Nearly nine months after a devastating earthquake and tsunami caused a meltdown at the Fukushima Daiichi nuclear power plant in Japan, the aftershocks are being felt in Saint John at licence renewal hearings for the Point Lepreau nuclear generating station.
On the first of two days of public hearings, seismic safety played a central role as NB Power applies for approval to reload fuel and restart the refurbished Point Lepreau plant some time next fall.
Canadian Nuclear Safety Commission president and CEO Michael Binder began the hearings at the Delta Brunswick Hotel on Thursday by acknowledging the shadow the Japanese disaster has cast over nuclear safety around the world.
"The triple catastrophe in Japan will have a bearing on this hearing," he said.
Binder added that the economic impact of the facility will not play a role in the decision of the politically independent commission, which is expected to come in six weeks.
He said the health and safety of the public and environmental considerations are the major factors as to whether NB Power will be given permission to restart the plant after more than four years of refurbishment work.
Officials with NB Power, emergency preparedness in the province and a seismologist from Natural Resources Canada reassured the public that Point Lepreau was safe, and not at high risk of a meltdown caused by an earthquake.
Wade Parker, the station director at Point Lepreau, said earthquakes were considered in the original design when the plant was built in the late 1970s, and described it as "seismically robust."
The refurbishment, originally scheduled to take 18 months and cost $1.4 billion, has suffered from several delays, but it is expected to finally be finished next fall and $1 billion over budget.
NB Power estimates that the refurbishment will extend the life of the plant for 25 to 30 years after it returns to service.
John Adams, an NRC seismologist, said major earthquakes in Eastern Canada are extremely rare, with only minor quakes rocking the province from time to time.
He said a 6.2 magnitude quake would be of concern to Point Lepreau, but he said according to measured and historical data, no temblors that size have been felt in this part of the country in the last several hundred years.
The largest quake ever measured in Eastern Canada was in the Charlevoix region north of Quebec City, which has experienced two quakes over magnitude 6.0, the last more than 80 years ago.
Nuclear plants in Canada are expected to be prepared for a 1 in 10,000 year quake, making Point Lepreau an extremely safe location for a facility, since New Brunswick is an area of extremely low seismic activity.
One voice of dissent came from Paula Tippett from the Saint John chapter of the Council of Canadians.
Her group opposes the restart of Point Lepreau for several reasons, including environmental concerns. However Tippett also cited seismic activity brought about by hydro-fracking in the exploration for natural gas in the province.
"We want to make sure studies into earthquake activity around injection wells are looked at closely," she said.
Adams said earthquakes from hydro-fracking are believed to be minor, and only occur near where exploration is taking place.
Current exploration leases show injection wells, if used, would likely be drilled no nearer than 70 kilometres away, in Quispamsis, too far away to cause any issues, said Adams.
Raj Jaitly, a consultant with CANDU Energy who also worked with the NB Power safety group when Point Lepreau was first brought online in 1983, said the plant is ahead of the rest of the nuclear facilities in the country.
"It is the first to conduct a complete seismic study in Canada," he said.
Jaitly said the lengthy refurbishment of the plant probably worked to the advantage of safety planners because as they upgraded systems, lessons learned from the Japan disaster could then be implemented into the new Point Lepreau design.
"People who know nuclear energy are not concerned," he said. "There are several levels of defence that will prevent a major disaster in this plant."
Rod Eagles, deputy chief nuclear officer with NB Power and the refurbishment director, said the nuclear industry is very progressive when it comes to safety. And he said the work at Point Lepreau will provide New Brunswick with safe electricity for several more decades when it goes back online.
"The refurbishment allowed us to find opportunities to make the plant as safe as possible," he said. "And safety became even more prominent post-Fukushima."
Nuclear Energy Growth accelerates as nations pursue decarbonization, complement renewables, displace coal, and ensure grid reliability with firm, low-carbon baseload, benefiting from standardized builds, lower cost of capital, and learning-curve cost reductions.
Key Points
Expansion of nuclear capacity to cut CO2, complement renewables, replace coal, and stabilize grids at low-carbon cost.
✅ Complements renewables; displaces coal for faster decarbonization
✅ Cuts system costs via standardization and lower cost of capital
✅ Provides firm, low-carbon baseload and grid reliability
By Kirill Komarov, Chairman, World Nuclear Association.
As Europe and the wider world begins to wake up to the need to cut emissions, Dr Kirill Komarov argues that tackling climate change will see the use of nuclear energy grow in the coming years, not as a competitor to renewables but as a competitor to coal.
The nuclear industry keeps making headlines and spurring debates on energy policy, including the green industrial revolution agenda in several countries. With each new build project, the detractors of nuclear power crowd the bandwagon to portray renewables as an easy and cheap alternative to ‘increasingly costly’ nuclear: if solar and wind are virtually free why bother splitting atoms?
Yet, paradoxically as it may seem, if we are serious about policy response to climate change, nuclear energy is seeing an atomic energy resurgence in the coming decade or two.
Growth has already started to pick up with about 3.1 GW new capacity added in the first half of 2018 in Russia and China while, at the very least, 4GW more to be completed by the end of the year – more than doubling the capacity additions in 2017.
In 2019 new connections to the grid would exceed 10GW by a significant margin.
If nuclear is in decline, why then do China, India, Russia and other countries keep building nuclear power plants?
To begin with, the issue of cost, argued by those opposed to nuclear, is in fact largely a bogus one, which does not make a fully rounded like for like comparison.
It is true that the latest generation reactors, especially those under construction in the US and Western Europe, have encountered significant construction delays and cost overruns.
But the main, and often the only, reason for that is the ‘first-of-a-kind’ nature of those projects.
If you build something for the first time, be it nuclear, wind or solar, it is expensive. Experience shows that with series build, standardised construction economies of scale and the learning curve from multiple projects, costs come down by around one-third; and this is exactly what is already happening in some parts of the world.
Furthermore, those first-of-a-kind projects were forced to be financed 100% privately and investors had to bear all political risks. It sent the cost of capital soaring, increasing at one stroke the final electricity price by about one third.
While, according to the International Energy Agency, at 3% cost of capital rate, nuclear is the cheapest source of energy: on average 1% increase adds about US$6-7 per MWh to the final price.
When it comes to solar and wind, the truth, inconvenient for those cherishing the fantasy of a world relying 100% on renewables, is that the ‘plummeting prices’ (which, by the way, haven’t changed much over the last three years, reaching a plateau) do not factor in so-called system and balancing costs associated with the need to smooth the intermittency of renewables.
Put simply, the fact the sun doesn’t shine at night and wind doesn’t blow all the time means wind and solar generation needs to be backed up.
According to a study by the Potsdam Institute for Climate Impact Research, integration of intermittent renewables into the grid is estimated in some cases to be as expensive as power generation itself.
Delivering the highest possible renewable content means customers’ bills will have to cover: renewable generation costs, energy storage solutions, major grid updates and interconnections investment, as well as gas or coal peaking power plants or ‘peakers’, which work only from time to time when needed to back up wind and solar.
The expected cost for kWh for peakers, according to investment bank Lazard is about twice that of conventional power plants due to much lower capacity factors.
Despite exceptionally low fossil fuel prices, peaking natural gas generation had an eye-watering cost of $156-210 per MWh in 2017 while electricity storage, replacing ‘peakers’, would imply an extra cost of $186-413 per MWh.
Burning fossil fuels is cheaper but comes with a great deal of environmental concern and extensive use of coal would make net-zero emissions targets all but unattainable.
So, contrary to some claims, nuclear does not compete with renewables. Moreover, a recent study by the MIT Energy Initiative showed, most convincingly, that renewables and load following advanced nuclear are complementary.
Nuclear competes with coal. Phasing out coal is crucial to fighting climate change. Putting off decisions to build new nuclear capacities while increasing the share of intermittent renewables makes coal indispensable and extends its life.
Scientists at the Brattle group, a consultancy, argue that “since CO2 emissions persist for many years in the atmosphere, near-term emission reductions are more helpful for climate protection than later ones”.
The longer we hesitate with new nuclear build the more difficult it becomes to save the Earth.
Nuclear power accounta for about one-tenth of global electricity production, but as much as one-third of generation from low-carbon sources. 1GWe of installed nuclear capacity prevents emissions of 4-7 million metric tons of CO2 emissions per year, depending on the region.
The International Energy Agency (IEA) estimates that in order to limit the average global temperature increase to 2°C and still meet global power demand, we need to connect to the grid at least 20GW of new nuclear energy each year.
The World Nuclear Association (WNA) sets the target even higher with the total of 1,000 GWe by 2050, or about 10 GWe per year before 2020; 25 GWe per year from 2021 to 2025; and on average 33 GWe from 2026 to 2050.
Regulatory and political challenges in the West have made life for nuclear businesses in the US and in Europe's nuclear sector very difficult, driving many of them to the edge of insolvency; but in the rest of the world nuclear energy is thriving.
Nuclear vendors and utilities post healthy profits and invest heavily in next-gen nuclear innovation and expansion. The BRICS countries are leading the way, taking over the initiative in the global climate agenda. From their perspective, it’s the opposite of decline.
Dr Kirill Komarov is first deputy CEO of Russian state nuclear energy operator Rosatom and chairman of the World Nuclear Association.
Hydro One Avista Takeover faces Washington UTC scrutiny as regulators deny approval; companies plan a reconsideration petition, citing acquisition terms, governance concerns, merger risks, EPS dilution, and balance sheet impacts across regulated utility operations.
Key Points
A $6.7B bid by Hydro One to buy Avista, denied by Washington UTC on governance risk, under reconsideration petition.
✅ UTC denied over potential provincial interference.
✅ Petition for reconsideration due by Dec. 17.
✅ Deal seen diluting EPS, weakening balance sheet.
Hydro One Ltd. and Avista Corp. say they plan to formally request that the Washington Utilities and Transportation Commission reconsider its order last week denying approval of the $6.7-billion takeover, which previously received U.S. antitrust clearance from federal regulators, of the U.S.-based energy utility.
The two companies say they will file a petition no later than Dec. 17 but haven't indicated on what grounds they are making the request, even as investor concerns about Hydro One persist.
Under Washington State law, the UTC has 20 days to consider the petition, otherwise it is deemed to be denied.
If it reconsiders its decision, the UTC can modify the prior order or take any actions it deems appropriate, similar to provincial rulings such as the OEB decision on Hydro One's first combined T&D rates, including extending deliberations.
Washington State regulators said they would not allow Ontario's largest utility to buy Avista for fear the provincial government, which owns 47 per cent of Hydro One's shares and recently prompted a CEO and board exit at the utility, might meddle in Avista's operations.
Hydro One's shares have risen since the order because the deal, announced in July 2017, would have eroded earnings per share and weakened Hydro One's balance sheet, according to analysts, even as the company reported a one-time-boosted Q2 profit earlier this year.
Twin States Clean Energy Link connects New England to Hydro-Quebec via a 1,200 MW transmission line, DOE-backed capacity, underground segments, existing corridors, boosting renewable energy reliability across Vermont and New Hampshire with cross-border grid flexibility.
Key Points
DOE-backed 1,200 MW line linking Hydro-Quebec to New England, adding clean capacity with underground routes.
✅ 1,200 MW cross-border capacity for the New England grid
✅ Uses existing corridors; underground in VT and northern NH
✅ DOE capacity contract lowers risk and spurs investment
A proposal to build a new transmission line to connect New England with Canadian hydropower is one step closer to reality.
The U.S. Department of Energy announced Monday that it has selected the Twin States Clean Energy Link as one of three transmission projects that will be part of its $1.3 billion cross-border transmission initiative to add capacity to the grid.
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Twin States is a proposal from National Grid, a utility company that serves Massachusetts, New York, and Rhode Island, and also owns transmission in England and Wales as the region advances projects like the Scotland-to-England subsea link that expand renewable flows, and the non-profit Citizens Energy Corporation.
The transmission line would connect New England with power from Hydro-Quebec, moving into the United States from Canada in Northern Vermont and crossing into New Hampshire near Dalton. It would run through parts of Grafton, Merrimack, and Hillsborough counties, routing through a substation in Dunbarton and ending at a proposed new substation in Londonderry. (Here's a map of the Twin States proposal.)
The federal funding will allow the U.S. Department of Energy to purchase capacity on the planned transmission line, which officials say reduces the risk for other investors and can help encourage others to purchase capacity.
The project has gotten support from local officials in Vermont and New Hampshire, but there are still hurdles to cross. The contract negotiation process is beginning, National Grid said, and the proposal still needs approvals from regulators before construction could begin.
First Nations communities in Canada have opposed transmission lines connecting Hydro-Quebec with New England in the past, and the company has faced scrutiny from environmental groups.
What would Twin States look like? Transmission projects, like the failed Northern Pass proposal, have been controversial in New England, though the Great Northern Transmission Line progressed in Minnesota.
But Reihaneh Irani-Famili, vice president of capital delivery, project management and construction at National Grid, said this one is different because the developers listened to community concerns before planning the project.
“They did not want new corridors of infrastructure, so we made sure that we're using existing right of way,” she said. “They did not want the visual impact and some of the newer corridors of infrastructure, we're making sure we're undergrounding portions of the line.”
In Vermont and northern New Hampshire, the transmission lines would be buried underground along state roads. South of Littleton, they would be located within existing transmission corridors.
The developers say the lines could provide 1,200 megawatts of transmission capacity. The project would have the ability to carry electricity from hydro facilities in Quebec to New England, and would also be able to bring electricity from New England into Quebec, a step toward broader macrogrid connectivity across regions.
“Those hydro dams become giant green batteries for the region, and they hold that water until we need the electrons,” Irani-Famili said. “So if you think about our energy system not as one that sees borders, but one that sees resources, this is connecting the Quebec resources to the New England resources and helping all of us get into that cleaner energy future with a lot less build than we otherwise would have.”
Irani-Famili says the transmission line could help facilitate more clean energy resources like offshore wind coming online. In a report released last week by New Hampshire’s Department of Energy, authors said importing Canadian hydropower could be one of the most cost-effective ways to move away from fossil fuels on the electric grid.
National Grid estimates the project will help save energy customers $8.3 billion in its first 12 years. The developers are constructing a $260 million “community benefits plan” that would take some profits from the transmission line and give that money back to communities that host the transmission lines and environmental justice communities in New England.
NB Power and Hydro-Québec Electricity Agreements expand clean hydroelectric exports, support Mactaquac dam refurbishment, add grid interconnections, and advance decarbonization, climate goals, reliability, and transmission capacity across Atlantic Canada and U.S. markets through 2040.
Key Points
Deals for hydro exports, Mactaquac upgrades, and new interconnections to improve reliability and cut emissions.
✅ 47 TWh to NB by 2040 over existing transmission lines
✅ HQ expertise to address Mactaquac concrete swelling
✅ Talks on new interconnections for Atlantic and U.S. exports
NB Power and Hydro-Quebec have signed three deals that will see Quebec sell more electricity to New Brunswick and provide help with the refurbishment of the Mactaquac hydroelectric generating station.
Under the first agreement, Hydro-Quebec will export 47 terawatt hours of electricity to New Brunswick between now and 2040 over existing power lines — expanding on an agreement in place since 2012 and on related regional agreements such as the Churchill Falls deal in Newfoundland and Labrador.
The second deal will see Hydro-Quebec share expertise for part of the refurbishment of the Mactaquac dam to extend the useful life of the generating station until at least 2068, when the 670 megawatt facility on the St. John River will be 100 years old.
Since the 1980s, concrete portions of the facility have been affected by a chemical reaction that causes the concrete to swell and crack.
Hydro-Quebec has been dealing with the same problem, and has developed expertise in addressing the issue.
“This is why we have signed a technical collaboration agreement between Hydro-Quebec and us for part of the refurbishment of the Mactaquac generating station,” NB Power president Gaetan Thomas said Friday.
Eric Martel, CEO of Hydro-Quebec, said hydroelectric plants provide long-term clean power that’s important in the fight against climate change as the province has ruled out nuclear power for now.
“We understand how important it is to ensure the long term sustainability of these facilities and we are happy to share the expertise that Hydro-Quebec has acquired over the years,” Martel said.
The refurbishment of the Mactaquac generating station is expected to cost between $2.9 billion and $3.5 billion. Once the work begins, each of the facility’s six generators will have to be taken offline for months at a time, and Thomas said that’s where the increased power from Quebec, supported by Hydro-Quebec's capacity expansion in recent years, will come into use.
He expects the power could cost about $100 million per year but will be much cheaper than other sources.
The third agreement calls for talks to begin for the construction of additional power connections between Quebec and New Brunswick to increase exports to Atlantic Canada and the United States, where transmission constraints have limited incremental deliveries in recent years.
“Building new interconnections and allowing for increased power transfer between our systems could be mutually beneficial, even as historic tensions in Newfoundland and Labrador linger. More than ever, we are looking to the future,” Martel said.
“Partnering will permit us to seize new business opportunities together and pool our effort to support de-carbonization, including Hydro-Quebec's non-fossil strategy that is now underway, and fight against climate change, both here and in our neighbourhood market,” he said.
Methane Hydrate CO2 Sequestration uses carbon capture and nitrogen injection to swap gases in seafloor hydrates along the Gulf of Mexico, releasing methane for electricity while storing CO2, according to new simulation research.
Key Points
A method injecting CO2 and nitrogen into hydrates to store CO2 while releasing methane for power.
✅ Nitrogen aids CO2-methane swap in hydrate cages, speeding sequestration
✅ Gulf Coast proximity to emitters lowers transport and power costs
✅ Revenue from methane electricity could offset carbon capture
The world is quickly realizing it may need to actively pull carbon dioxide out of the atmosphere to stave off the ill effects of climate change. Scientists and engineers have proposed various carbon capture techniques, but most would be extremely expensive—without generating any revenue. No one wants to foot the bill.
One method explored in the past decade might now be a step closer to becoming practical, as a result of a new computer simulation study. The process would involve pumping airborne CO2 down into methane hydrates—large deposits of icy water and methane right under the seafloor, beneath water 500 to 1,000 feet deep—where the gas would be permanently stored, or sequestered. The incoming CO2 would push out the methane, which would be piped to the surface and burned to generate electricity, whether sold locally or via exporters like Hydro-Qu e9bec to help defray costs, to power the sequestration operation or to bring in revenue to pay for it.
Many methane hydrate deposits exist along the Gulf of Mexico shore and other coastlines. Large power plants and industrial facilities that emit CO2 also line the Gulf Coast, where EPA power plant rules could shape deployment, so one option would be to capture the gas directly from nearby smokestacks, keeping it out of the atmosphere to begin with. And the plants and industries themselves could provide a ready market for the electricity generated.
A methane hydrate is a deposit of frozen, latticelike water molecules. The loose network has many empty, molecular-size pores, or “cages,” that can trap methane molecules rising through cracks in the rock below. The computer simulation shows that pushing out the methane with CO2 is greatly enhanced if a high concentration of nitrogen is also injected, and that the gas swap is a two-step process. (Nitrogen is readily available anywhere, because it makes up 78 percent of the earth’s atmosphere.) In one step the nitrogen enters the cages; this destabilizes the trapped methane, which escapes the cages. In a separate step, the nitrogen helps CO2 crystallize in the emptied cages. The disturbed system “tries to reach a new equilibrium; the balance goes to more CO2 and less methane,” says Kris Darnell, who led the study, published June 27 in the journal Water Resources Research. Darnell recently joined the petroleum engineering software company Novi Labs as a data scientist, after receiving his Ph.D. in geoscience from the University of Texas, where the study was done.
A group of labs, universities and companies had tested the technique in a limited feasibility trial in 2012 on Alaska’s North Slope, where methane hydrates form in sandstone under deep permafrost. They sent CO2 and nitrogen down a pipe into the hydrate. Some CO2 ended up being stored, and some methane was released up the same pipe. That is as far as the experiment was intended to go. “It’s good that Kris [Darnell] could make headway” from that experience, says Ray Boswell at the U.S. Department of Energy’s National Energy Technology Laboratory, who was one of the Alaska experiment leaders but was not involved in the new study. The new simulation also showed that the swap of CO2 for methane is likely to be much more extensive—and to happen quicker—if CO2 enters at one end of a hydrate deposit and methane is collected at a distant end.
The technique is somewhat similar in concept to one investigated in the early 2010s by Steven Bryant and others at the University of Texas. In addition to numerous methane hydrate deposits, the Gulf Coast has large pools of hot, salty brine in sedimentary rock under the coastline. In this system, pumps would send CO2 down into one end of a deposit, which would force brine into a pipe that is placed at the other end and leads back to the surface. There the hot brine would flow through a heat exchanger, where heat could be extracted and used for industrial processes or to generate electricity, supporting projects such as electrified LNG in some markets. The upwelling brine also contains some methane that could be siphoned off and burned. The CO2 dissolves into the underground brine, becomes dense and sinks further belowground, where it theoretically remains.
Either system faces big practical challenges, and building shared CO2 storage hubs to aggregate captured gas is still evolving. One is creating a concentrated flow of CO2; the gas makes up only .04 percent of air, and roughly 10 percent of the smokestack emission from a typical power plant or industrial facility. If an efficient methane hydrate or brine system requires an input that is 90 percent CO2, for example, concentrating the gas will require an enormous amount of energy—making the process very expensive. “But if you only need a 50 percent concentration, that could be more attractive,” says Bryant, who is now a professor of chemical and petroleum engineering at the University of Calgary. “You have to reduce the [CO2] capture cost.”
Another major challenge for the methane hydrate approach is how to collect the freed methane, which could simply seep out of the deposit through numerous cracks and in all directions. “What kind of well [and pipe] structure would you use to grab it?” Bryant asks.
Given these realities, there is little economic incentive today to use methane hydrates for sequestering CO2. But as concentrations rise in the atmosphere and the planet warms further, and as calls for an electric planet intensify, systems that could capture the gas and also provide energy or revenue to run the process might become more viable than techniques that simply pull CO2 from the air and lock it away, offering nothing in return.
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.
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