Siemens has received an order for a high-voltage direct-current HVDC power transmission link in Canada. In a consortium with the construction company Mortenson Construction, Siemens will be supplying both converter stations for the Bipole III HVDC project.
Customer is provincially-owned Manitoba Hydro. Siemens is supplying the complete HVDC core technology, based on the well-proven thyristor-technology, while Mortensen Construction will be responsible for the construction of the converter stations.
This HVDC link of approximately 1,400 kilometers will connect the Keewatinohk Converter Station, in northern Manitoba near Hudson Bay with the Riel Converter Station, close to the provincial capital Winnipeg in the south of the province, by a +/-500 kilovolt kV overhead line.
The order is valued at more than CAD 800 million for the consortium. Once it has been commissioned in the summer of 2018, the Bipole III HVDC link will have a transmission capacity of 2,300 megawatts MW.
After the commissioning - planned for 2018 - the approximately 1,400 kilometers long HVDC link Bipole III will connect the Keewatinohk Converter Station, in northern Manitoba, with the Riel Converter Station, close to the provincial capital Winnipeg, by a +/-500 kilovolt kV overhead line. The picture shows the converter station of a comparable project in Australia.
This new HVDC link will enhance Manitoba Hydro's existing HVDC system by increasing overall system reliability. This HVDC link will transport electricity generated by hydroelectric generating stations in the northern part of the province with low losses to southern load centers and Winnipeg.
"When it comes to energy-efficient and low-loss transmission of high ratings of electricity over considerable distances, we're the right partner. Siemens is a leading provider of HVDC technology and with our partner who has the necessary local expertise in the construction we can offer systems tailored to our customers' requirements", says Karl Uecker, head of the business segments for HVDC and FACTS solutions within the Siemens Division Energy Management.
The scope of the contract includes the design, engineering, manufacturing, supply and commissioning of all HVDC core components, such as converter valves with direct light-triggered power thyristors, converter transformers, smoothing reactors, protection and I&C equipment, and AC and DC filters.
A particular challenge posed by this project is the need to design the system with all its equipment for temperatures as low as -50 degrees Celsius. This new HVDC link will bolster the power supply grid in the province and ensure that the rising demand for energy is met by linking further environmentally-friendly hydro power plants to the power grid.
HVDC transmission is the technology of choice when conventional methods of energy transport using alternating current reach their technical and economic limits.
Compared to a similar three-phase line the transmission losses with an HVDC link are 30 to 40 percent less. The use of HVDC transmission always makes sense when electricity is produced at locations other than where it is needed and must therefore be transported over vast distances to urban and industrial centers.
Demand Flexibility Service rewards households and businesses for shifting peak-time electricity use, enhancing grid balancing, energy security, and net zero goals with ESO and Ofgem support, virtual power plants, and 2GW capacity this winter.
Key Points
A grid program paying homes and businesses to shift peak demand, boosting energy security and lowering winter costs.
✅ Pays £3,000/MWh for reduced peak-time usage
✅ Targets at least 2GW via virtual power plants
✅ Rolled out by suppliers with Ofgem and ESO
This month we published our analysis of the British electricity system this winter. Our message is clear: in the base case our analysis indicates that supply margins are expected to be adequate, however this winter will undoubtedly be challenging, with high winter energy costs adding pressure. Therefore, all of us in the electricity system operator (ESO) are working round the clock to manage the system, ensure the flow of energy and do our bit to keep costs down for consumers.
One of the tools we have developed is the demand flexibility service, designed to complement efforts to end the link between gas and electricity prices and reduce bills. From November, this new capability will reward homes and businesses for shifting their electricity consumption at peak times. And we are working with the government, businesses and energy providers to encourage as high a level of take-up as possible. We are confident this innovative approach can provide at least 2 gigawatts of power – about a million homes’ worth.
What began as an initiative to help achieve net zero and keep costs down is also proving to be an important tool in ensuring Britain’s energy security, alongside the Energy Security Bill progressing into law.
We are particularly keen to get businesses involved right across Britain. When the Guardian first reported on this service we had calls from businesses ranging from multinationals to an owner of a fish and chip shop asking how they could do their bit and get signed up.
We can now confirm our proposals for how much people and businesses can be paid for shifting their electricity use outside peak times. We anticipate paying a rate of £3,000 per megawatt hour, reflecting the dynamics of UK natural gas and electricity markets today. Businesses and homes can become virtual power plants and, crucially, get paid like one too. For a consumer that could mean a typical household could save approximately £100, and industrial and commercial businesses with larger energy usage could save multiples of this.
We are working with Ofgem to get this scheme launched in November and for it to be rolled out through energy suppliers. If you are interested in participating, or understanding what you could get paid, please contact your energy supplier.
Innovations such as these have never mattered more. Vladimir Putin’s unlawful aggression means we are facing unprecedented energy market volatility, across the continent where Europe’s worst energy nightmare is becoming reality, and pressures on energy supplies this winter.
As a result of Russia’s war in Ukraine, European gas is scarce and prices are high, prompting Europe to weigh emergency measures to limit electricity prices amid the crisis. Alongside this, France’s nuclear fleet has experienced a higher number of outages than expected. Energy shortages in Europe could have knock-on implications for energy supply in Britain.
We have put in place additional contingency arrangements for this winter. For example, the ability to call on generators to fire-up emergency coal units, even as the crisis is a wake-up call to ditch fossil fuels for many, giving Britain 2GW of additional capacity.
We need to be clear, it is possible that without these measures supply could be interrupted for some customers for limited periods of time. This could eventually force us to initiate a temporary rota of planned electricity outages, meaning that some customers could be without power for up to three hours at a time through a process called the electricity supply emergency code (ESEC).
Under the ESEC process we would advise the public the day before any disconnections. We are working with government and industry on planning for this so that the message can be spread across all communities as quickly and accurately as possible. This would include press conferences, social media campaigns, and working with influencers in different communities.
US Electricity Demand 2018-2050 projects slower growth as energy consumption, power generation, air conditioning, and electric heating shift with efficiency standards, commercial floor space, industrial load, and household growth across the forecast horizon.
Key Points
A forecast of US power use across homes, commercial space, industrial load, and efficiency trends from 2018 to 2050.
✅ 2018 generation hit record; residential sales up 6%.
✅ Efficiency curbs demand; growth lags population and floor space.
✅ Commercial sales up 2%; industrial demand fell 3% in 2018.
Last year's Houston cold winter and hot summer drove power use to record levels, especially among households that rely on electricity for air conditioning during extreme weather conditions.
Electricity generation increased 4 per cent nationwide in 2018 and produced 4,178 million megawatt hours, driven in part by record natural gas generation across the U.S., surpassing the previous peak of 4,157 megawatt hours set in 2007, the Energy Department reported.
U.S. households bought 6 percent more electricity in 2018 than they did the previous year, despite longer-term declines in national consumption, reflecting the fact 87 percent of households cool their homes with air conditioning and 35 percent use electricity for heating.
Electricity sales to the commercial sector increased 2 percent in 2018 compared to the previous year while the industrial sector bought 3 percent less last year.
Going forward, the Energy Department forecasts that electricity consumption will grow at a slower pace than in recent decades, aligning with falling sales projections as technology improves and energy efficiency standards moderate consumption.
The economy and population growth are primary drivers of demand and the government predicts the number of households will grow at 0.7 percent per year from now until 2050 but electricity demand will grow only by 0.4 percent annually.
Likewise, commercial floor space is expected to increase 1 percent per year from now until 2050 but electricity sales will increase only by half that amount.
Globally, surging electricity demand is putting power systems under strain, providing context for these domestic trends.
COVID-19 Electricity Demand Shift flattens New York's load curve, lowers peak demand, and reduces wholesale prices as NYISO operators balance the grid amid stay-at-home orders, rising residential usage, cheap natural gas, and constrained renewables.
Key Points
An industry-wide change in load patterns: flatter peaks, lower prices, and altered grid operations during lockdowns.
✅ NYISO operators sequestered to maintain reliable grid control
✅ Morning and evening peaks flatten; residential use rises mid-day
✅ Wholesale prices drop amid cheap natural gas and reduced demand
At his post 150 miles up the Hudson, Jon Sawyer watches as a stay-at-home New York City stirs itself with each new dawn in this era of covid-19.
He’s a manager in the system that dispatches electricity throughout New York state, keeping homes lit and hospitals functioning, work that is so essential that he, along with 36 colleagues, has been sequestered away from home and family for going on four weeks now, to avoid the disease, a step also considered for Ontario power staff during COVID-19 measures.
The hour between 7 a.m. and 8 a.m. once saw the city bounding to life. A sharp spike would erupt on the system’s computer screens. Not now. The disease is changing the rhythms of the city, and, as this U.S. grid explainer notes, you can see it in the flows of electricity.
Kids are not going to school, restaurants are not making breakfast for commuters, offices are not turning on the lights, and thousands if not millions of people are staying in bed later, putting off the morning cup of coffee and a warm shower.
Electricity demand in a city that has been shut down is running 18 percent lower at this weekday morning hour than on a typical spring morning, according to the New York Independent System Operator, Sawyer’s employer. As the sun rises in the sky, usage picks up, but it’s a slower, flatter curve.
Though the picture is starkest in New York, it’s happening across the country. Daytime electricity demand is falling, even accounting for the mild spring weather, and early-morning spikes are deflating, with similar patterns in Ontario electricity demand as people stay home. The wholesale price of electricity is falling, too, driven by both reduced demand and the historically low cost of natural gas.
Sign up for our Coronavirus Updates newsletter to track the outbreak. All stories linked in the newsletter are free to access.
As covid-19 hits, coal companies aim to cut the tax they pay to support black-lung miners
Falling demand will hit the companies that run the “merchant generators” hardest. These are the privately owned power plants that sell electricity to the utilities and account for about 57 percent of electricity generation nationwide.
Closed businesses have resulted in falling demand. Residential usage is up — about 15 percent among customers of Con Edison, which serves New York City and Westchester County — as workers and schoolchildren stay home, while in Canada Hydro One peak rates remain unchanged for self-isolating customers, but it’s spread out through the day. Home use does not compensate for locked-up restaurants, offices and factories. Or for the subway system, which on a pre-covid-19 day used as much electricity as Buffalo.
Hospitals are a different story: They consume twice as much energy per square foot as hotels, and lead schools and office buildings by an even greater margin. And their work couldn’t be more vital as they confront the novel coronavirus.
Knowing that, Sawyer said, puts the ordinary routines of his job, which rely on utility disaster planning, the things about it he usually takes for granted, into perspective.
“Keeping the lights on: It comes to the forefront a little more when you understand, ‘I’m going to be sequestered on site to do this job, it’s so critical,’” he said, speaking by phone from his office in East Greenbush, N.Y., where he has been living in a trailer, away from his family, since March 23.
As coronavirus hospitalizations in New York began to peak in April, emergency medicine physician Howard Greller recorded his reflections. (Whitney Leaming/The Washington Post) Sawyer, 53, is a former submariner in the U.S. Navy, so he has experience when it comes to being isolated from friends and family for long periods. Many of his colleagues in isolation, who all volunteered for the duty, also are military veterans, and they’re familiar with the drill. Life in East Greenbush has advantages over a submarine — you can go outside and throw a football or Frisbee or walk or run the trail on the company campus reserved for the operators, and every day you can use FaceTime or Skype to talk with your family.
His wife understood, he said, though “of course it’s a sacrifice.” But she grasped the obligation he felt to be there with his colleagues and keep the power on.
“It’s a new world, it’s definitely an adjustment,” said Rich Dewey, the system’s CEO, noting that America’s electricity is safe for now. “But we’re not letting a little virus slow us down.”
There are 31 operators, two managers and four cooks and cleaners all divided between East Greenbush, which handles daytime traffic, and another installation just west of Albany in Guilderland, which works at night. The operators work 12-hour shifts every other day.
Computers recalibrate generation, statewide, to equal demand, digesting tens of thousands of data points, every six seconds. Other computers forecast the needs looking ahead 2½ hours. The operators monitor the computers and handle the “contingencies” that inevitably arise.
They dispatch the electricity along transmission lines ranging from 115,000 volts to 765,000 volts, much of it going from plants and dams in western and northern New York downstate toward the city and Long Island.
They always focus on: “What is the next worse thing that can happen, and how can we respond to that?” Sawyer said.
It’s the same shift and the same work they’ve always done, and that gives this moment an oddly normal feeling, he said. “There’s a routine to it that some of the people working at home now don’t have.”
Medical workers check in with them daily to monitor their physical health and mental condition. So far, there have been no dropouts.
Cheap oil doesn’t mean much when no one’s going anywhere
Statewide, the daily demand for electricity has fallen nearly 9 percent.
The distribution system in New England is looking at a 3 to 5 percent decline; the Mid-Atlantic states at 5 to 7 percent; Washington state at 10 percent; and California by nearly as much. In Texas, demand is down 2 percent, “but even there you’re still seeing drops in the early-morning hours,” said Travis Whalen, a utility analyst with S&P Global Platts.
In the huge operating system that embraces much of the middle of the country, usage has fallen more than 8 percent — and the slow morning surge doesn’t peak until noon.
In New York, there used to be a smaller evening spike, too (though starting from a higher load level than the one in the morning). But that’s almost impossible to see anymore because everyone isn’t coming home and turning on the lights and TV and maybe throwing a load in the laundry all at once. No one goes out, either, and the lights aren’t so bright on Broadway.
California, in contrast, had a bigger spike in the evening than in the morning before covid-19 hit; maybe some of that had to do with the large number of early risers spreading out the morning demand and highlighting electricity inequality that shapes access. Both spikes have flattened but are still detectable, and the evening rise is still the larger.
Only at midnight, in New York and elsewhere, does the load resemble what it used to look like.
The wholesale price of electricity has fallen about 40 percent in the past month, according to a study by S&P Global Platts. In California it’s down about 30 percent. In a section covered by the Southwest Power Pool, the price is down 40 percent from a year ago, and in Indiana, electricity sold to utilities is cheaper than it has been in six years.
Some of the merchant generators “are going to be facing some rather large losses,” said Manan Ahuja, also an analyst with S&P Global Platts. With gas so cheap, coal has built up until stockpiles average a 90-day supply, which is unusually large. Ahuja said he believes renewable generators of electricity will be especially vulnerable because as demand slackens it’s easier for operators to fine-tune the output from traditional power plants.
Bravado, dread and denial as oil-price collapse hits the American fracking heartland
As Dewey put it, speaking of solar and wind generators, “You can dispatch them down but you can’t dispatch them up. You can’t make the wind blow or the sun shine.”
Jason Tundermann, a vice president at Level 10 Energy, which promotes renewables, argued that before the morning and evening spikes flattened they were particularly profitable for fossil fuel plants. He suggested electricity demand will certainly pick up again. But an issue for renewable projects under development is that supply chain disruptions could cause them to miss tax credit deadlines.
With demand “on pause,” as Sawyer put it, and consumption more evenly spread through the day, the control room operators in East Greenbush have a somewhat different set of challenges. The main one, he said, is to be sure not to let those high-voltage transmission lines overload. Nuclear power shows up as a steady constant on the real-time dashboard; hydropower is much more up and down, depending on the capacity of transmission lines from the far northern and western parts of the state.
Some human habits are more reliably fixed. The wastewater that moves through New York City’s sewers — at a considerably slower pace than the electricity in the nearby wires — hasn’t shown any change in rhythm since the coronavirus struck, according to Edward Timbers, a spokesman for the city’s Department of Environmental Protection. People may be sleeping a little later, but the “big flush” still arrives at the wastewater treatment plants, about three hours or so downstream from the typical home or apartment, every day in the late morning, just as it always has.
Churchill Falls NL-Quebec Agreement boosts hydropower revenues, revises power purchase pricing, expands transmission lines, and integrates Indigenous rights, enabling renewable energy growth, domestic supply, exports, and interprovincial collaboration on infrastructure and utility modernization.
Key Points
A renegotiated hydropower deal reallocating power and advancing projects with Indigenous benefits in NL and Quebec.
✅ Raises Hydro-Quebec price for Churchill Falls electricity
✅ Increases NL power share for domestic use and exports
✅ Commits joint projects and Indigenous participation safeguards
St. John's, Newfoundland and Labrador - In a historic development, Newfoundland and Labrador (NL) and Quebec have reached a tentative agreement over the controversial Churchill Falls hydroelectric project, amid Quebec's electricity ambitions and longstanding regional sensitivities, potentially unlocking hundreds of billions of dollars for the Atlantic province. The deal, announced jointly by Premier Andrew Furey and Quebec Premier François Legault, aims to rectify the decades-long imbalance in the original 1969 contract, which saw NL receive significantly less revenue than Quebec for the province's vast hydropower resources.
The core of the new agreement involves a substantial increase in the price that Hydro-Québec pays for electricity generated at Churchill Falls. This price hike, retroactive to January 1, 2025, is expected to generate billions in additional revenue for NL over the next several decades. The deal also includes provisions for:
Increased power allocation for NL: The province will gain a larger share of the electricity generated at Churchill Falls, allowing for increased domestic consumption and potential export opportunities through the sale and trade of power across regional markets.
Joint infrastructure development: Both provinces will collaborate on new energy projects, in line with Hydro-Québec's $185-billion plan to reduce fossil fuel reliance, including potential expansions to the Churchill Falls generating station and the development of new transmission lines.
Indigenous involvement: The agreement acknowledges the importance of Indigenous rights and seeks to ensure that Indigenous communities in both provinces benefit from the project.
This landmark deal represents a significant victory for NL, which has long argued that the original 1969 contract was grossly unfair. The province has been seeking to renegotiate the terms of the agreement for decades, citing the low price paid for electricity and the significant economic benefits that have accrued to Quebec.
Key Implications:
Economic Transformation: The influx of revenue from the new Churchill Falls agreement has the potential to significantly transform the economy of NL, though the legacy of Muskrat Falls costs tempers expectations before plans are finalized. The province can invest in critical infrastructure projects, such as healthcare, education, and transportation, as well as support economic diversification initiatives.
Energy Independence: The increased access to electricity will enhance NL's energy security and reduce its reliance on fossil fuels. This shift towards renewable energy aligns with the province's climate change goals, and in the context of Quebec's no-nuclear stance could attract new investment in sustainable industries.
Interprovincial Relations: The successful negotiation of this complex agreement demonstrates the potential for constructive collaboration between provinces on major infrastructure projects, as seen in recent NB Power-Hydro-Québec agreements to import more electricity. It sets a precedent for future interprovincial partnerships on issues of shared interest.
Challenges and Considerations:
Implementation: The successful implementation of the agreement will require careful planning and coordination between the two provinces.
Environmental Impact: The expansion of hydroelectric generation at Churchill Falls must be carefully assessed for its potential environmental impacts, including the effects on local ecosystems and Indigenous communities.
Public Consultation: It is crucial that the governments of NL and Quebec engage in meaningful public consultation throughout the implementation process to ensure that the benefits of the agreement are shared equitably across both provinces.
The Churchill Falls agreement marks a turning point in the history of energy development in Canada. It demonstrates the potential for provinces to work together to achieve mutually beneficial outcomes, even as Nova Scotia shifts toward wind and solar after stepping back from the Atlantic Loop, while also addressing historical inequities and ensuring a more equitable distribution of the benefits of natural resources.
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.
California Income-Based Electricity Rates propose a fixed monthly fee set by income as utilities and the CPUC weigh progressive pricing, aiming to cut low-income bills while PG&E, SCE, and SDG&E retain usage-based charges.
Key Points
CPUC plan adds income-tiered fixed fees to lower low-income bills while keeping per-kWh usage charges.
✅ Adds fixed monthly fees by income to complement per-kWh charges
✅ Cuts bills for low-income households; higher earners pay more
✅ Utilities say revenue neutral; conservation signals preserved
California’s electric bills — already some of the highest in the nation — are rising as electricity prices soar across the state, but regulators are debating a new plan to charge customers based on their income level.
Typically what you pay for electricity depends on how much you use. But the state’s three largest electric utilities — Southern California Edison Company, Pacific Gas and Electric Company and San Diego Gas & Electric Company — have proposed a plan to charge customers not just for how much energy they use, but also based on their household income, moving toward income-based flat-fee utility bills over time. Their proposal is one of several state regulators received designed to accommodate a new law to make energy less costly for California’s lowest-income customers.
Some state Republican lawmakers are warning the changes could produce unintended results, such as weakening incentives to conserve electricity or raising costs for customers using solar energy, and some have introduced a plan to overturn the charges in the Legislature.
But the utility companies say the measure would reduce electricity bills for the lowest income customers. Those residents would save about $300 per year, utilities estimate.
California households earning more than $180,000 a year would end up paying an average of $500 more a year on their electricity bills, according to the proposal from utility companies.
The California Public Utilities Commission’s deadline for deciding on the suggested changes is July 1, 2024, as regulators face calls for action from consumers and advocates. The proposals come at a time when many moderate and low-income families are being priced out of California by rising housing costs.
Who wants to change the fee structure? Lawmakers passed and Gov. Gavin Newsom signed a comprehensive energy bill last summer that mandates restructuring electricity pricing across the state.
The Legislature passed the measure in a “trailer-bill” process that limited deliberation. Included in the 21,000-word law are a few sentences requiring the public utilities commission to establish a “fixed monthly fee” based on each customer’s household income.
A similar idea was first proposed in 2021 by researchers at UC Berkeley and the nonprofit thinktank Next 10. Their main recommendation was to split utility costs into two buckets. Fixed charges, which everyone has to pay just to be connected to the energy grid, would be based on income levels. Variable charges would depend on how much electricity you use.
Utilities say that part of customers’ bills still will be based on usage, but the other portion will reduce costs for lower- and middle-income customers, who “pay a greater percentage of their income towards their electricity bill relative to higher income customers,” the utilities argued in a recent filing.
They said the current billing system is unjust, regressive and fails to recognize differences in energy usage among households,
“When we were putting together the reform proposal, front and center in our mind were customers who live paycheck to paycheck, who struggle to pay for essentials such as energy, housing and food,” Caroline Winn, CEO of San Diego Gas & Electric in a statement.
The utilities say in their proposal that the changes likely would not reduce or increase their revenues.
James Sallee, an associate professor at UC Berkeley, said the utilities’ prior system of billing customers mostly by measuring their electric use to pay for what are essentially fixed costs for power is inefficient and regressive.
The proposed changes “will shift the burden, on average, to a more progressive system that recovers more from higher income households and less from lower income households,” he said.
