China's Ministry of Commerce said it would consider a U.S. request for consultations over its support for wind power technology, while defending its actions as in keeping with global trade rules.
The United States accused China of illegally subsidizing production of wind power equipment and asked for talks at the World Trade Organization, the first step in filing a trade case.
"China will conscientiously study the U.S. request for consultations, and will deal with this in accordance with WTO dispute settlement rules, while retaining our corresponding rights," the Chinese Commerce Ministry said in its first reaction to the U.S. move.
The statement on the Ministry's website said China's wind power policies were "in keeping with WTO rules" and were also good for the environment.
By the midday break, shares in Chinese wind turbine makers and wind power generators that have interests in the United States fell.
China High Speed Transmission Equipment Group was down 1.9 percent, Xinjiang Goldwind Science and Technology fell 0.8 percent and China Longyuan Power Group Corp slipped 2 percent, trailing Hong Kong's benchmark Hang Seng Index, which was up 0.19 percent.
The Ministry's comments were a relatively tempered initial response to the U.S. complaint, which has been made ahead of a January visit to Washington by Chinese President Hu Jintao.
The U.S. Trade Representative says that Chinese manufacturers of wind turbines and components may have received several hundred million dollars in government grants that violate trade rules by requiring Chinese manufacturers to use only Chinese-made parts and components.
U.S. Trade Representative Ron Kirk said in a statement that "import substitution subsidies are particularly harmful and inherently trade distorting," noting that they were operating as a barrier to U.S. exports to China.
By asking for WTO talks, the U.S. begins a 60-day period for the two countries to resolve the disagreement through consultation. If those efforts fail, the U.S. could ask for a WTO dispute settlement panel to hear its complaint.
China has said its new five-year plan for renewable energy will include pledges to boost wind power capacity to 90 gigawatts.
That target is to be met in part by the construction of seven 10 GW wind power projects, five of which are expected to be completed before 2016.
China has been doubling installed wind power capacity every year for the past several years. In 2009, it became the third largest wind energy provider worldwide — behind the United States and Germany — with installed capacity reaching 20GW.
The government's mandate that local power authorities buy the output from wind projects at competitive prices has helped create that boom.
Cold-Climate Heat Pumps deliver efficient heating and cooling for Northern B.C. Net Zero Ready homes, with air-source Mitsubishi H2i systems, triple-pane windows, blower door ACH 0.8, BC Hydro rebates, and CleanBC incentives.
Key Points
Electric air-source systems that heat and cool in subzero climates, cutting emissions and lowering energy costs.
✅ Net Zero Ready, Step Code 5, ACH 0.8 airtightness
✅ Operate efficiently to about -28 C with backup heat
✅ Eligible for BC Hydro and CleanBC rebates
Heat pump provides heating, cooling in northern B.C. home It's a tradition at Vanderhoof-based Northern Homecraft that, on the day of the blower door test for a just-completed home, everyone who worked on the build gathers to watch it happen. And in the spring of 2021, on a dazzling piece of land overlooking the mouth of the Stuart River near Fort St. James, that day was a cause for celebration.
A new 3,400-square foot home subjected to the blower door test – a diagnostic tool to determine how much air is entering or escaping from a home – was rated as having just .8 air changes per hour (ACH). That helps make it a Net Zero Ready home, and BC Energy Code Step 5 compliant. That means it would take about a third of the amount of energy to heat the home compared to a typical similar-sized home in B.C. today.
From an energy-efficiency perspective, this is a home whose evident beauty is anything but skin deep.
"The home has lot of square footage of finished living space, and it also has a lot of glazing," says Northern Homecraft owner Shay Bulmer, referring to the home's large windows. "We had a lot of window space to deal with, as well as large vaulted open areas where you can only achieve so much additional insulation. There were a few things that the home had going against it as far as performance goes. There were challenges in keeping it comfortable year-round."
Well-insulated home ideal for heat pump option Most homes in colder areas of B.C. lean on gas-fueled heating systems to deal with the often long, chilly winters. But with the arrival of cold climate heat pumps capable of providing heat efficiently when temperatures dip as low as -30°C, there's now a clean option for those homes, and using more electricity for heat is gaining support in the North as well.
Heat pumps are an increasingly popular option, both for new and existing homes, because they avoid carbon emissions associated with fossil use while also offering summer cooling, even as record-high electricity demand in Yukon underscores the need for efficient systems.
The Fort St. James home, which was built with premium insulation, airtightness and energy efficiency in mind, made the decision to opt for a heat pump even easier. Still, the heat pump option took the home's owners Dexter and Cheryl Hodder by surprise. While their focus was on designing a home that took full advantage of views down to the river, the couple was under the distinct impression that heat pumps couldn't cut it in the chilly north.
"I wasn't really considering a heat pump, which I thought was only a good solution in a moderate climate," says Dexter, who as director of research and education for the John Prince Research Forest, studies wildlife and forestry interactions in north central B.C. "The specs on the heat pump indicate it would work down to -28°C, and I was skeptical of that. But it worked exactly to spec. It almost seems ridiculous to generate heat from outside air at those low temperatures, but it does."
Getting it right with support and rebates Northern Homecraft took advantage of BC Hydro's Mechanical System Design Pilot program to ensure proper heat pump system design, installation, and verification for the home were applied, and with BC Hydro's first call for power in 15 years driven by electrification, the team prioritized efficient load management.
Based on the home's specific location, size, and performance targets, they installed a ducted Mitsubishi H2I air-source heat pump system. Windows are triple pane, double coated, and a central feature of the home, while insulation specifications were R-40 deep frame insulation in the exterior walls, R-80 insulation in the attic, and R-40 insulation in the vaulted ceilings.
The combination of the year-round benefits of heat pumps, their role in reducing fossil fuel emissions, and the availability of rebates, is making the systems increasingly attractive in B.C., especially as two new BC generating stations were recently commissioned to expand clean supply.
BC Hydro offers home renovation rebates of up to $10,000 for energy-efficient upgrades to existing homes. Rebates are available for windows and doors, insulation, heat pumps, and heat pump hot water heaters. In partnership with CleanBC, rebates of up to $11,000 are also available – when combined with the federal Greener Homes program – for those switching from fossil fuel heating to an electric heat pump.
'Heat dome' pushes summer highs to 40°C Cooling wasn't really a consideration for Dexter and Cheryl when they were living in a smaller bungalow shaded by trees. But they knew that with the big windows, vaulted ceiling in the living room, and an upstairs bedroom in the new home, there may come a time when they needed air conditioning.
That day arrived shortly after the home was built, as the infamous "heat dome" settled on B.C. and drove temperatures at Fort St. James to a dizzying 40°C.
"It was disgustingly hot, and I don't care if I never see that again here," says Hodder, with a laugh. "But the heat pump maintained the house really nicely throughout, at about 22 degrees. The whole house stayed cool. We just had to close the door to the upper bedroom so it wasn't really heating up during the day."
Hodder says he had to work with the heat pump manufacturer Mitsubishi a couple times over that first year to fix a few issues with the system's controls. But he's confident that the building's tight and well-insulated envelope, and the heat pump's backup electric heat that kicks in when temperatures dip below -28°C, will make it the system-for-all-seasons it was designed to be.
Even with the use of supplemental electric heating during the record chill of December-January, the home's energy costs weren't much higher than the mid-winter energy bills they used to pay in the couple's smaller bungalow that relied on a combination of gas-fired in-floor heating and electric baseboards, as gas-for-electricity swaps are being explored elsewhere.
Fort St. James is a former fur trading post located northwest of Prince George and a short drive north of Vanderhoof. Winters are cold and snowy, with average daily low temperatures in December and January of around -14°C.
"During the summer and into the fall, we were paying well less than $100 a month," says Hodder, looking back at electricity bills over the first year in the home. "And that's everything. We're only electric here, and we also had both of us working from home all last year."
Word of mouth making heat pumps popular in Fort St. James While the size of the home presented new challenges for the builders, it's one of five Net Zero Ready or Net Zero homes – all equipped with some form of heat pump – that Northern Homecraft has built in Fort St. James, even as debates about going nuclear for electricity continue in B.C.
The smallest of the homes is a two-bedroom, one-bathroom home that's just under 900 square feet. Northern Homecraft may be based in Vanderhoof, but it's the much smaller town of Fort St. James where they're making their mark with super-efficient homes. Net Zero Ready homes are up to 80% more efficient than the standard building code, and become Net Zero once renewable energy generation – usually in the form of photovoltaic solar – is installed, and programs like switching 5,000 homes to geothermal show the broader momentum for clean heating.
"We were pretty proud that the first home we built in Fort St. James was the first single family Net Zero Ready home built in B.C.," says Northern Homecraft's Bulmer. "And I think it's kind of caught on in a smaller community where everyone talks to everyone."
Maritime Link HVDC Transmission connects Newfoundland and Nova Scotia to the North American grid, enabling renewable energy imports, subsea cable interconnection, Muskrat Falls hydro power delivery, and lower carbon emissions across Atlantic Canada.
Key Points
A 500 MW HVDC intertie linking Newfoundland and Nova Scotia to deliver Muskrat Falls hydro power.
✅ 500 MW capacity using twin 170 km subsea HVDC cables
✅ Interconnects Newfoundland and Nova Scotia to the North American grid
✅ Enables Muskrat Falls hydro imports, cutting CO2 and costs
For the first time, electricity has been sent between Newfoundland and Nova Scotia through the new Maritime Link.
The 500-megawatt transmission line — which connects Newfoundland to the North American energy grid for the first time and echoes projects like the New England Clean Power Link underway — was tested Friday.
"This changes not only the energy options for Newfoundland and Labrador but also for Nova Scotia and Atlantic Canada," said Rick Janega, the CEO of Emera Newfoundland and Labrador, which owns the link.
"It's an historic event in our eyes, one that transforms the electricity system in our region forever."
'On time and on budget'
It will eventually carry power from the Muskrat Falls hydro project in Labrador, where construction is running two years behind schedule and $4 billion over budget, a context in which the Manitoba Hydro line to Minnesota has also faced delay, to Nova Scotia consumers. It was supposed to start producing power later this year, but the new deadline is 2020 at the earliest.
The project includes two 170-kilometre subsea cables across the Cabot Strait between Cape Ray in southwestern Newfoundland and Point Aconi in Cape Breton.
The two cables, each the width of a two-litre pop bottle, can carry 250 megawatts of high voltage direct current, and rest on the ocean floor at depths up to 470 metres.
This reel of cable arrived in St. John's back in April aboard the Norwegian vessel Nexans Skagerrak, after the first power cable reached Nova Scotia earlier in the project. (Submitted by Emera NL)
The Maritime Link also includes almost 50 kilometres of overland transmission in Nova Scotia and more than 300 kilometres of overland transmission in Newfoundland, paralleling milestones on Site C transmission work in British Columbia.
The link won't go into commercial operation until January 1.
Janega said the $1.6-billion project is on time and on budget.
"We're very pleased to be in a position to be able to say that after seven years of working on this. It's quite an accomplishment," he said.
This Norwegian vessel was used to transport the 5,500 tonne subsea cable. (Submitted by Emera NL)
Once in service, the link will improve electrical interconnections between the Atlantic provinces, aligning with climate adaptation guidance for Canadian utilities.
"For Nova Scotia it will allow it to achieve its 40 per cent renewable energy target in 2020. For Newfoundland it will allow them to shut off the Holyrood generating station, in fact using the Maritime Link in advance of the balance of the project coming into service," Janega said.
Karen Hutt, president and CEO of Nova Scotia Power, which is owned by Emera Inc., calls it a great day for Nova Scotia.
"When it goes into operation in January, the Maritime Link will benefit Nova Scotia Power customers by creating a more stable and secure system, helping reduce carbon emissions, and enabling NSP to purchase power from new sources," Hutt said in a statement.
Alberta electricity price spike drives 25% CPI surge amid heatwave demand, coal-to-gas conversions, hydro shortfalls, and outages; consumers weigh fixed-rate plans, solar panels, home retrofits, and variable rates to manage bills and grid volatility.
Key Points
A recent 25% monthly rise in Alberta power prices driven by heatwave demand, constraints, outages, and fuel shifts.
✅ Heatwave pushed summer peak demand near record
✅ Coal-to-gas conversions and outages tightened supply
✅ Fixed-rate plans, solar, retrofits can reduce bill risk
Albertans might notice they are paying more when the next electricity bill comes in as bills on the rise in Calgary alongside provincial trends.
According to the consumer price index, Alberta saw its largest monthly increase since July 2015 as the price of electricity in Alberta rose 25 per cent amid rising electricity prices across the province.
“So I paid negative $70 last month. I actually made money. To supply power to the grid,” said Conrad Nobert, with Climate Action Edmonton.
Norbert is an environmental activist who favours solar power and is warning that prices will continue to go up along with the rising effects from climate change.
“My thoughts are that we can mitigate the price of power going up by taking climate action.”
Alberta experienced one of the hottest summers on record and many people were left scrambling to buy air conditioners.
That demand, along with a number of other factors, drove up prices, prompting some households to lock in rates for protection, says an assistant professor at the University of Calgary who teaches electricity systems.
“At the end of June, during the heatwave, we were a couple megawatts shy of setting an all-time record demand for electricity in the province. That would have been the first time that record for demand in the summer. Traditionally Alberta is a winter peaking province, as shown by an electricity usage record during a deep freeze not long ago,” explained Sara Hastings Simon, an assistant professor at the University of Calgary.
There are a few ways consumers can save money on their power bill; installing solar panels and retrofitting your home to opting for a fixed-rate plan, or considering protections like a consumer price cap where applicable.
“So by default, people are put into a variable rate plan, that changes month to month and that helps to manage prices so you don’t get that big surprise at where prices might be. I think we will get a lot more people looking at that option.”
A statement provided by Dale Nally, Alberta’s Associate Minister of natural gas and electricity, noted recent policy changes including the carbon tax repeal and price cap now in place that affect consumers, says in part:
“This period of high market prices is driven by low supplies of hydro-generated electricity from British Columbia and the pacific northwest, scheduled outages for coal-gas-conversions, unplanned infrastructure outages and unprecedented, and record-breaking high demand due to hot weather. We expect some of the factors that have caused recent increases in prices will be short-term.”
Los Angeles Power Station Fire prompts LADWP to shut a Northridge/Reseda substation, causing a San Fernando Valley outage amid a heatwave; high-voltage equipment and mineral oil burned as 94,000 customers lost power, elevator rescues reported.
Key Points
An LADWP substation fire in Northridge/Reseda caused a major outage; 94,000 customers affected as crews restore power.
✅ Fire started around 6:52 p.m.; fully extinguished by 9 p.m.
✅ High-voltage gear and mineral oil burned; no injuries reported.
✅ Outages hit Porter Ranch, Reseda, West Hills, Granada Hills.
About 94,000 customers were without electricity Saturday night after the Los Angeles Department of Water and Power shut down a power station in the northeast San Fernando Valley that caught fire, the agency said.
The fire at the station in the Northridge/Reseda area of Los Angeles started about 6:52 p.m. and involved equipment that carries high-voltage electricity and distributes it at lower voltages to customers in the surrounding area, the department said, even as other utilities sometimes deploy wildfire safety shut-offs to reduce risk during dangerous conditions.
The department shut off power to the station as a precautionary move, and it is restoring power now that the fire has been put out, similar to restoration after intentional shut-offs in other parts of California. Initially, 140,000 customers were without power. That number had been cut to 94,000 by 11 p.m.
The power outage comes as much of California baked in heat that broke records, and rolling blackout warnings were issued as the grid strained. A record that stood 131 years in Los Angeles was snapped when the temperature spiked at 98 degrees downtown.
People reported losing power in Porter Ranch, Winnetka, West Hills, Canoga Park, Woodland Hills, Granada Hills, North Hills, Reseda and Chatsworth, KABC TV reported, highlighting electricity inequality across communities.
Shortly after the blaze broke out, firefighters found a huge container of mineral oil that is used to cool electrical equipment on fire, Los Angeles Fire Department spokesman Brian Humphrey told the Los Angeles Times. The incident underscores infrastructure risks that in some regions have required a complete grid rebuild after severe storms.
Firefighters had the blaze under control by 8:30 p.m. and were able to put it out by 9 p.m., Humphrey said. "These were fierce flames, with smoke towering more than 300 feet into the sky," he told the newspaper.
No one was injured.
Firefighters rescued people who were stranded in elevators, Humphrey said.
Maine Hydropower Transmission Line revived by high court after referendum challenge, advancing NECEC, Hydro-Quebec supply, Central Maine Power partnership, clean energy integration, grid reliability, and lower rates across New England pending land-lease ruling.
Key Points
A court-revived NECEC line delivering 1,200 MW of Hydro-Quebec hydropower via CMP to strengthen the New England grid.
✅ Maine high court deems retroactive referendum unconstitutional
✅ Pending state land lease case may affect final route
✅ Project could lower rates and cut emissions in New England
Maine's highest court on Tuesday breathed new life into a $1-billion US transmission line that aims to serve as conduit for Canadian hydropower, after construction starts drew scrutiny, ruling that a statewide vote rebuking the project was unconstitutional.
The Supreme Judicial Court ruled that the retroactive nature of the referendum last year violated the project developer's constitutional rights, sending it back to a lower court for further proceedings.
The court did not rule in a separate case that focuses on a lease for a 1.6-kilometre portion of the proposed power line that crosses state land.
Central Maine Power's parent company and Hydro-Québec teamed up on the project that would supply up to 1,200 megawatts of Canadian hydropower, amid the ongoing Maine-Quebec corridor debate in the region. That's enough electricity for one million homes.
Most of the proposed 233-kilometre power transmission line would be built along existing corridors, but a new 85-kilometre section was needed to reach the Canadian border, echoing debates around the Northern Pass clash in New Hampshire.
Workers were already clearing trees and setting poles when the governor asked for work to be suspended after the referendum in November 2021, mirroring New Hampshire's earlier rejection of a Quebec-Massachusetts proposal that rerouted regional plans. The Maine Department of Environmental Protection later suspended its permit, but that could be reversed depending on the outcome of legal proceedings.
The high court was asked to weigh in on two separate lawsuits. Developers sought to declare the referendum unconstitutional while another lawsuit focused on a lease allowing transmission lines to cross a short segment of state-owned land.
Supporters say bold projects such as this one, funded by ratepayers in Massachusetts, are necessary to battle climate change and introduce additional electricity into a region that's heavily reliant on natural gas, which can cause spikes in energy costs, as seen with Nova Scotia rate increases recently across the Atlantic region.
Critics say the project's environmental benefits are overstated — and that it would harm the woodlands in western Maine.
It was the second time the Supreme Judicial Court was asked to weigh in on a referendum aimed at killing the project. The first referendum proposal never made it onto the ballot after the court raised constitutional concerns.
Although the project is funded by Massachusetts ratepayers, the introduction of so much electricity to the grid would serve to stabilize or reduce electricity rates for all consumers, proponents contend, even as Manitoba Hydro rate hikes face opposition elsewhere.
The referendum on the project was the costliest in Maine history, topping $90 million US and underscoring deep divisions.
The high-stakes campaign put environmental and conservation groups at odds, and pitted utilities backing the project, amid the Hydro One-Avista backlash, against operators of fossil fuel-powered plants that stand to lose money.
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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