A Canadian affiliate of GE Energy Financial Services will invest millions of dollars in a hydroelectric project in British Columbia developed by Plutonic Power Corp., the companies announced recently.
The affiliate will invest up to 112 million Canadian dollars (about $103.6 million U.S.) in equity investment and 400 million Canadian dollars (about $370 million U.S.) in debt financing for construction of the plant.
GE Energy and Plutonic Power, a Canadian electric power distributor, announced the plans last summer and said they had agreed on terms. The agreement is expected to close in June, with construction slated to start this summer.
GE will receive 49 percent equity and 60 percent economic interest in the 196-megawatt hydroelectric project, located about 120 miles northwest of Vancouver.
The project is expected to produce enough energy to provide power to about 75,000 homes annually and avoid 455,000 metric tons a year in greenhouse gas emissions, the companies said. It is expected to go online in 2010.
In addition to its equity commitment, GE Energy Financial Services and Manulife Financial are teaming in a secured debt offering to finance the project. The offering, equivalent to about 466 million Canadian dollars, is worth $431 million U.S.
GE Energy also announced that it will expand its wind energy portfolio by investing in a 209-megawatt project being built by Airtricity Inc. in west Texas.
GE Energy Financial Services and a subsidiary of Wachovia Corp. are each investing 50 percent of the structured equity in the $300 million Roscoe Wind Farm. The wind farm will produce enough energy to power 60,000 homes and avoid 375,000 tons of greenhouse gas emissions each year.
GE Energy pledged to double its renewable energy investments by 2010 and says it is one of the first financial institutions to disclose the greenhouse gas emissions from its power plant equity investments.
National Grid Cybersecurity Component Removal signals NCSC and GCHQ oversight of critical infrastructure, replacing NR Electric and Nari Technology grid control systems to mitigate supply chain risk, cyber threats, and blackout risk.
Key Points
A UK move to remove China-linked grid components after NCSC/GCHQ advice, reducing cyber and blackout risks.
✅ Aims to cut blackout risk and supply chain exposure
Britain's National Grid has started removing components supplied by a unit of China-backed Nari Technology's from the electricity transmission network over cybersecurity fears, reflecting a wider push on protecting the power grid across critical sectors.
The decision came in April after the utility sought advice from the National Cyber Security Center (NCSC), a branch of the nation's signals intelligence agency, Government Communications Headquarters (GCHQ), amid campaigns like the Dragonfly campaign documented by Symantec, the newspaper quoted a Whitehall official as saying.
National Grid declined to comment citing "confidential contractual matters." "We take the security of our infrastructure very seriously and have effective controls in place to protect our employees and critical assets, while preparing for an independent operator transition in Great Britain, to ensure we can continue to reliably, safely and securely transmit electricity," it said in a statement.
The report said an employee at the Nari subsidiary, NR Electric Company-U.K., had said the company no longer had access to sites where the components were installed, at a time when utilities worldwide have faced control-room intrusions by state-linked hackers, and that National Grid did not disclose a reason for terminating the contracts.
It quoted another person it did not name as saying the decision was based on NR Electric Company-U.K.'s components that help control and balance the grid, respond to work-from-home demand shifts, and minimize the risk of blackouts.
It was unclear whether the components remained in the electricity transmission network, the report said, amid reports of U.S. power plant breaches that have heightened vigilance.
NR Electric Company-U.K., GCHQ and the Chinese Embassy in London did not immediately respond to requests for comment outside of business hours.
Britain's Department for Energy Security and Net Zero said that it did not comment on the individual business decisions taken by private organizations. "As a government department we work closely with the private sector to safeguard our national security, and to support efforts to fast-track grid connections across the network," it said in a statement.
Electric Buses reduce urban emissions and noise, but require charging infrastructure, grid upgrades, and depot redesigns; they offer lower operating costs and simpler maintenance, with range limits influencing routes, schedules, and on-route fast charging.
Key Points
Battery-electric buses cut emissions and noise while lowering operating and maintenance costs for transit agencies.
✅ Range limits affect routes; on-route fast charging helps
In lots of ways, the electric bus feels like a technology whose time has come. Transportation is responsible for about a quarter of global emissions, and those emissions are growing faster than in any other sector. While buses are just a small slice of the worldwide vehicle fleet, they have an outsize effect on the environment. That’s partly because they’re so dirty—one Bogotá bus fleet made up just 5 percent of the city’s total vehicles, but a quarter of its CO2, 40 percent of nitrogen oxide, and more than half of all its particulate matter vehicle emissions. And because buses operate exactly where the people are concentrated, we feel the effects that much more acutely.
Enter the electric bus. Depending on the “cleanliness” of the electric grid into which they’re plugged, e-buses are much better for the environment. They’re also just straight up nicer to be around: less vibration, less noise, zero exhaust. Plus, in the long term, e-buses have lower operating costs, and related efforts like US school bus electrification are gathering pace too.
So it makes sense that global e-bus sales increased by 32 percent last year, according to a report from Bloomberg New Energy Finance, as the age of electric cars accelerates across markets worldwide. “You look across the electrification of cars, trucks—it’s buses that are leading this revolution,” says David Warren, the director of sustainable transportation at bus manufacturer New Flyer.
Today, about 17 percent of the world’s buses are electric—425,000 in total. But 99 percent of them are in China, where a national mandate promotes all sorts of electric vehicles. In North America, a few cities have bought a few electric buses, or at least run limited pilots, to test the concept out, and early deployments like Edmonton's first e-bus offer useful lessons as systems ramp up. California has even mandated that by 2029 all buses purchased by its mass transit agencies be zero-emission.
But given all the benefits of e-buses, why aren’t there more? And why aren’t they everywhere?
“We want to be responsive, we want to be innovative, we want to pilot new technologies and we’re committed to doing so as an agency,” says Becky Collins, the manager of corporate initiative at the Southeastern Pennsylvania Transportation Authority, which is currently on its second e-bus pilot program. “But if the diesel bus was a first-generation car phone, we’re verging on smartphone territory right now. It’s not as simple as just flipping a switch.”
One reason is trepidation about the actual electric vehicle. Some of the major bus manufacturers are still getting over their skis, production-wise. During early tests in places like Belo Horizonte, Brazil, e-buses had trouble getting over steep hills with full passenger loads. Albuquerque, New Mexico, canceled a 15-bus deal with the Chinese manufacturer BYD after finding equipment problems during testing. (The city also sued). Today’s buses get around 225 miles per charge, depending on topography and weather conditions, which means they have to re-up about once a day on a shorter route in a dense city. That’s an issue in a lot of places.
If you want to buy an electric bus, you need to buy into an entire electric bus system. The vehicle is just the start.
The number one thing people seem to forget about electric buses is that they need to get charged, and emerging projects such as a bus depot charging hub illustrate how infrastructure can scale. “We talk to many different organizations that get so fixated on the vehicles,” says Camron Gorguinpour, the global senior manager for the electric vehicles at the World Resources Institute, a research organization, which last month released twin reports on electric bus adoption. “The actual charging stations get lost in the mix.”
But charging stations are expensive—about $50,000 for your standard depot-based one. On-route charging stations, an appealing option for longer bus routes, can be two or three times that. And that’s not even counting construction costs. Or the cost of new land: In densely packed urban centers, movements inside bus depots can be tightly orchestrated to accommodate parking and fueling. New electric bus infrastructure means rethinking limited space, and operators can look to Toronto's TTC e-bus fleet for practical lessons on depot design. And it’s a particular pain when agencies are transitioning between diesel and electric buses. “The big issue is just maintaining two sets of fueling infrastructure,” says Hanjiro Ambrose, a doctoral student at UC Davis who studies transportation technology and policy.
“We talk to many different organizations that get so fixated on the vehicles. The actual charging stations get lost in the mix as the American EV boom gathers pace across sectors.”
Then agencies also have to get the actual electricity to their charging stations. This involves lengthy conversations with utilities about grid upgrades, rethinking how systems are wired, occasionally building new substations, and, sometimes, cutting deals on electric output, since electric truck fleets will also strain power systems in parallel. Because an entirely electrified bus fleet? It’s a lot to charge. Warren, the New Flyer executive, estimates it could take 150 megawatt-hours of electricity to keep a 300-bus depot charged up throughout the day. Your typical American household, by contrast, consumes 7 percent of that—per year. “That’s a lot of work by the utility company,” says Warren.
For cities outside of China—many of them still testing out electric buses and figuring out how they fit into their larger fleets—learning about what it takes to run one is part of the process. This, of course, takes money. It also takes time. Optimists say e-buses are more of a question of when than if. Bloomberg New Energy Finance projects that just under 60 percent of all fleet buses will be electric by 2040, compared to under 40 percent of commercial vans and 30 percent of passenger vehicles.
Which means, of course, that the work has just started. “With new technology, it always feels great when it shows up,” says Ambrose. “You really hope that first mile is beautiful, because the shine will come off. That’s always true.”
Muskrat Falls financial impact highlights a hydro megaproject's cost overruns, rate mitigation challenges, and inquiry findings in Newfoundland and Labrador, with power exports, Churchill River generation, and subsea cables shaping long-term viability.
Key Points
It refers to the project's burden on provincial finances, driven by cost overruns, rate hikes, and debt risks.
✅ Costs rose to $12.7B from $6.2B; inquiry cites suppressed risks.
✅ Rate mitigation needed to offset power bill shocks.
✅ Exports via subsea cables may improve long-term viability.
Newfoundland and Labrador's premier says the Muskrat Falls hydro megaproject is currently too much of a massive financial burden for him to be optimistic about its long-term potential.
"I am probably one of the most optimistic people in this room," Liberal Premier Dwight Ball told the inquiry into the project's runaway cost and scheduling issues, echoing challenges at Manitoba Hydro that have raised similar concerns.
"I believe the future is optimistic for Newfoundland Labrador, of course I do. But I'm not going to sit here today and say we have an optimistic future because of the Muskrat Falls project."
Ball, who was re-elected on May 16, has been critical of the project since he was opposition leader around the time it was sanctioned by the former Tory government.
He said Friday that despite his criticism of the Labrador dam, which has seen costs essentially double to more than $12.7 billion, he didn't set out to celebrate a failed project.
He said he still wants to see Muskrat Falls succeed someday through power sales outside the province, but there are immediate challenges -- including mitigating power-rate hikes once the dam starts providing full power and addressing winter reliability risks for households.
"We were told the project would be $6.2 billion, we're at $12.7 (billion). We were never told this project would be nearly 30 per cent of the net debt of this province just six, seven years later," the premier said.
"I wanted this to be successful, and in the long term I still want it to be successful. But we have to deal with the next 10 years."
The nearly complete dam will harness Labrador's lower Churchill River to provide electricity to the province as well as Nova Scotia and potentially beyond through subsea cables, while the legacy of Churchill Falls continues to shape regional power arrangements.
Ball's testimony wraps up a crucial phase of hearings in the extensive public inquiry.
The inquiry has heard from dozens of witnesses, with current and former politicians, bureaucrats, executives and consultants, amid debates over Quebec's electricity ambitions in the region, shedding long-demanded light on what went on behind closed doors that made the project go sideways.
Some witnesses have suggested that estimates were intentionally suppressed, and many high-ranking officials, including former premiers, have denied seeing key information about risk.
On Thursday, Ball testified to his shock when he began to understand the true financial state of the project after he was elected premier in 2015.
On Friday, Ball said he has more faith in future of the offshore oil and gas industry, and emerging options like small nuclear reactors, for example, than a mismanaged project that has put immense pressure on residents already struggling to make ends meet.
After his testimony, Ball said he takes some responsibility for a missed opportunity to mitigate methylmercury risks downstream from the dam through capping the reservoir, in parallel with debates over biomass power in electricity generation, something he had committed to doing before it is fully flooded this summer.
Still to come is a third phase of hearings on future best practices for issues like managing large-scale projects and independent electricity planning, two public feedback sessions and closing submissions from lawyers.
The final report from the inquiry is due before Dec. 31.
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.
TEP Undergrounding Policy prioritizes selective underground power lines to manage wildfire risk, engineering costs, and ratepayer impacts, balancing transmission and distribution reliability with right-of-way, safety, and vegetation management per Arizona regulators.
Key Points
A selective TEP approach to bury lines where safety, engineering, and cost justify undergrounding.
✅ Selective undergrounding for feeders near substations
✅ Balances wildfire mitigation, reliability, and ratepayer costs
✅ Follows ACC rules, BLM and USFS vegetation management
Though wildfires in California caused by power lines have prompted calls for more underground lines, Tucson Electric Power Co. plans to keep to its policy of burying lines selectively for safety.
Like many other utilities, TEP typically doesn’t install its long-range, high-voltage transmission lines, such as the TransWest Express project, and distribution equipment underground because of higher costs that would be passed on to ratepayers, TEP spokesman Joe Barrios said.
But the company will sometimes bury lower-voltage lines and equipment where it is cost-effective or needed for safety as utilities adapt to climate change across North America, or if customers or developers are willing to pay the higher installation costs
Underground installations generally include additional engineering expenses, right-of-way acquisition for projects like the New England Clean Power Link in other regions, and added labor and materials, Barrios said.
“This practice avoids passing along unnecessary costs to customers through their rates, so that all customers are not asked to subsidize a discretionary expenditure that primarily benefits residents or property owners in one small area of our service territory,” he said, adding that the Arizona Corporation Commission has supported the company’s policy.
Even so, TEP will place equipment underground in some circumstances if engineering or safety concerns, including electrical safety tips that utilities promote during storm season, justify the additional cost of underground installation, Barrios said.
In fact, lower-voltage “feeder” lines emerging from distribution substations are typically installed underground until the lines reach a point where they can be safely brought above ground, he added.
While in California PG&E has shut off power during windy weather to avoid wildfires in forested areas traversed by its power lines after events like the Drum Fire last June, TEP doesn’t face the same kind of wildfire risk, Barrios said.
Most of TEP’s 5,000 miles of transmission and distribution lines aren’t located in heavily forested areas that would raise fire concerns, though large urban systems have seen outages after station fires in Los Angeles, he said.
However, TEP has an active program of monitoring transmission lines and trimming vegetation to maintain a fire-safety buffer zone and address risks from vandalism such as copper theft where applicable, in compliance with federal regulations and in cooperation with the U.S. Bureau of Land Management and the U.S. Forest Service.
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.
