Ten years ago, on October 1, 1999, a milestone in the operations and reliability of the Eastern Interconnection took place – OATI successfully commissioned the NERC Interchange Distribution Calculator (NERC IDC) into operation.
NERC IDC was the first interconnection-wide secure information system providing critical functions to reliability operating entities in the Eastern Interconnection over the public Internet. Over the past 10 year period, NERC IDC has evolved into a highly automated information management system consisting of over twenty servers located in the OATI Data Center and Disaster Recovery sites.
NERC IDC includes an outage information exchange system (webSDX), interfaces with RTO markets for market dispatch flow contributions on flowgates, provides seams coordination information and computes Balancing AuthoritiesÂ’ native load flow contributions. NERC IDC calculates Transmission Distribution Factors (TDFs) for interchanges between 10,000 points and 2,000 flowgates three times per hour, and implements the NAESB TLR Business Practice Standard that manages interchange transactions, market dispatch and native load contributions.
“The extent of today’s IDC functionality, its 100% availability record for the last three years, and integration with Reliability Coordinators and Markets back end systems are proof of the great success of the NERC IDC,” stated Sasan Mokhtari, OATI President and CEO. “OATI appreciates the confidence that NERC and the Reliability Coordinators place on OATI in its ability to deliver uninterrupted secure critical services to reliability operating entities in the Eastern Interconnection.”
“The IDC model has proven very successful,” commented Michael Assante, Vice President and Chief Security Officer at NERC. “The tool continues to provide timely and important reliability information to the industry reliably and effectively.”
Jim Busbin, Chairman of the NERC IDC Working Group, congratulated OATI on ten very successful years of development and support of the NERC IDC, and stated “it has been my personal privilege to be a participant in this effort since it went into production and to enjoy the association through the years with the exceptionally professional staff of OATI. The IDC has evolved and expanded its functionality over its life and has continued to employ leading edge technology in the area of congestion management for the Eastern Interconnection. On behalf of NERC IDC Working Group members, past and present, we congratulate OATI on this important milestone and look forward to exploring the challenges that lie before us in the area of congestion management.”
Central Asia power shortages strain grids across Kazakhstan, Uzbekistan, Kyrgyzstan, Tajikistan, and Turkmenistan, driven by drought-hit hydropower, aging coal and gas plants, rising demand, cryptomining loads, and winter peak consumption risks.
Key Points
Regionwide blackouts from drought, aging plants and grids, rising demand, and winter peaks stressing Central Asia.
✅ Drought slashes hydropower in Kyrgyzstan, Tajikistan, Uzbekistan
✅ Aging coal and gas TPPs and weak grids cause frequent outages
✅ Cryptomining loads and winter heating spike demand and stress supply
Central Asians from western Kazakhstan to southern Tajikistan are suffering from power and energy shortages that have caused hardship and emergency situations affecting the lives of millions of people.
On October 14, several units at three power plants in northeastern Kazakhstan were shut down in an emergency that resulted in a loss of more than 1,000 megawatts (MW) of electricity.
It serves as an example of the kind of power failures that plague the region 30 years after the Central Asian countries gained independence and despite hundreds of millions of dollars being invested in energy infrastructure and power grids, and echo risks seen in other advanced markets such as Japan's near-blackouts during recent cold snaps.
Some of the reasons for these problems are clear, but with all the money these countries have allocated to their energy sectors and financial help they have received from international financial institutions, it is curious the situation is already so desperate with winter officially still weeks away.
The Current Problems Three power plants were affected in the October 14 shutdowns of units: Ekibastuz-1, Ekibastuz-2, and the Aksu power plant.
Ekibastuz-1 is the largest power plant in Kazakhstan, capable of generating some 4,000 MW, roughly 13 percent of Kazakhstan’s total power output.
The Kazakhstan Electricity Grid Operating Company (KEGOC) explained the problems resulted partially from malfunctions and repair work, but also from overuse of the system that the government would later say was due to cryptominers, a large number of whom have moved to Kazakhstan recently from China after Beijing banned the mining needed by Bitcoin and other cryptocurrencies, amid its own China's power cuts across several provinces in 2021.
But between November 8 and 9, rolling blackouts were reported in the East Kazakhstan, North Kazakhstan, and Kyzylorda provinces, as well as the area around Almaty, Kazakhstan’s biggest city, and Shymkent, its third largest city.
People in Uzbekistan say they, too, are facing blackouts that the Energy Ministry described as “short-term outages,” even as authorities have looked to export electricity to Afghanistan to support regional demand, though it has been clear for several weeks that the country will have problems with natural gas supplies this winter.
Power lines in Uzbekistan Kyrgyz President Sadyr Japarov continues to say there won't be any power rationing in Kyrgyzstan this winter, but at the end of September the National Energy Holding Company ordered “restrictions on the lighting of secondary streets, advertisements, and facades of shops, cafes, and other nonresidential customers.”
Many parts of Tajikistan are already experiencing intermittent supplies of electricity.
Even in Turkmenistan, a country with the fourth-largest reserves of natural gas in the world, there were reports of problems with electricity and heating in the capital, Ashgabat.
What Is Going On? The causes of some of these problems are easy to see.
The population of the region has grown significantly, with the population of Central Asia when the Soviet Union collapsed in late 1991 being some 50 million and today about 75 million.
Kyrgyzstan and Tajikistan are mountainous countries that have long been touted for their hydropower potential and some 90 percent of Kyrgyzstan’s domestically produced electricity and 98 percent of Tajikistan’s come from hydropower.
But a severe drought that struck Central Asia this year has resulted in less hydropower and, in general, less energy for the region, similar to constraints seen in Europe's reduced hydro and nuclear output this year.
Tajik authorities have not reported how low the water in the country’s key reservoirs is, but Kyrgyzstan has reported the water level in the reservoir at its Toktogul hydropower plant (HPP) is 11.8 billion cubic meters (bcm), the lowest level in years and far less than the 14.7 bcm of water it had in November 2020.
The Toktogul HPP, with an installed capacity of 1,200 MW, provides some 40 percent of the country's domestically produced electricity, but operating the HPP this winter to generate desperately needed energy brings the risk of leaving water levels at the reservoir critically low next spring and summer when the water is also needed for agricultural purposes.
This year’s drought is something Kyrgyzstan and Tajikistan will have to take into consideration as they plan how to provide power for their growing populations in the future. Hydropower is a desirable option but may be less reliable with the onset of climate change, prompting interest in alternatives such as Ukraine's wind power to diversify generation.
Uzbekistan is also feeling the effects of this year’s drought, and, like the South Caucasus where Georgia's electricity imports have increased, supply shortfalls are testing grids.
According to the International Energy Agency, HPPs account for some 12 percent of Uzbekistan’s generating capacity.
Uzbekistan’s Energy Ministry attributed low water levels at HPPs that have caused a 23 percent decrease in hydropower generation this year.
A reservoir in Kyrgyzstan Kazakhstan and Uzbekistan are the most populous Central Asian countries, and both depend on thermal power plants (TPP) for generating most of their electricity.
Most of the TPPs in Kazakhstan are coal-fired, while most of the TPPs in Uzbekistan are gas-fired.
Kazakhstan has 68 power plants, 80 percent of which are coal-fired TPPs, and most are in the northern part of the country where the largest deposits of coal are located. Kazakhstan has the world's 10th largest reserves of coal.
About 88 percent of Uzbekistan’s electricity comes from TTPs, most of which use natural gas.
Uzbekistan’s proven reserves are some 800 billion cubic meters, but gas production in Uzbekistan has been decreasing.
In December 2020, Uzbek President Shavkat Mirziyoev ordered a halt to the country’s gas exports and instructed that gas to be redirected for domestic use. Mirziyoev has already given similar instructions for this coming winter.
How Did It Come To This? The biggest problem with the energy infrastructure in Central Asia is that it is generally very old. Nearly all of its power plants date back to the Soviet era -- and some well back into the Soviet period.
The use of power plants and transmission lines that some describe as “obsolete” and a few call “decrepit” has unfortunately been a necessity in Central Asia, even as regional players pursue new interconnections like Iran's plan to transmit electricity to Europe as a power hub.
Reporting on Kazakhstan in September 2016, the Asian Development Bank (ADB) said, “70 percent of the power generation infrastructure is in need of rehabilitation.”
The Ekibastuz-1 TPP is relatively new by the power-plant standards of Central Asia. The first unit of the eight units of the TPP was commissioned in 1980.
The first unit at the AKSU TPP was commissioned in 1968, and the first unit of the gas- and fuel-fired TPP in southern Kazakhstan’s Zhambyl Province was commissioned in 1967.
California Utility Spending Bill scrutinizes how ratepayer funds are used by utilities, targeting lobbying, advertising, wildfire prevention cost pass-throughs, and CPUC oversight to curb high electricity bills and increase accountability and transparency statewide.
Key Points
Legislation restricting utilities from using ratepayer money for lobbying and ads, with stronger CPUC oversight.
✅ Bans ratepayer-funded lobbying and political advertising
✅ Expands prohibited utility communications and influence spending
✅ Aims to curb bills, boost transparency, and CPUC accountability
California's legislators are about to vote on a bill that would impose stricter regulations on how utility companies spend the money they collect from ratepayers. This legislation directly responds to the growing discontent among Californians who are already grappling with high electricity bills, as Californians ask why electricity prices are soaring amid wildfire prevention efforts.
Consumer rights groups have been vehemently critical of how utilities have been allocating customer funds, amid growing calls for regulatory action from state officials. They allege that a substantial portion of this money is being funnelled into lobbying efforts and advertising campaigns that yield no direct benefits for the customers themselves.
The proposed bill would significantly broaden the definition of what constitutes prohibited advertising and political influence activities on the part of utility companies, separate from income-based fixed electricity charges proposals that affect rate design. This would effectively restrict the ways in which utilities can utilize customer funds for such purposes.
While consumer advocacy groups have favored the legislation, it has drawn opposition from utility companies and some labor unions, as lawmakers weigh overturning income-based utility charges in parallel debates. Opponents contend that it would hinder utilities' ability to communicate effectively with their customers and advocate for their interests. Additionally, they express concerns that the bill could result in job losses within the utility sector.
The vote on the bill is expected to take place on Monday. The outcome of the vote is uncertain, but it is sure to be a closely watched development for Californians struggling with the burden of high electricity bills, with many wondering about major changes to their electric bills in the near term.
California's Electricity Rates: A Burden for Residents
A recent report by the California Public Utilities Commission (CPUC) revealed that the average Californian household spends a significantly higher amount on electricity compared to the national average. This disparity in electricity rates can be attributed to a number of factors, including the financial costs associated with wildfire prevention measures, investments in renewable energy infrastructure, and maintenance of aging electrical grids, even as the state considers revamping electricity rates to clean the grid.
Examples of Utility Company Spending that Raise Concerns
Consumer rights groups have specifically highlighted instances where utility companies have used customer money to fund lavish executive compensation packages, sponsor professional sports teams, and finance political campaigns. They argue that these expenditures do not provide any tangible benefits to ratepayers and should not be funded through customer bills.
The Need for Accountability and Prioritization
Proponents of the bill believe that the legislation is necessary to ensure that utility companies are held accountable for how they spend customer funds. They believe that the stricter regulations would compel utilities to prioritize investments that directly improve the quality and reliability of electricity services for Californians, alongside discussions of income-based flat-fee utility bills that could reshape rate structures.
The impending vote on the bill underscores the ongoing tension between the need for reliable electricity services and the desire to keep utility rates affordable for Californians. The outcome of the vote is likely to have a significant impact on how utility companies operate in the state and how much Californians pay for their electricity.
Hydro-Qu E9bec Class-Action Lawsuit alleges overbilling and monopoly abuse, citing R E9gie de l' E9nergie rate increases, Quebec Superior Court filings, and calls for refunds on 2008-2013 electricity bills to residential and business customers.
Key Points
Quebec class action alleging Hydro-Qu E9bec overbilled customers in 2008-2013, seeking court-ordered refunds.
✅ Filed in Quebec Superior Court; certification pending.
✅ Alleges up to $1.2B in overcharges from 2008-2013.
✅ Questions R E9gie de l' E9nergie rate approvals and data.
A group representing Hydro-Québec customers has filed a motion for a class-action lawsuit against the public utility, alleging it overcharged customers over a five-year period.
Freddy Molima, one of the representatives of the Coalition Peuple allumé, accuses Hydro-Québec of "abusing its monopoly."
The motion, which was filed in Quebec Superior Court, claims Hydro-Québec customers paid more than they should have for electricity between 2008 and 2013, to the tune of nearly $1.2 billion, even as Hydro-Québec later refunded $535 million to customers in a separate case.
The coalition has so far recruited nearly 40,000 participants online as part of its plan to sue the public utility.
A lawyer representing the group said Quebec's energy board, the Régie de l'énergie, also recently approved Hydro-Québec rate increases for residential and business customers without knowing all the facts, even as Manitoba Hydro hikes face opposition in regulatory hearings.
"There's certain information provided to the Régie that isn't true," said Bryan Furlong. "Hydro-Québec has not been providing the Régie the proper numbers."
In its motion, the group asks that overcharged clients be retroactively reimbursed.
Hydro-Québec denies allegations
Hydro-Québec, for its part, denies it ever overbilled any of its clients, while other utilities such as Hydro One plan to redesign bills to improve clarity.
"All our efficiencies have been returned to the government through our profits, and to Quebecers we have billed exactly what we agreed to bill," said spokesperson Serge Abergel, adding that the utility won't seek a rate hike next year according to its current plans.
Quebec Energy Minister Pierre Moreau also came to the public utility's defence, saying it has no choice but to comply with the energy board's regulations, while customer protections are in focus as Hydro One moves to reconnect 1,400 customers in Ontario.
The group says the public utility has overbilled clients by up to $1.2 billion. (Radio-Canada)
It would be "shocking" if customers were charged too much money, he added.
"I know for a fact that Hydro-Québec is respecting the decision of this body," he said.
While the motion has been filed, the group cannot say how much each customer would receive if the class-action lawsuit goes ahead because it all depends on how much electricity was consumed by each client over that five-year period.
The coalition plans to present its motion to a judge next February.
Canada Electricity Shortage threatens renewable energy transition as EV adoption and building decarbonization surge; Hydro-Quebec exports, wind power expansion, demand response, and smart grid resilience shape investment and capacity planning.
Key Points
A looming supply gap in central and eastern provinces driven by EVs, heating decarbonization, exports, and limited new hydro.
✅ Hydro-Quebec capacity pressured by exports and new loads
✅ Wind power prioritized; new mega-dams deemed unworkable
✅ Smart meters boost flexibility but raise cyber risk
Quebec and other provinces in central and eastern Canada are heading toward a significant shortage of electricity to respond to the various needs of a transition to renewable energy, and Ontario's energy storage push underscores how supply is tightening across the region.
This is according to Polytechnique Montréal’s Institut de l’énergie Trottier, which published a report titled A Strategic Perspective on Electricity in Central and Eastern Canada last week.
The white paper says that at the current rate, most provinces will be incapable of meeting the electricity needs created by the increase in the number of electric vehicles, including the federal 2035 EV sales mandate that will amplify demand, and the decarbonization of building heating by 2030. “The situation worsens if we consider carbon neutrality objectives of the federal government and some provinces for 2050,” the institute says.
The researchers called on public utilities to immediately review their investment plans for the coming years in light of examples such as B.C.'s power supply challenges that accompany rapid green ambitions.
In a news conference Wednesday, Premier François Legault said the province could indeed be short on electricity as debates over Quebec's EV push continue. “We’re open to exploiting green hydrogen, if the price is good and also based on the electrical capacity we have. Because currently, we predict that in the coming years we’re going to lack electricity, so we must be prudent.”
Quebec is in a better position than other provinces because it is the largest hydroelectricity producer in the country. But that energy source also attracts new clients that have contributed to increased demand over the coming years, including data centres, cryptocurrency miners and greenhouses.
Report co-author Normand Mousseau said that while Hydro-Québec largely has the capacity to meet demand from electric vehicles, even amid EV shortages and wait times for buyers, heating and manufacturers, export contracts to the United States “risk reducing its leeway.”
Hydro-Québec will therefore have to find new sources of electricity, and Mousseau said the answer isn’t new dams.
“The reservoirs give an immense flexibility to the network, but we don’t have the capacity today to flood territories like we have done in the past,” said Mousseau, the institute’s scientific director. “From an environmental viewpoint and a social accessibility one, it’s unworkable.”
The solution would be more wind turbines, he said, adding construction could happen at “very competitive rates” and if there’s a surplus, “we can sell it without issue because other provinces are in an even worse situation than ours,” a reality echoed by eco groups in Northern Ontario sustainability discussions focused on the grid’s future.
The researchers propose solutions based on six themes: regulations, pricing, demand management, data, support for implementation and resilience.
In the resilience category, the report notes that innovative technology like smart meters makes the network more flexible, with pilots such as EV-to-grid integration in Nova Scotia illustrating emerging options, but also increases the risk of cyberattacks. The more extreme weather caused by climate change also increases the risks of damage to infrastructure while at the same time increasing demand.
Northern Pass Hydropower Project Rehearing faces review by New Hampshire's Site Evaluation Committee as Eversource seeks approval for a 192-mile transmission line, citing energy cost relief, while Massachusetts eyes Central Maine Power as an alternative.
Key Points
A review of Eversource's halted NH transmission plan, weighing impacts, costs, and alternatives.
✅ SEC denied project, Eversource seeks rehearing
✅ 192-mile line to bring Canadian hydropower to NE
✅ Alternative bids include Central Maine Power corridor
Groups supporting and opposing the Northern Pass hydropower project in New Hampshire filed statements Friday in advance of a state committee’s meeting next week on whether it should rehear the project.
The Site Evaluation Committee rejected the transmission proposal last month over concerns about potential negative impacts. It is scheduled to deliberate Monday on Eversource’s request for a rehearing.
The $1.6 billion project would deliver hydropower from Canada, including Hydro-Quebec exports, to customers in southern New England through a 192-mile transmission line in New Hampshire.
If the Northern Pass project fails to ultimately win New Hampshire approval, the Massachusetts Department of Energy Resources has announced it will begin negotiating with a team led by Central Maine Power Co. for a $950 million project through a 145-mile Maine transmission line as an alternative.
Separately, construction later began on the disputed $1 billion electricity corridor despite ongoing legal and political challenges.
The Business and Industry Association voted last month to endorse the project after remaining neutral on it since it was first proposed in 2010. A letter sent to the committee Friday urges it to resume deliberations. The association said it is concerned about the severe impact the committee’s decision could have on New Hampshire’s economic future, even as Connecticut overhauls electricity market structure across New England.
“The BIA believes this decision was premature and puts New Hampshire’s economy at risk,” organization President Jim Roche wrote. “New Hampshire’s electrical energy prices are consistently 50-60 percent higher than the national average. This has forced employers to explore options outside New Hampshire and new England to obtain lower electricity prices. Businesses from outside New Hampshire and others now here are reversing plans to grow in New Hampshire due to the Site Evaluation Committee’s decision.”
The International Brotherhood of Electrical Workers and the Coos County Business and Employers Group also filed a statement in support of rehearing the project.
The Society to Protect New Hampshire Forests, which is opposed to the project, said Eversource’s request is premature because the committee hasn’t issued a final written decision yet. It also said Eversource hasn’t proven committee members “made an unlawful or unreasonable decision or mistakenly overlooked matters it should have considered.”
As part of its request for reconsideration, Eversource said it is offering up to $300 million in reductions to low-income and business customers in the state.
It also is offering to allocate $95 million from a previously announced $200 million community fund — $25 million to compensate for declining property values, $25 million for economic development and $25 million to promote tourism in affected areas. Another $20 million would fund energy efficiency programs.
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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