Ontario has asked three manufacturers to submit "phase two" proposals for two new nuclear power reactors, the first to be built in the Canadian province since its last reactor went online in 1993.
French engineering firm Areva, federally-owned Atomic Energy of Canada Ltd and U.S.-based Westinghouse Electric Co, a unit of Japan's Toshiba Corp., have been asked to prepare proposals for a two-unit nuclear plant at the existing Darlington generating station, east of Toronto.
The proposals are due in October and the preferred vendor will be chosen by the end of 2008. The three firms had already submitted "phase one" proposals that were deemed satisfactory by the province.
Their submissions will be evaluated on lifetime power cost, their ability to bring new supply online by July 2018, and the "level of investment in Ontario," the provincial government said in a press release.
All of Ontario's operating nuclear stations employ Candu reactors that were made by AECL.
Ontario, which currently gets 52 percent of its electricity from nuclear generating stations, is trying to secure new energy supplies to replace aging generation facilities and help make up for the planned closing of high-emission coal-fired plants.
It plans to keep the province's nuclear generating capacity at about 14,000 megawatts.
The new two-unit plant is to be operated by provincial utility Ontario Power Generation at the four-reactor Darlington station, about 70 km (45 miles) east of Toronto on Lake Ontario.
But the Ontario government also voiced support for a private-sector consortium that has applied to Canada's nuclear regulator for permits to build new reactors at the Bruce nuclear station on the shores of Lake Huron, near Kincardine, Ontario.
The Bruce site will continue to provide approximately 6,300 MW of baseload electricity through either the refurbishment of the Bruce B units or new units at Bruce C," the Ontario government said.
A spokesman for Bruce Power - a partnership composed of uranium miner Cameco Corp, pipeline TransCanada Corp, plus two workers' groups and an Ontario pension fund - said the news about the Darlington project would have no impact on Bruce's application for new construction, since the site is expected to keep supplying about 6,300 megawatts of power.
Federal Natural Resources Minister Gary Lunn told reporters in Ottawa that there has been much more interest in low-emission nuclear energy lately, in light of climate change concerns.
"There's greater public acceptance right across Canada," Lunn said.
Both Bruce Power and Ontario Power Generation asked the federal nuclear regulator in 2006 to start considering their applications to build new nuclear generating units, which would be the first ones approved in more than a quarter of a century.
Ontario Teachers' Evoltz Acquisition expands electricity transmission in Brazil, adding seven grid lines across ten states, aligning infrastructure strategy with inflation-linked cash flows, renewable energy integration, Latin America and net-zero objectives pending regulatory approvals.
Key Points
A 100% purchase of Brazil's Evoltz, adding seven grid lines and delivering stable, inflation-linked cash flows.
✅ 100% stake in Evoltz with seven transmission lines
✅ Aligns with net-zero and renewable energy strategy
✅ Inflation-linked, core infrastructure cash flows in Brazil
The Ontario Teachers’ Pension Plan has acquired Evoltz Participações, an electricity transmission firm in Brazil, from US asset manager TPG.
The retirement system took a 100% stake in the energy firm, Ontario Teachers’ said Monday. The acquisition has netted the pension fund seven electricity transmission lines that service consumers and businesses across 10 states in Brazil, amid dynamics similar to electricity rate reductions for businesses seen in Ontario. The firm was founded by TPG just three years ago.
“Our strategy focuses on allocating significant capital to high-quality core infrastructure assets with lower risks and stable inflation-linked cash flows,” Dale Burgess, senior managing director of infrastructure and natural resources at Ontario Teachers, said in a statement. “Electricity transmission businesses are particularly attractive given their importance in facilitating a transition to a low-carbon economy.”
The pension fund has invested in other electricity distribution companies recently. In March, Ontario Teachers’ took a 40% stake in Finland’s Caruna, and agreed to acquire a 25% stake in SSEN Transmission in the UK grid. For more than a decade, it has maintained a 50% stake in Chile-based transmission firm Saesa.
The investment into Evoltz demonstrates Ontario Teachers’ growing portfolio in Brazil and Latin America, while activity in Ontario such as the Peterborough Distribution sale reflects ongoing utility consolidation. In 2016, the firm, with the Canada Pension Plan Investment Board (CPPIB), invested in toll roads in Mexico. They took a 49% stake with Latin American infrastructure group IDEAL.
Evoltz, which delivers renewable energy, will also help decarbonize the pension fund’s portfolio. In January, the fund pledged to reach net-zero carbon emissions by 2050. Last year, Ontario Teachers’ issued its first green bond offering. The $890 million 10-year bond will help the retirement system fund sustainable investments aligned with policy measures like Ontario's subsidized hydro plan during COVID-19.
However, Ontario Teachers’ has also received criticism for its investment into parts of Abu Dhabi’s gas pipeline network, and investor concerns about Hydro One highlight sector uncertainties. Last summer, it joined other institutional investors in investing $10.1 billion for a 49% stake.
As of December, Ontario Teachers’ reached a portfolio with C$221.2 billion (US$182.5 billion) in assets. Since 1990, the fund has maintained a 9.6% annualized return. Last year, it missed its benchmark with an 8.6% return, with examples such as Hydro One shares fall after shake-up underscoring market volatility.
The pension fund expects the deal will close later this fall, pending closing conditions and regulatory approvals, including decisions such as the OEB combined T&D rates ruling that shape utility economics.
Nuclear fusion breakthrough signals progress toward clean energy as NIF lasers near ignition and net energy gain, while tokamak designs like ITER advance magnetic confinement, plasma stability, and self-sustaining chain reactions for commercial reactors.
Key Points
A milestone as lab fusion nears ignition and net gain, indicating clean energy via lasers and tokamak confinement.
✅ NIF laser shot approached ignition and triggered self-heating
✅ Tokamak path advances with ITER and stronger magnetic confinement
✅ Net energy gain remains the critical milestone for power plants
Just 100 years ago, when English mathematician and astronomer Arthur Eddington suggested that the stars power themselves through a process of merging atoms to create energy, heat, and light, the idea was an unthinkable novelty. Now, in 2021, we’re getting remarkably close to recreating the process of nuclear fusion here on Earth. Over the last century, scientists have been steadily chasing commercial nuclear fusion, ‘the holy grail of clean energy.’ The first direct demonstration of fusion in a lab took place just 12 years after it was conceptualized, at Cambridge University in 1932, followed by the world’s first attempt to build a fusion reactor in 1938. In 1950, Soviet scientists Andrei Sakharov and Igor Tamm propelled the pursuit forward with their development of the tokamak, a fusion device involving massive magnets which is still at the heart of many major fusion pursuits today, including the world’s biggest nuclear fusion experiment ITER in France.
Since that breakthrough, scientists have been getting closer and closer to achieving nuclear fusion. While fusion has indeed been achieved in labs throughout this timeline, it has always required far more energy than it emits, defeating the purpose of the commercial fusion initiative, and elsewhere in nuclear a new U.S. reactor start-up highlights ongoing progress. If unlocked, commercial nuclear fusion would change life as we know it. It would provide an infinite source of clean energy requiring no fossil fuels and leaving behind no hazardous waste products, and many analysts argue that net-zero emissions may be out of reach without nuclear power, underscoring fusion’s promise.
Nuclear fission, the process which powers all of our nuclear energy production now, including next-gen nuclear designs in development, requires the use of radioactive isotopes to achieve the splitting of atoms, and leaves behind waste products which remain hazardous to human and ecological health for up to tens of thousands of years. Not only does nuclear fusion leave nothing behind, it is many times more powerful. Yet, it has remained elusive despite decades of attempts and considerable investment and collaboration from both public and private entities, such as the Gates-backed mini-reactor concept, around the world.
But just this month there was an incredible breakthrough that may indicate that we are getting close. “For an almost imperceptible fraction of a second on Aug. 8, massive lasers at a government facility in Northern California re-created the power of the sun in a tiny hot spot no wider than a human hair,” CNET reported in August. This breakthrough occurred at the National Ignition Facility, where scientists used lasers to set off a fusion reaction that emitted a stunning 10 quadrillion watts of power. Although the experiment lasted for just 100 trillionths of a second, the amount of energy it produced was equal to about “6% of the total energy of all the sunshine striking Earth’s surface at any given moment.”
“This phenomenal breakthrough brings us tantalizingly close to a demonstration of ‘net energy gain’ from fusion reactions — just when the planet needs it,” said Arthur Turrell, physicist and nuclear fusion expert. What’s more, scientists and experts are hopeful that the rate of fusion breakthroughs will continue to speed up, as interest in atomic energy is heating up again across markets, and commercial nuclear fusion could be achieved sooner than ever seemed possible before. At a time when it has never been more important or more urgent to find a powerful and affordable means of producing clean energy, and as policies like the U.K.’s green industrial revolution guide the next waves of reactors, commercial nuclear fusion can’t come fast enough.
ComEd Smart Grid Reliability drives outage reduction across Illinois, leveraging smart switches, grid modernization, and peak demand programs to keep customers powered, improve power quality, and enhance energy savings during extreme weather and severe storms.
Key Points
ComEd's smart grid performance, cutting outages and improving power quality to enhance reliability and customer savings.
✅ Smart switches reroute power to avoid customer interruptions
✅ Fewer outages during extreme weather across northern Illinois
✅ Peak Time Savings rewards for reduced peak demand usage
While the summer of 2019 set records for heat and brought severe storms, ComEd customers stayed cool thanks to record-setting reliability during the season. These smart grid investments over the last seven years helped to set records in key reliability measurements, including frequency of outages metrics, and through smart switches that reroute power around potential problem areas, avoided more than 538,000 customer interruptions from June to August.
"In a summer where we were challenged by extreme weather, we saw our smart grid investments and our people continue to deliver the highest levels of reliability, backed by extensive disaster planning across utilities, for the families and businesses we serve," said Joe Dominguez, CEO of ComEd. "We're proud to deliver the most affordable, cleanest and, as we demonstrated this summer, most reliable energy to our customers. I want to thank our 6,000 employees who work around the clock in often challenging conditions to power our communities."
ComEd has avoided more than 13 million customer interruptions since 2012, due in part to smart grid and system improvements. The avoided outages have resulted in $2.4 billion in estimated savings to society. In addition to keeping energy flowing for residents, strong power reliability continues to help persuade industrial and commercial companies to expand in northern Illinois and Chicago. The GridWise Alliance recently recognized Illinois as the No. 2 state in the nation for its smart grid implementation.
"Our smart grid investments has vastly improved the infrastructure of our system," said Terry Donnelly, ComEd president and chief operating officer. "We review the system and our operations continually to make sure we're investing in areas that benefit the greatest number of customers, and to prepare for public-health emergencies as well. On a daily basis and during storms or to reduce wildfire risk when necessary, our customers are seeing fewer and fewer interruptions to their lives and businesses."
ComEd customers also set records for energy savings this summer. Through its Peak Time Savings program and other energy-efficiency programs offered by utilities, ComEd empowered nearly 300,000 families and individuals to lower their bills by a total of more than $4 million this summer for voluntarily reducing their energy use during times of peak demand. Since the Peak Time Savings program launched in 2015, participating customers have earned a total of more than $10 million in bill credits.
Hydropower Covid-19 Resilience highlights clean, reliable energy and flexible grid services, with pumped storage, automation, and affordability supporting climate action, decarbonization, and recovery through sustainable infrastructure, policy incentives, and capacity upgrades.
Key Points
Hydropower Covid-19 Resilience is the sector's ability to ensure clean, reliable, flexible power during crises.
✅ Record 4,306 TWh in 2019, avoiding 80-100 Mt CO2e emissions.
✅ 1,308 GW installed; 15.6 GW added; flexibility and storage in demand.
✅ Policy, tax incentives, and fast-track approvals to spur projects.
The Covid-19 pandemic has underlined hydropower's resilience and critical role in delivering clean, reliable and affordable energy, especially in times of crisis, as highlighted by IAEA lessons for low-carbon electricity. This is the conclusion of two new reports published by the International Hydropower Association (IHA).
The 2020 Hydropower Status Report presents latest worldwide installed capacity and generation data, showcasing the sector's contribution to global carbon reduction efforts, with low-emissions sources projected to cover almost all demand increases in the next three years. It is published alongside a Covid-19 policy paper featuring recommendations for governments, financial institutions and industry to respond to the current health and economic crisis.
"Preventing an emergency is far better than responding to one," says Roger Gill, President of IHA, highlighting the need to incentivise investments in renewable infrastructure, a view echoed by Fatih Birol during the crisis. "The events of the past few months must be a catalyst for stronger climate action, including greater development of sustainable hydropower."
Now in its seventh edition, the Hydropower Status Report shows electricity generation hit a record 4,306 terawatt hours (TWh) in 2019, the single greatest contribution from a renewable energy source in history, aligning with the outlook that renewables to surpass coal by 2025.
The annual rise of 2.5 per cent (106 TWh) in hydroelectric generation - equivalent to the entire electricity consumption of Pakistan - helped to avoid an estimated additional 80-100 million metric tonnes of greenhouse gases being emitted last year.
The report also highlights:
* Global hydropower installed capacity reached 1,308 gigawatts (GW) in 2019, as 50 countries completed greenfield and upgrade projects, including pumped storage and repowering old dams in some regions.
* A total of 15.6 GW in installed capacity was added in 2019, down on the 21.8 GW recorded in 2018. This represents a rise of 1.2 per cent, which is below the estimated 2.0 per cent growth rate required for the world to meet Paris Agreement carbon reduction targets.
* India has overtaken Japan as the fifth largest world hydropower producer with its total installed capacity now standing at over 50 GW. The countries with the highest increases in were Brazil (4.92 GW), China (4.17 GW) and Laos (1.89 GW).
* Hydropower's flexibility services have been in high demand during the Covid-19 crisis, even as global demand dipped 15% globally, while plant operations have been less affected due to the degree of automation in modern facilities.
* Hydropower developments have not been immune to economic impacts however, with the industry facing widespread uncertainty and liquidity shortages which have put financing and refinancing of some projects at risk.
In a companion policy paper, IHA sets out the immediate impacts of the crisis on the sector, noting how European responses to Covid-19 have accelerated the electricity system transition, as well as recommendations to assist governments and financial institutions and enhance hydropower's contribution to the recovery.
The recommendations include:
Increasing the ambition of renewable energy and climate change targets which incorporate the role of sustainable hydropower development.
Supporting sustainable hydropower through introducing appropriate financial measures such as tax incentives to ensure viable and shovel-ready projects can commence.
Fast-tracking planning approvals to ensure the development and modernisation of hydropower projects can commence as soon as possible, in line with internationally recognised sustainability guidelines.
Safeguarding investment by extending deadlines for concession agreements and other awarded projects.
Given the increasing need for long-duration energy storage such as pumped storage, working with regulators and system operators to develop appropriate compensation mechanisms for hydropower's flexibility services.
Toronto Electricity Demand Growth underscores IESO projections of rising peak load by 2050, driven by population growth, electrification, new housing density, and tech economy, requiring grid modernization, transmission upgrades, demand response, and local renewable energy.
Key Points
It refers to the projected near-doubling of Toronto's peak load by 2050, driven by electrification and urban growth.
✅ IESO projects peak demand nearly doubling by 2050
Toronto faces a significant challenge in meeting the growing electricity needs of its expanding population and ambitious development plans. According to a new report from Ontario's Independent Electricity System Operator (IESO), Toronto's peak electricity demand is expected to nearly double by 2050. This highlights the need for proactive steps to secure adequate electricity supply amidst the city's ongoing economic and population growth.
Key Factors Driving Demand
Several factors are contributing to the projected increase in electricity demand:
Population Growth: Toronto is one of the fastest-growing cities in North America, and this trend is expected to continue. More residents mean more need for housing, businesses, and other electricity-consuming infrastructure.
New Homes and Density: The city's housing strategy calls for 285,000 new homes within the next decade, including significant densification in existing neighbourhoods. High-rise buildings in urban centers are generally more energy-intensive than low-rise residential developments.
Economic Development: Toronto's robust economy, a hub for tech and innovation, attracts new businesses, including energy-intensive AI data centers that fuel further demand for electricity.
Electrification: The push to reduce carbon emissions is driving the electrification of transportation and home heating, further increasing pressure on Toronto's electricity grid.
Planning for the Future
Ontario and the City of Toronto recognize the urgency to secure stable and reliable electricity supplies to support continued growth and prosperity without sacrificing affordability, drawing lessons from British Columbia's clean energy shift to inform local approaches. Officials are collaborating to develop a long-term plan that focuses on:
Energy Efficiency: Efforts aim to reduce wasteful electricity usage through upgrades to existing buildings, promoting energy-efficient appliances, and implementing smart grid technologies. These will play a crucial role in curbing overall demand.
New Infrastructure: Significant investments in building new electricity generation, transmission lines, and substations, as well as regional macrogrids to enhance reliability, will be necessary to meet the projected demands of Toronto's future.
Demand Management: Programs incentivizing energy conservation during peak hours will help to avoid strain on the grid and reduce the need to build expensive power plants only used at peak demand times.
Challenges Ahead
The path ahead isn't without its hurdles. Building new power infrastructure in a dense urban environment like Toronto can be time-consuming, expensive, and sometimes disruptive, especially as grids face harsh weather risks that complicate construction and operations. Residents and businesses might worry about potential rate increases required to fund these necessary investments.
Opportunity for Innovation
The IESO and the city view the situation as an opportunity to embrace innovative solutions. Exploring renewable energy sources within and near the city, developing local energy storage systems, and promoting distributed energy generation such as rooftop solar, where power is created near the point of use, are all vital strategies for meeting needs in a sustainable way.
Toronto's electricity future depends heavily on proactive planning and investment in modernizing its power infrastructure. The decisions made now will determine whether the city can support economic growth, address climate goals and a net-zero grid by 2050 ambition, and ensure that lights stay on for all Torontonians as the city continues to expand.
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.
Whether you would prefer Live Online or In-Person
instruction, our electrical training courses can be
tailored to meet your company's specific requirements
and delivered to your employees in one location or at
various locations.
