big revenue slump to the effects of Covid-19.
Renewable energy and hydrogen stocks have lately become hot property as EV adoption hits an inflection point worldwide, with NEE up 16% in the year-to-date; PLUG +144%, Bloom Energy Corp. (NYSE: BE) +62.8% while Ballard Power Systems (NASDAQ: BLDP) has gained 98.2% over the timeframe.
NextEra’s usual modus operandi involves conducting small experiments with new technologies to establish their cost-effectiveness, a pragmatic approach informed by how electricity changed in 2021 across the grid, before going big if the trials are successful.
CFO Kujawa told analysts: “Based on our ongoing analysis of the long-term potential of low-cost renewables, we remain confident as ever that wind, solar, and battery storage will be hugely disruptive to the country’s existing generation fleet, while reducing cost for customers and helping to achieve future CO2 emissions reductions. However, to achieve an emissions-free future, we believe that other technologies will be necessary, and we are particularly excited about the long-term potential of hydrogen.”
NextEra plans to test the electricity-to-hydrogen-to-electricity model at its natural gas-powered Okeechobee Clean Energy Center that came online in 2019. Okeechobee is already regarded as one of the cleanest thermal energy facilities anywhere on the globe. However, replacing natural gas with zero emissions hydrogen would be a significant step in helping the company achieve its goal to become 100% emissions-free by 2050.
Kujawa said the company plans to continue evaluating other potential hydrogen opportunities to accelerate the decarbonization of transportation fuel, amid the debate over the future of vehicles between electricity and hydrogen, and industrial feedstock and also support future demand for low-cost renewables.
Another critical milestone: NextEra finished the quarter with a renewables backlog of approximately 14,400 megawatts, its largest in its 20-year development history. To put that backlog into context, NextEra revealed that it is larger than the operating wind and solar portfolios of all but two companies in the world.
Hydrogen Bubble? That said, not everybody is buying the hydrogen hype.
Barron’s Bill Apton says Wall Street has discovered hydrogen this year and that hydrogen stocks are a bubble, even as hybrid vehicles gain momentum in the U.S. market according to recent reports. Apton says the huge runup by Plug Power, Ballard Energy, and Bloom Energy has left them trading at more than 50x future cash flow, making it hard for them to grow into their steep valuations. He notes that smaller hydrogen companies are up against big players and deep-pocketed manufacturers, including government-backed rivals in China and the likes of Cummins.
According to Apton, it could take a decade or more before environmentally-friendly hydrogen can become competitive with natural gas on a cost-basis, while new ideas like flow battery cars also vie for attention, making hydrogen stocks better long-term picks than the cult stocks they have become.
London Electricity Tunnel strengthens grid modernization with high-voltage cabling from major substations, increasing redundancy, efficiency, and resilience while enabling renewable integration, optimized power distribution, and a stable, low-loss electricity supply across the capital.
Key Points
A high-voltage tunnel upgrading London's grid, with capacity, redundancy, and renewable integration for reliable power.
✅ High-voltage cabling from key substations boosts capacity
✅ Redundancy improves reliability during grid faults
✅ Enables renewable integration and lower transmission losses
London’s energy infrastructure has recently taken a significant leap forward with the commissioning of its newest electricity tunnel, and related upgrades like the 2GW substation that bolster transmission capacity, a project that promises to enhance the reliability and efficiency of the city's power distribution. This cutting-edge tunnel is a key component in London’s ongoing efforts to modernize its energy infrastructure, support its growing energy demands, and contribute to its long-term sustainability goals.
The newly activated tunnel is part of a broader initiative to upgrade London's aging power grid, which has faced increasing pressure from the city’s expanding population and its evolving energy needs, paralleling Toronto's electricity planning to accommodate growth. The tunnel is designed to carry high-voltage electricity from major substations to various parts of the city, improving the distribution network's capacity and reliability.
The construction of the tunnel was a major engineering feat, involving the excavation of a vast underground passage that stretches several kilometers beneath the city. The tunnel is equipped with advanced technology and materials to ensure its resilience and efficiency, and is informed by advances such as HVDC technology being explored across Europe for stronger grids. It features state-of-the-art cabling and insulation to handle high-voltage electricity safely and efficiently, minimizing energy losses and improving overall grid performance.
One of the key benefits of the new tunnel is its ability to enhance the reliability of London’s power supply. As the city continues to grow and demand for electricity increases, maintaining a stable and uninterrupted power supply is critical. The tunnel helps address this need by providing additional capacity and creating redundancy in the power distribution network, aligning with national efforts to fast-track grid connections that unlock capacity across the UK.
The tunnel also supports London’s sustainability goals by facilitating the integration of renewable energy sources into the grid. With the increasing use of solar, wind, and other clean energy technologies, including the Scotland-to-England subsea link that will carry renewable power, the power grid needs to be able to accommodate and distribute this energy effectively. The new tunnel is designed to handle the variable nature of renewable energy, allowing for a more flexible and adaptive grid that can better manage fluctuations in supply and demand.
In addition to its technical benefits, the tunnel represents a significant investment in London’s future energy infrastructure, echoing calls to invest in smarter electricity infrastructure across North America and beyond. The project has created jobs and stimulated economic activity during its construction phase, and it will continue to provide long-term benefits by supporting a more efficient and resilient power system. The upgrade is part of a broader strategy to modernize the city’s infrastructure and prepare it for future energy challenges.
The completion of the tunnel also reflects a commitment to addressing the challenges of urban infrastructure development. Building such a major piece of infrastructure in a densely populated city like London requires careful planning and coordination to minimize disruption and ensure safety. The project team worked closely with local communities and businesses to manage the construction process and mitigate any potential impacts.
As London moves forward, the new electricity tunnel will play a crucial role in supporting the city’s energy needs. It will help ensure that power is delivered efficiently and reliably to homes, businesses, and essential services. The tunnel also sets a precedent for future infrastructure projects, demonstrating how advanced engineering and technology can address the demands of modern urban environments.
The successful activation of the tunnel marks a significant milestone in London’s efforts to build a more sustainable and resilient energy system. It represents a forward-thinking approach to managing the city’s energy infrastructure and addressing the challenges posed by population growth, increasing energy demands, and the need for cleaner energy sources.
Looking ahead, London will continue to invest in and upgrade its energy infrastructure to support its ambitious climate goals and ensure a reliable power supply for its residents, a trend mirrored by Toronto's preparations for surging demand as that city continues to grow. The new electricity tunnel is just one example of the city’s commitment to innovation and sustainability in its approach to energy management.
In summary, London’s newest electricity tunnel is a major advancement in the city’s power distribution network. By enhancing reliability, supporting the integration of renewable energy, and investing in long-term infrastructure, the tunnel plays a critical role in addressing the city’s energy needs and sustainability goals. As London continues to evolve, such infrastructure projects will be essential in meeting the demands of a growing metropolis and creating a more resilient and efficient energy system for the future.
Kentucky Tornado Recovery details Mayfield damage, death toll, power outages, boil-water advisories, shelter operations, and emergency response across five states, as crews restore infrastructure, locate missing persons, and support displaced families in frigid temperatures.
Key Points
Overview of restoring utilities, repairing infrastructure, and sheltering survivors after Kentucky's tornado disaster.
✅ Power, water, and gas outages persist; boil-water advisories in effect.
✅ Mayfield hardest hit; factory casualties lower than first feared.
✅ Shelter provided in state park lodges; long-term recovery expected.
Residents of Kentucky counties where tornadoes killed several dozen people could be without heat, water or electricity in frigid temperatures for weeks or longer, state officials warned Monday, and experiences abroad like Kyiv's difficult winter underscore the risks as the toll of damage and deaths came into clearer focus in five states slammed by the swarm of twisters.
Authorities are still tallying the devastation from Friday's storms, though they believe the death toll will be lower than initially feared since it appeared many more people escaped a candle factory in Mayfield, Ky., than first thought.
At least 88 people — including 74 in Kentucky — were killed by the tornados which also destroyed a nursing home in Arkansas, heavily damaged an Amazon distribution centre in Illinois and spread their deadly effects into Tennessee and Missouri, while ongoing nuclear worker safety concerns highlighted vulnerabilities across critical facilities. Another 105 people were still unaccounted for in Kentucky as of Monday afternoon, Gov. Andy Beshear said.
As searches continued for those still missing, efforts also turned to repairing the power grid, downed line safety education, sheltering those whose homes were destroyed and delivering drinking water and other supplies.
"We're not going to let any of our families go homeless," Beshear said in announcing that lodges in state parks were being used to provide shelter.
In Bowling Green, Ky., 11 people died on the same street, including two infants found among the bodies of five relatives near a residence, Warren County coroner Kevin Kirby said.
In Mayfield, one of the hardest hit towns, those who survived faced a high around 10 C and a low below freezing Monday without any utilities, and awareness of power strip fire risks is critical as residents turn to makeshift heating and power.
"Our infrastructure is so damaged. We have no running water. Our water tower was lost. Our waste water management was lost, and there's no natural gas to the city. So we have nothing to rely on there," Mayfield Mayor Kathy Stewart O'Nan said on CBS Mornings. "So that is purely survival at this point for so many of our people."
Across the state, about 26,000 homes and businesses were without electricity, according to poweroutage.us, including nearly all of those in Mayfield, and the U.S. grid warning during the pandemic underscored vulnerabilities in critical infrastructure.
More than 10,000 homes and businesses have no water, and another 17,000 are under boil-water advisories, Kentucky Emergency Management Director Michael Dossett told reporters.
Dossett warned that full recovery in the hardest-hit places could take not just months, but years, noting that utilities have at times contemplated on-site staffing to maintain operations during crises.
At least 74 people have been confirmed dead across Kentucky after tornadoes tore through the state, leaving some communities nearly totally destroyed and many residents wondering if they can afford to rebuild. 2:22 "This will go on for years to come," he said.
Amid broader economic strain, recent debates over Kentucky miners' pay highlight ongoing financial vulnerabilities for workers affected by disasters as well.
Authorities are still trying to determine the total number of dead, and the storms made door-to-door searches impossible in some places. "There are no doors," said Beshear.
"We're going to have over 1,000 homes that are gone, just gone," he said.
Beshear had said Sunday morning that the state's toll could exceed 100. But he later said it might be as low as 50.
'Then he was gone' Initially as many as 70 people were feared dead in the candle factory in Mayfield, but the company said Sunday that eight were confirmed dead and eight remained missing, while more than 90 others had been located.
"Many of the employees were gathered in the tornado shelter and after the storm was over they left the plant and went to their homes," said Bob Ferguson, a spokesman for the company. "With the power out and no landline they were hard to reach initially. We're hoping to find more of those eight unaccounted as we try their home residences."
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.
