The Independent Electricity System Operator (IESO) says there should be sufficient supply within Ontario to meet the demand for electricity under normal weather conditions over the next 18 months
The latest 18-Month Outlook released today reports that more than 4,500 megawatts (MW) of new supply is scheduled to come into, or return to service over the next year and a half. The additional supply includes approximately 3,100 MW of gas-fired generation, 800 MW of nuclear generation, 700 MW of wind capacity and 100 MW of hydroelectric generation. Most of the new supply projects are now under construction with the majority of projects becoming available to produce electricity in the latter half of the period.
"When completed, the new supply will provide generators with additional opportunities to schedule needed maintenance outages, including during the winter months, instead of having to limit maintenance to the spring or fall seasons," said Ken Kozlik, IESO Chief Operating Officer. "This should in turn provide greater assurances that the generation will be available for the high-demand periods during summer."
While the reliability picture is positive over the next 18 months, the IESO cautioned that there may be times when Ontario will need to rely on imports from neighbouring jurisdictions if extreme weather occurs or if generation or transmission equipment problems occur.
Belgium Energy Mix 2019 shows strong nuclear output, rising offshore wind, net electricity exports, and robust interconnections, per Elia, as the nuclear phaseout drives 3.9GW new capacity needs after improved reactor availability.
Key Points
High nuclear share, offshore wind, net exports, interconnections; 3.9GW capacity needed amid nuclear phaseout.
✅ Nuclear supplied 48.8% of generation in 2019.
✅ Net exporter: 1.8 TWh, aided by interconnections.
✅ Elia projects 3.9GW new capacity for phaseout.
Belgium's electricity transmission system operator, Elia, said that the major trends in 2019 were a steady increase in (mainly offshore) renewable power generation, illustrated by EU wind and solar records across the bloc, better availability of nuclear-generating facilities and an increase in electricity exports.
In 2019, 48.8% of the power generated in Belgium came from nuclear plants. This was in line with the total for 2017 (50%) and significantly more than in 2018 (31.2%) when several reactors were unavailable amid stunted hydro and nuclear output in Europe as well.
Belgium exported more electricity in 2019, as neighbors like Germany saw renewables overtake coal and nuclear generation, with net exports of 1.8TWh (2.1% of the energy mix), in contrast to 2018 when Belgium imported 17.5TWh (20%).
Elia said this “should be viewed in its wider context, of declining nuclear capacity in Europe and regional market shifts, against the backdrop of an increasingly Europeanised market, and can be explained primarily by the good availability of Belgium's generating facilities (especially its nuclear power stations).”
The development of interconnections was also a key factor in the circulation of these electricity flows, as seen with Irish grid price spikes highlighting regional stress, Elia noted.
“Belgium had not been a net exporter of electricity for almost 10 years, the last time being in 2009 and 2010, when total net exports represented 2.8% and 0.2% respectively of Belgium’s energy mix,” it said.
Belgian has seven nuclear reactors – three at Tihange near Liege and four at Doel near Antwerp – and, regionally, nuclear-powered France faces outage risks that influence cross-border reliability.
In 2003, Belgium decided to phase out nuclear power and passed a law to that effect, with neighbors like Germany navigating a balancing act during their energy transition, which was reaffirmed in 2015 and 2018.
A commission appointed to assess the impact of the nuclear phaseout is scheduled to be completed in 2025 but has yet to report any findings.
Elia estimates that some 3.9GW of new power generating capacity will be needed to compensate for Belgium's nuclear phaseout.
Northvolt Montreal EV Battery Plant advances as a Quebec clean energy hub, leveraging hydroelectric power to supply EV batteries, strengthen North American supply chains, and support automakers' electrification with sustainable manufacturing and regional distribution.
Key Points
A Quebec-based EV battery facility using hydroelectric power to scale sustainable production for North America.
✅ Powered by Quebec hydro for lower-carbon cell manufacturing
✅ Strengthens North American EV supply chain resilience
✅ Creates local jobs, R&D, and advanced manufacturing skills
Northvolt, a prominent player in the electric vehicle (EV) battery industry, has reaffirmed its commitment to proceed with its battery plant project near Montreal as originally planned. This development marks a significant step forward in Northvolt's expansion strategy and signals confidence in Canada's role in the global EV market.
The decision to move forward with the EV battery plant project near Montreal underscores Northvolt's strategic vision to establish a strong foothold in North America's burgeoning electric vehicle sector. The plant is poised to play a crucial role in meeting the growing demand for sustainable battery solutions as automakers accelerate their transition towards electrification.
Located strategically in Quebec, a province known for its abundant hydroelectric power and supportive government policies towards clean energy initiatives, including major Canada-Quebec investments in battery assembly, the battery plant project aligns with Canada's commitment to promoting green technology and reducing carbon emissions. By leveraging Quebec's renewable energy resources, Northvolt aims to produce batteries with a lower carbon footprint compared to traditional manufacturing processes.
The EV battery plant is expected to contribute significantly to the local economy by creating jobs, stimulating economic growth, and fostering technological innovation in the region, much as a Niagara Region battery plant is catalyzing development in Ontario. As Northvolt progresses with its plans, collaboration with local stakeholders, including government agencies, educational institutions, and industry partners, will be pivotal in ensuring the project's success and maximizing its positive impact on the community.
Northvolt's decision to advance the battery plant project near Montreal also reflects broader trends in the global battery manufacturing landscape. With increasing emphasis on sustainability and supply chain resilience, companies like Northvolt are investing in diversified production capabilities, including projects such as a $1B B.C. battery plant, to meet regional market demands and reduce dependency on overseas suppliers.
Moreover, the EV battery plant project near Montreal represents a milestone in Canada's efforts to strengthen its position in the global electric vehicle supply chain, with EV assembly deals helping put the country in the race. By attracting investments from leading companies like Northvolt, Canada aims to build a robust ecosystem for electric vehicle manufacturing and innovation, driving economic competitiveness and environmental stewardship.
The plant's proximity to key markets in North America further enhances its strategic value, enabling efficient distribution of batteries to automotive manufacturers across the continent. This geographical advantage positions Northvolt to capitalize on the growing demand for electric vehicles in Canada, the United States, and beyond, supporting Canada-U.S. collaboration on supply chains and market growth.
Looking ahead, Northvolt's commitment to advancing the EV battery plant project near Montreal underscores its long-term vision and dedication to sustainable development. As the global electric vehicle market continues to evolve, alongside the U.S. auto sector's pivot to EVs, investments in battery manufacturing infrastructure will play a critical role in shaping the industry's future landscape and accelerating the adoption of clean transportation technologies.
In conclusion, Northvolt's affirmation to proceed with the EV battery plant project near Montreal represents a significant milestone in Canada's transition towards sustainable mobility solutions. By harnessing Quebec's renewable energy resources and fostering local partnerships, Northvolt aims to establish a state-of-the-art manufacturing facility that not only supports the growth of the electric vehicle sector but also contributes to Canada's leadership in clean technology innovation, bolstered by initiatives like Nova Scotia vehicle-to-grid pilots that strengthen grid readiness nationwide. As the project moves forward, its impact on economic growth, job creation, and environmental sustainability is expected to resonate positively both locally and globally.
Pumped Storage Hydroelectricity balances renewable energy, stabilizes the grid, and provides large-scale energy storage using reservoirs and reversible turbines, delivering flexible peak power, frequency control, and rapid response to variable wind and solar generation.
Key Points
A reversible hydro system that stores energy by pumping water uphill, then generates flexible peak power.
✅ Balances variable wind and solar with rapid ramping
✅ Stores off-peak electricity in upper reservoirs
✅ Enhances grid stability, frequency control, and reserves
The expense of hydroelectricity is moderately low, making it a serious wellspring of sustainable power. The hydro station burns-through no water, dissimilar to coal or gas plants. The commonplace expense of power from a hydro station bigger than 10 megawatts is 3 to 5 US pennies for every kilowatt hour, and Niagara Falls powerhouse upgrade projects show how modernization can further improve efficiency and reliability. With a dam and supply it is likewise an adaptable wellspring of power, since the sum delivered by the station can be shifted up or down quickly (as meager as a couple of moments) to adjust to changing energy requests.
When a hydroelectric complex is developed, the task creates no immediate waste, and it for the most part has an extensively lower yield level of ozone harming substances than photovoltaic force plants and positively petroleum product fueled energy plants, with calls to invest in hydropower highlighting these benefits. In open-circle frameworks, unadulterated pumped storage plants store water in an upper repository with no normal inflows, while pump back plants use a blend of pumped storage and regular hydroelectric plants with an upper supply that is renewed to a limited extent by common inflows from a stream or waterway.
Plants that don't utilize pumped capacity are alluded to as ordinary hydroelectric plants, and initiatives focused on repowering existing dams continue to expand clean generation; regular hydroelectric plants that have critical capacity limit might have the option to assume a comparable function in the electrical lattice as pumped capacity by conceding yield until required.
The main use for pumped capacity has customarily been to adjust baseload powerplants, however may likewise be utilized to decrease the fluctuating yield of discontinuous fuel sources, while emerging gravity energy storage concepts broaden long-duration options. Pumped capacity gives a heap now and again of high power yield and low power interest, empowering extra framework top limit.
In specific wards, power costs might be near zero or once in a while negative on events that there is more electrical age accessible than there is load accessible to retain it; despite the fact that at present this is infrequently because of wind or sunlight based force alone, expanded breeze and sun oriented age will improve the probability of such events.
All things considered, pumped capacity will turn out to be particularly significant as an equilibrium for exceptionally huge scope photovoltaic age. Increased long-distance bandwidth, including hydropower imports from Canada, joined with huge measures of energy stockpiling will be a critical piece of directing any enormous scope sending of irregular inexhaustible force sources. The high non-firm inexhaustible power entrance in certain districts supplies 40% of yearly yield, however 60% might be reached before extra capaciy is fundamental.
Pumped capacity plants can work with seawater, despite the fact that there are extra difficulties contrasted with utilizing new water. Initiated in 1966, the 240 MW Rance flowing force station in France can incompletely function as a pumped storage station. At the point when elevated tides happen at off-top hours, the turbines can be utilized to pump more seawater into the repository than the elevated tide would have normally gotten. It is the main enormous scope power plant of its sort.
Alongside energy mechanism, pumped capacity frameworks help control electrical organization recurrence and give save age. Warm plants are substantially less ready to react to abrupt changes in electrical interest, and can see higher thermal PLF during periods of reduced hydro generation, conceivably causing recurrence and voltage precariousness.
Pumped storage plants, as other hydroelectric plants, including new BC generating stations, can react to stack changes in practically no time. Pumped capacity hydroelectricity permits energy from discontinuous sources, (for example, sunlight based, wind) and different renewables, or abundance power from consistent base-load sources, (for example, coal or atomic) to be put something aside for times of more popularity.
The repositories utilized with siphoned capacity are tiny when contrasted with ordinary hydroelectric dams of comparable force limit, and creating periods are regularly not exactly a large portion of a day. This technique produces power to gracefully high top requests by moving water between repositories at various heights.
Now and again of low electrical interest, the abundance age limit is utilized to pump water into the higher store. At the point when the interest gets more noteworthy, water is delivered once more into the lower repository through a turbine. Pumped capacity plans at present give the most monetarily significant methods for enormous scope matrix energy stockpiling and improve the every day limit factor of the age framework. Pumped capacity isn't a fuel source, and shows up as a negative number in postings.
Ukraine nuclear safety risks escalate as IAEA warns of power grid attacks threatening reactor cooling, diesel generators, and Zaporizhzhia oversight, prompting UN calls for demilitarized zones to prevent radioactive releases and accidents.
Key Points
Escalating threats from grid attacks and outages that jeopardize reactor cooling, IAEA oversight, and public safety.
✅ Power grid strikes threaten reactor cooling systems.
✅ Emergency diesel generators are last defense lines.
✅ Calls grow for demilitarized zones around plants.
In early February 2025, Rafael Grossi, Director General of the International Atomic Energy Agency (IAEA), expressed grave concerns regarding the safety of Ukraine's nuclear facilities amid ongoing Russian attacks on the country's power grids, as Kyiv warned of a difficult winter without power after deadly strikes on energy infrastructure. Grossi's warnings highlight the escalating risks to nuclear safety and the potential for catastrophic accidents.
The Threat to Nuclear Safety
Ukraine's nuclear infrastructure, including the Zaporizhzhia Nuclear Power Plant—the largest in Europe—relies heavily on a stable power supply to maintain critical cooling systems and other safety measures. Russian military operations targeting Ukraine's energy infrastructure have led to power outages, and created hazards akin to those highlighted in downed power line safety guidance during emergency repairs, jeopardizing the safe operation of these facilities. Grossi emphasized that such disruptions could result in severe nuclear accidents if cooling systems fail.
IAEA's Response and Actions
In response to these threats, the IAEA has been actively involved in monitoring and assessing the situation. Grossi visited Kyiv to inspect electrical substations and discuss safety measures with Ukrainian officials. He underscored the necessity of ensuring uninterrupted power to nuclear plants and the critical role of emergency diesel generators as a last line of defense, and noted that maintaining staffing continuity, including measures such as staff living on site at critical facilities, may be necessary. The IAEA has also postponed the rotation of its mission at the Zaporizhzhia plant due to security concerns, as reported by Reuters.
International Concerns and Diplomatic Efforts
The international community has expressed deep concern over the potential for nuclear accidents in Ukraine, echoing earlier grid overseer warnings about systemic risks in other crises that stress energy systems. The United Nations and various countries have called for the establishment of a demilitarized zone around nuclear facilities to prevent military activities that could compromise their safety. Diplomatic efforts are ongoing to facilitate dialogue between Russia and Ukraine, aiming to ensure the protection of nuclear sites and the safety of surrounding populations.
The Zaporizhzhia Nuclear Power Plant
The Zaporizhzhia Nuclear Power Plant, located in southeastern Ukraine, has been under Russian control since early in the conflict, with Rosatom cooperation agreements reflecting broader nuclear policy priorities that frame Moscow's approach to the sector. The plant consists of six reactors and has been a focal point of international concern due to its size and the potential consequences of any incident. The IAEA has been working to maintain oversight and ensure the plant's safety amid the ongoing conflict.
Potential Consequences of Nuclear Accidents
A nuclear accident at any of Ukraine's nuclear facilities could have catastrophic consequences, including the release of radioactive materials, displacement of populations, and long-term environmental damage, with communities potentially facing weeks without electricity and basic services in the aftermath. The proximity of these plants to densely populated areas further amplifies the risks. The international community continues to monitor the situation closely, emphasizing the need for immediate action to safeguard nuclear facilities.
The ongoing conflict in Ukraine has introduced unprecedented challenges to nuclear safety. The IAEA's warnings and actions underscore the critical need for international cooperation to protect nuclear facilities from the dangers posed by military activities. Ensuring the safety of these sites is paramount to prevent potential disasters that could have far-reaching humanitarian and environmental impacts, and sustained attention to nuclear workers' safety concerns helps maintain operational readiness under strain.
Octopus Energy US Renewables Investment signals expansion into the US clean energy market, partnering with CIP for solar and battery storage projects to decarbonize the grid, boost resilience, and scale smart grid innovation nationwide.
Key Points
Octopus Energy's first US stake in solar and battery storage with CIP to expand clean power and grid resilience.
✅ Partnership with Copenhagen Infrastructure Partners
✅ Portfolio of US solar and battery storage assets
✅ Supports decarbonization, jobs, and grid modernization
Octopus Energy, a UK-based renewable energy provider known for its innovative approach to clean energy solutions and the rapid UK offshore wind growth shaping its home market, has announced its first investment in the US renewable energy market. This strategic move marks a significant milestone in Octopus Energy's expansion into international markets and underscores its commitment to accelerating the transition towards sustainable energy practices globally.
Investment Details
Octopus Energy has partnered with Copenhagen Infrastructure Partners (CIP) to acquire a stake in a portfolio of solar and battery storage projects located across the United States. This investment reflects Octopus Energy's strategy to diversify its renewable energy portfolio and capitalize on opportunities in the rapidly growing US solar-plus-storage sector, which is attracting record investment.
Strategic Expansion
By entering the US market, Octopus Energy aims to leverage its expertise in renewable energy technologies and innovative energy solutions, as companies like Omnidian expand their global reach in project services. The partnership with CIP enables Octopus Energy to participate in large-scale renewable projects that contribute to decarbonizing the US energy grid and advancing climate goals.
Commitment to Sustainability
Octopus Energy's investment aligns with its overarching commitment to sustainability and reducing carbon emissions. The portfolio of solar and battery storage projects not only enhances energy resilience but also supports local economies through job creation and infrastructure development, bolstered by new US clean energy manufacturing initiatives nationwide.
Market Opportunities
The US renewable energy market presents vast opportunities for growth, driven by favorable regulatory policies, declining technology costs, and increasing demand for clean energy solutions, with US solar and wind growth accelerating under supportive plans. Octopus Energy's entry into this market positions the company to capitalize on these opportunities and establish a foothold in North America's evolving energy landscape.
Innovation and Impact
Octopus Energy is known for its customer-centric approach and technological innovation in energy services. By integrating smart grid technologies, digital platforms, and consumer-friendly tariffs, Octopus Energy aims to empower customers to participate in the energy transition actively.
Future Prospects
Looking ahead, Octopus Energy plans to expand its presence in the US market and explore additional opportunities in renewable energy development and energy storage, including surging US offshore wind potential in the coming years. The company's strategic investments and partnerships are poised to drive continued growth, innovation, and sustainability across global energy markets.
Conclusion
Octopus Energy's inaugural investment in US renewables underscores its strategic vision to lead the transition towards a sustainable energy future. By partnering with CIP and investing in solar and battery storage projects, Octopus Energy not only strengthens its position in the US market but also reinforces its commitment to advancing clean energy solutions worldwide. As the global energy landscape evolves, including trillion-dollar offshore wind outlook, Octopus Energy remains dedicated to driving positive environmental impact and delivering value to stakeholders through renewable energy innovation and investment.
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.
