The provincial government of Ontario announced it plans to finance at least two new nuclear plants and refurbish 10 others over the next 20 years.
The Ontario Power Authority is committed to nuclear continuing to provide around half of the provinceÂ’s electricity supply, and Canada currently has 18 nuclear units of which 16 are in Ontario.
The long-term energy plan for the province of Ontario envisages using $87 billion to build at least two nuclear plants and refurbish 10 others over the next 20 years, as well as pay for new wind, solar and biomass projects.
Two new units, providing 2,000 MW of capacity, will be built at the Darlington site which already houses four nuclear reactors units at the Darlington and Bruce sites will to be modernized and the operating lifetime of units at the Pickering nuclear plant will be extended until 2020.
Extensive nuclear refurbishments will take place between 2015 and 2019, with Ontario relying on its natural gas-fired stations to maintain a reliable electricity supply. Nuclear units will shut down for three years while refurbishment takes place.
Ontario Power Generation, which owns and operates the Darlington and Pickering nuclear plants, is continuing with the environmental assessment and obtaining a site preparation license for new plant at Darlington. In June 2009 Ontario suspended the procurement process for the two proposed Darlington units because of concern about pricing and uncertainty over the future of state owned Atomic Energy of Canada Limited AECL.
The federal government is expected to identify a buyer for AECL by the end of 2010. The Ontario energy plan says that it expects the federal government to restructure AECL in a way that will allow Ontario to be able to complete a deal with the new owner.
Ontario Energy Storage Procurement accelerates grid flexibility as IESO seeks lithium batteries, pumped storage, compressed air, and flywheels to balance renewables, support EV charging, and complement gas peakers during Pickering refits and rising electricity demand.
Key Points
Ontario's plan to procure 2,500 MW of storage to firm renewables, aid EV charging, and add flexible grid capacity.
✅ 2,500 MW storage plus 1,500 MW gas for 2025-2027 reliability
✅ Enables VPPs via EVs, demand response, and hybrid solar-storage
Ontario is staring down an electricity supply crunch and amid a rush to secure more power, it is plunging into the world of energy storage — a relatively unknown solution for the grid that experts say could also change energy use at home.
Beyond the sprawling nuclear plants and waterfalls that generate most of the province’s electricity sit the batteries, the underground caverns storing compressed air to generate electricity, and the spinning flywheels waiting to store energy at times of low demand and inject it back into the system when needed.
The province’s energy needs are quickly rising, with the proliferation of electric vehicles and growing Canada-U.S. collaboration on EV adoption, and increasing manufacturing demand for electricity on the horizon just as a large nuclear plant that supplies 14 per cent of Ontario’s electricity is set to be retired and other units are being refurbished.
The government is seeking to extend the life of the Pickering Nuclear Generating Station, planning an import agreement for power with Quebec, rolling out conservation programs, and — controversially — relying on more natural gas to fill the looming gap between demand and supply, amid Northern Ontario sustainability debates.
Officials with the Independent Electricity System Operator say a key advantage of natural gas generation is that it can quickly ramp up and down to meet changes in demand. Energy storage can provide that same flexibility, those in the industry say.
Energy Minister Todd Smith has directed the IESO to secure 1,500 megawatts of new natural gas capacity between 2025 and 2027, along with 2,500 megawatts of clean technology such as energy storage that can be deployed quickly, which together would be enough to power the city of Toronto.
It’s a far cry from the 54 megawatts of energy storage in use in Ontario’s grid right now.
Smith said in an interview that it’s the largest active procurement for energy storage in North America.
“The one thing that we want to ensure that we do is continue to add clean generation as much as possible, and affordable and clean generation that’s reliable,” he said.
Rupp Carriveau, director of the Environmental Energy Institute at the University of Windsor, said the timing is good.
“The space is there, the technology is there, and the willingness among private industry to respond is all there,” he said. “I know of a lot of companies that have been rubbing their hands together, looking at this potential to construct storage capacity.”
Justin Rangooni, the executive director of Energy Storage Canada, said because of the relatively tight timelines, the 2,500 megawatts is likely to be mostly lithium batteries. But there are many other ways to store energy, other than a simple battery.
“As we get to future procurements and as years pass, you’ll start to see possibly pump storage, compressed air, thermal storage, different battery chemistry,” he said.
Pump storage involves using electricity during off-peak periods to pump water into a reservoir and slowly releasing it to run a turbine and generate electricity when it’s needed. Compressed air works similarly, and old salt caverns in Goderich, Ont., are being used to store the compressed air.
In thermal storage, electricity is used to heat water when demand is low and when it’s needed, water stored in tanks can be used as heat or hot water.
Flywheels are large spinning tops that can store kinetic energy, which can be used to power a turbine and produce electricity. A flywheel facility in Minto, Ont., also installed solar panels on its roof and became the first solar storage hybrid facility in Ontario, said a top IESO official.
Katherine Sparkes, the IESO’s director of innovation, research and development, said it’s exciting, from a grid perspective.
“As we kind of look to the future and we think about gas phase out and electrification, one of the big challenges that all power systems across North America and around the world are looking at is: how do you accommodate increasing amounts of variable, renewable resources and just make better use of your grid assets,” she said.
“Hybrids, storage generation pairings, gives you that opportunity to deal with the variability of renewables, so to store electricity when the sun isn’t shining, or the wind isn’t blowing, and use it when you need it to.”
The small amount of storage already in the system provides more fine tuning of the electricity system, whereas 2,500 megawatts will be a more “foundational” part of the toolkit, said Sparkes.
But what’s currently on the grid is far from the only storage in the province. Many commercial and industrial consumers, such as large manufacturing facilities or downtown office buildings, are using storage to manage their electricity usage, relying on battery energy when prices are high.
The IESO sees that as an opportunity and has changed market rules to allow those customers to sell electricity back to the grid when needed.
As well, the IESO has its eye on the thousands of mobile batteries in electric vehicles, a trend seen in California, that shuttle people around the province every day but sit unused for much of the time.
“If we can enable those batteries to work together in aggregation, or work with other types of technologies like solar or smart building systems in a configuration, like a group of technologies, that becomes a virtual power plant,” Sparkes said.
Peak Power, a company that seeks to “make power plants obsolete,” is running a pilot project with electric vehicles in three downtown Toronto office buildings in which the car batteries can provide electricity to reduce the facility’s overall demand during peak periods using vehicle-to-building charging with bidirectional chargers.
In that model, one vehicle can earn $8,000 per year, said cofounder and chief operating officer Matthew Sachs.
“Battery energy storage will change the energy industry in the same way and for the same reasons that refrigeration changed the milk industry,” he said.
“As you had refrigeration, you could store your commodity and that changed the distribution channels of it. So I believe that energy storage is going to radically change the distribution channels of energy.”
If every home has a solar panel, an electric vehicle and a residential battery, it becomes a generating station, a decentralization that’s not only more environmentally friendly, but also relies less on “monopolized utilities,” Sachs said.
In the next decade, energy demand from electric vehicles is projected to skyrocket, making vehicle-to-grid integration increasingly relevant, and Sachs said the grid can’t grow enough to accommodate a peak demand of hundreds of thousands of vehicles being plugged in to charge at the end of the workday commute. Authorities need to be looking at more incentives such as time-of-use pricing and price signals to ensure the demand is evened out, he said.
“It’s a big risk as much as it’s a big opportunity,” he said. “If we do it wrong, it will cost us billions to fix. If we do it right, it can save us billions.”
Jack Gibbons, the chair of the Ontario Clean Air Alliance, said the provincial and federal governments need to fund and install bidirectional chargers in order to fully take advantage of electric vehicles.
Calgary Winter Energy Usage Surge highlights soaring electricity demand, added megawatt-hours, and grid reliability challenges driven by extreme cold, heating loads, and climate change, with summer air conditioning also shifting seasonal peaks.
Key Points
A spike in Calgary's power use from extreme cold, adding 22k MWh and testing reliability as heating demand rises.
✅ +22,000 MWh vs Feb 2018 amid fourth-coldest February
✅ Heating loads spike; summer A/C now drives peak demand
✅ Grid reliability monitored; more solar and green resources ahead
February was so cold in Calgary that the city used enough extra energy to power 3,400 homes for a whole year, echoing record-breaking demand in B.C. in 2021 during severe cold.
Enmax Power Corporation, the primary electricity utility in the city, says the city 's energy consumption was up 22,000 megawatt hours last month compared with Februray 2018.
"We've seen through this cold period our system has held up very well. It's been very reliable," Enmax vice-president Andre van Dijk told the Calgary Eyeopener on Friday. "You know, in the absence of a windstorm combined with cold temperatures and that sort of thing, the system has actually held up pretty well."
The past month was the fourth coldest in Calgary's history, and similar conditions have pushed all-time high demand in B.C. in recent years across the West. The average temperature for last month was –18.1 C. The long-term average for February is –5.4 C.
Watching use, predicting issues
The electricity company monitors demand and load on a daily basis, always trying to predict issues before they happen, van Dijk said, and utilities have introduced winter payment plans to help customers manage bills during prolonged cold.
One of the issues they're watching is climate change, and how extreme temperatures and weather affect both the grid's reliability, as seen when Quebec shattered consumption records during cold snaps, and the public's energy use.
The colder it gets, the higher you turn up the heat. The hotter it is, the more you use air conditioning.
He also noted that using fuels then contributes to climate change, creating a cycle.
"We are seeing variations in temperature and we've seen large weather events across the continent, across the world, in fact, that impact electrical systems, whether that's flooding, as we've experienced here, or high winds, tornadoes," van Dijk said.
"Climate change and changing weather patterns have definitely had had an impact on us as an electrical industry."
In 2012, he said, Calgary switched from using the most power during winter to using the most during summer, in large part due to air conditioning, he said.
"Temperature is a strong influencer of energy consumption and of our demand," van Dijk said.
Christmas tree lights have also become primarily LED, van Dijk said, which cuts down on a big energy draw in the winter.
He said he expects more solar and other green resources will be added into the electrical system in the future to mitigate how much the increasingly levels of energy use impact climate change, and to help moderate electricity costs in Alberta over time.
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.
Clean Energy Standard charts a federal path to decarbonize the power sector, scaling renewables, wind, solar, nuclear, and carbon capture to slash emissions, create green jobs, and reach net-zero targets amid the climate crisis.
Key Points
A federal policy to expand clean power and cut emissions with renewables, nuclear, and carbon capture toward net-zero.
✅ Mandates annual increases in clean electricity supply
✅ Includes renewables, nuclear, hydro, and carbon capture
✅ Targets rapid emissions cuts and net-zero by mid-century
The world has been put on notice. Last year, both the UN Intergovernmental Panel on Climate Change and the U.S. National Climate Assessment warned that we need to slash greenhouse gas emissions to avoid disastrous impacts of global warming. Their direct language forecasting devastating effects on our health, economics, environment, and ways of life has made even more urgent the responsibility we all have to act boldly to combat the climate crisis.
This week, we’re adding one important tool for addressing the climate crisis to the national conversation.
Together, we’re taking that bold action. The Climate reports made clear that to limit the global temperature rise and stave off devastating impacts to our climate—human-caused CO2 emissions must fall rapidly by 2030 and that we, as a global community, underscored at the Katowice climate talks, must reach net-zero emissions by the middle of the century. The Clean Energy Standard is federal legislation that offers a pathway toward decarbonizing our power sector and helping our nation accomplish a goal of net-zero emissions by the 2050s.
Under this plan, any company selling retail electricity will have a mandate to increase the amount of clean energy provided to its customers. It will incentivize clean electricity investment to put the U.S. on a sustainable path.
To deal most effectively with a crisis, all tools must be on the table. Our plan focuses solely on emissions, and there is a place for all technologies that can put us on the path to net zero. That will mean drastic increases in wind and solar energy for sure, as states like California pursue a 100% carbon-free electricity mandate to accelerate deployment, but nuclear power, hydro power, and fossil fuels with carbon capture and storage all have important roles to play.
We’re doing this because the science is clear – tackling our climate crisis requires serious and rapid action to control greenhouse gas emissions, and the push for decarbonization is irreversible according to many. Inaction on the climate crisis puts our families at risk, and we’re not wasting any time. This is also an opportunity to create good-paying green jobs that can last generations and uplift the middle class.
We are doing this for the environment, but also for jobs and economic competitiveness. The green economy is the future and we’re ready to see it grow, with states like New York advancing a Green New Deal that drives innovation. The United States can lead, or we can follow, and we want our nation to lead.
And, because as a New Mexican and a Minnesotan, we know that the impacts of climate change go far beyond the headlines and political discourse. It means devastation within tamarack forests and an increase in deadly fires. It means hotter summers and shorter winters with extreme temperature swings throughout the year. It means devastating flash floods with increasingly intense rain. It’s impacting our pocketbooks when farmers and small businesses who work the land in rural communities are unable to make ends meet.
States across the country are already acting to combat the climate crisis – including Minnesota's 2050 carbon-free electricity plan and New Mexico. But in order to truly address climate change, we have to be in this together as Americans. If the problem is far-reaching, our solutions must be equally as holistic.
It's why we've worked with green groups and activists, unions, and communities across the country - from urban to rural - to create a solution that understands the different starting points communities face in reaching net zero emissions, but doesn't shrink from the absolute need to reach that standard.
There is not one solution to climate change – it will take a collective group of individuals prepared to boldly act. And we are ready to take on that fight.
In Congress, we have formed the House Select Committee on the Climate Crisis and the Senate Democrats’ Special Committee on the Climate Crisis to hear from everyday Americans how climate change is affecting them – and how we can come together to find solutions that build on the historic climate deal passed this year. We have heard the stories of young people worried about their futures. And we realize there is a sense of urgency to act.
Over the coming weeks and months, we will be building support from communities across the country to make this plan a reality. We will continue working with stakeholders to ensure every voice is heard. Most importantly, we will continue listening to you and your communities.
Tesla Solar and Powerwall Discount offers a ~10% installation price cut amid PG&E blackouts, helping California homeowners with solar panels, battery storage, and backup power, while supporting renewable energy and resilient Supercharger infrastructure.
Key Points
A ~10% installation discount on Tesla solar panels and Powerwall batteries to boost backup power during PG&E blackouts.
✅ ~10% off installation for solar plus Powerwall
✅ Helps during PG&E shutoffs and wildfire mitigation
✅ Supports resilience, backup power, and EV charging
Pacific Gas & Electric’s (PG&E) shutoff of electric supply to residents in California’s Bay Area has caught the attention of Tesla and SpaceX CEO Elon Musk, who, while highlighting a huge future for Tesla Energy in coming years, has announced that he would be offering a price reduction of approximately 10% for a solar panel and Tesla Powerwall battery installation. The discount will be available to anyone interested in powering their homes with solar energy, not just the 800,000 affected homes in the Bay Area.
After initially tweeting a link to Tesla’s Solar page on Tesla.com, Musk added that he would be offering a “~10% price reduction” in installation price for solar panels and Powerwall batteries for anyone, as California explores EVs for grid stability during emergencies, including those who have lost power in response to PG&E’s power shutoff. The blackout induced by the California-based power company is a part of an effort to reduce the possibility of wildfires. PG&E lines were the cause of multiple fires in the past, so the company is taking every necessary precaution to reduce the probability of its lines causing another fire in the future.
Tesla Solar recently offered a subscription program that would allow homeowners to lease panels for a fraction of the cost. The service is available to both residential and commercial customers, and costs as little as $45 a month in some states, particularly appealing in California where EV sales top 20% recently. The option to lease solar panels carries no long-term contracts that would tie down customers to a lengthy commitment.
Wildfires have always been an issue in California. Currently, fires are ripping through Los Angeles county, presumably caused by the winds of the Autumn season. The effort to reduce the environmental impact of forest fires in the state has been increasingly more prevalent over the years. But 2019 is a different story, underscoring that California may need a much bigger grid to support electrification, considering the previous year was noted as the deadliest wildfire season in California’s history. Over 8,500 fires destroyed over 1.89 million acres of land burned due to fires, causing the California Department of Forestry and Fire Protection to spend $432 million through the end of August 2018, according to the Associated Press.
In reaction to the news of the power shutoffs, Tesla added words of advice to vehicle affected owners on its app. The company posted a message encouraging drivers to keep their vehicles charged to 100% and highlighted that EVs can power homes for up to three days during outages, in order to prevent interruptions in driving. Those who are driving ICE vehicles are feeling the effects of the blackout too, as gas stations in California’s affected region have begun to shut down. Musk also tweeted that he would be installing Tesla Powerpacks at all Supercharger stations in the affected region, a move that can help ease strain on state power grids during outages, in order to allow owners to charge their vehicles.
In addition to the efforts that Tesla has already put into place, Musk plans to transition all Supercharger stations to solar power as soon as possible. But the sunny climate of California offers residents a great opportunity to move from gas and electric, even as some warn of a looming green car wreck in the state, to a more eco-friendly, sun-powered option. Tesla solar will completely eliminate power blackouts that are used to control wildfires in California.
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.
