Two utilities are seeking approval to build transmission lines across southern Colorado to serve a growing population and carry more electricity from renewable energy.
Xcel Energy and Tri-State Generation and Transmission Association filed applications with the Colorado Public Utilities Commission. The transmission lines would stretch from the San Luis Valley in south-central Colorado to Pueblo.
Xcel Energy gets power from a SunEdison solar plant in the San Luis Valley.
The utilities must get approval from local governments for the transmission lines. The project is expected to cost about $180 million and be in service in 2013.
"We are combining our resources and assets to put forward a strong plan that addresses load growth and supports future renewable energy development," said Kent Larson, Xcel Energy's vice president for transmission and operating services.
Xcel Energy spokesman Tom Henley said the application is the first joint project proposed for renewable energy zones identified by the Legislature.
Minneapolis-based Xcel Energy is Colorado's largest provider of electricity. Westminster-based Tri-State supplies wholesale power to 18 electric cooperatives in Colorado, New Mexico, Wyoming and Nebraska.
EU Electricity Price Limits are proposed by the European Commission to curb contagion from gas prices, bolster energy security, stabilize the power market, and manage inflation via LNG imports, gas storage, and reduced demand.
Key Points
Temporary power-price caps to curb gas contagion, shield consumers, and bolster EU energy security.
✅ Limits decouple electricity from volatile gas benchmarks
✅ Short-term LNG imports and storage to enhance supply security
✅ Market design reforms and demand reduction to tame prices
The European Union should consider emergency measures in the coming weeks that could include price cap strategies on electricity prices, European Commission President Ursula von der Leyen told leaders at an EU summit in Versailles.
The reference to the possible measures was contained in a slide deck Ms. von der Leyen used to discuss efforts to curb the EU’s reliance on Russian energy imports, which last year accounted for about 40% of its natural-gas consumption. The slides were posted to Ms. von der Leyen’s Twitter account.
Russia’s invasion of Ukraine has highlighted the vulnerability of Europe’s energy supplies to severe supply disruptions and raised fears that imports could be cut off by Moscow or because of damage to pipelines that run across Ukraine. It has also driven energy prices up sharply, contributing to worries about inflation and economic growth.
Earlier this week, the European Commission, the EU’s executive arm, published the outline of a plan that it said could cut imports of Russian natural gas by two-thirds this year and end the need for those imports entirely before 2030, aligning with calls to ditch fossil fuels in Europe. In the short-term, the plan relies largely on storing natural gas ahead of next winter’s heating season, reducing consumption and boosting imports of liquefied natural gas from other producers.
The Commission acknowledged in its report that high energy prices are rippling through the economy, even as European gas prices have fallen back toward pre-war levels, raising manufacturing costs for energy-intensive businesses and putting pressure on low-income households. It said it would consult “as a matter of urgency” and propose options for dealing with high prices.
The slide deck used by Ms. von der Leyen on Thursday said the Commission plans by the end of March to present emergency options “to limit the contagion effect of gas prices in electricity prices, including temporary price limits, even though rolling back electricity prices can be complex under current market rules.” It also intends this month to set up a task force to prepare for next winter and a proposal for a gas storage policy.
By mid-May, the Commission will set out options to revamp the electricity market and issue a proposal for phasing out EU dependency on Russian fossil fuels by 2027, according to the slides.
French President Emmanuel Macron said Thursday that Europe needs to protect its citizens and companies from the increase in energy prices, adding that some countries, including France, have already taken some national measures.
“If this lasts, we will need to have a more long-lasting European mechanism,” he said. “We will give a mandate to the Commission so that by the end of the month we can get all the necessary legislation ready.”
The problem with price limits is that they reduce the incentive for people and businesses to consume less, said Daniel Gros, distinguished fellow at the Centre for European Policy Studies, a Brussels think tank. He said low-income families and perhaps some businesses will need help dealing with high prices, but that should come as a lump-sum payment that isn’t tied to how much energy they are consuming.
“The key will be to let the price signal work,” Mr. Gros said in a paper published this week, which argued that high energy prices could result in lower demand in Europe and Asia, reducing the need for Russian natural gas. “Energy must be expensive so that people save energy,” he said.
Ms. von der Leyen’s slides suggest the EU hopes to replace 60 billion cubic meters of Russian gas with alternative suppliers, including suppliers of liquefied natural gas, by the end of this year. Another 27 billion cubic meters could be replaced through a combination of hydrogen and EU production of biomethane, according to the slide deck.
Gaza Electricity Crisis drives severe power cuts in the Gaza Strip, as Hamas-PA tensions and Mahmoud Abbas's supply reductions under blockade spur fuel shortages, hospital strain, and soaring demand for batteries, LED lights, and generators.
Key Points
A prolonged Gaza power shortage from politics, blockade, and fuel cuts, disrupting daily life, hospitals, and water.
✅ Demand surges for batteries, LED lights, and generators
✅ PA cuts to Israel-supplied power deepen shortages
✅ Hospitals, water, and sanitation face critical strain
In Imad Shlayl’s electronics shop in Gaza City, the customers crowding his store are interested in only two products: LED lights and the batteries to power them.
In the already impoverished Gaza Strip, residents have learned to adapt to the fact that electricity is only available for between two and four hours a day.
But fresh anger was sparked when availability was cut further last month, at the request of the Palestinian president, Mahmoud Abbas, in an escalation of his conflict with Hamas, the Islamist group.
The shortages have defined how people live their lives, echoing Europe’s energy crisis in other regions: getting up in the middle of the night, if there is power, to run washing machines or turn on water pumps.
Only the wealthy few have frequent, long-lasting access to electricity, even as U.S. brownout risks highlight grid fragility, to power lights and fans and fridges, televisions and wifi routers, in Gaza’s stifling summer heat.
“We used to sell all sorts of things,” says Shlayl. “But it’s different these days. All we sell is batteries and chargers. Because the crisis is so deep we are selling 100 batteries a day when normally we would sell 20.”
Gaza requires 430 megawatts of power to meet daily demand, but receives only half that. Sixty megawatts are supplied by its solitary power station, now short on fuel, while the rest is provided through the Israel’s power sector and funded by Abbas’s West Bank-based Palestinian Authority (PA).
Abbas’s move to cut supplies to Gaza, which is already under a joint Israeli and Egyptian blockade – now in its 11th year – has quickly made him a hate figure among many Gazans, who question why he is punishing 2 million fellow Palestinians in what appears to be an attempt to force Hamas to relinquish control of the territory.
Though business is good for Shlayl, he is angry at the fresh shortages faced by Gazans which, as pandemic power shut-offs elsewhere have shown, affect all areas of life, from hospital emergency wards to clean water supplies.
“I’ve not done anything to be punished by anyone. It is the worst I can remember but we are expecting it to get worse and worse,” he said. “Not just electricity, but other things as well. We are in a very deep descent.”
As well as cutting electricity, the PA has cut salaries for its employees in Gaza by upwards of 30% , prompting thousands to protest on the streets of Gaza city.
Residents also blame Abbas for a backlog in processing the medical referral process for those needing to travel out of Gaza for treatment, although who is at fault in that issue is less clear cut.
The problems facing Gaza – where high levels of unemployment are endemic – is most obvious in the poorest areas.
In Gaza City’s al-Shati refugee camp, home to the head of Hamas’s political bureau, Ismail Haniyeh, whole housing blocks were dark, while in others only a handful of windows were weakly illuminated.
In the one-room kiosk selling pigeons and chickens that he manages, just off the camp’s main market, Ayman Nasser, 32, is sitting on the street with his friends in search of a sea breeze.
His face is illuminated by the light of his mobile phone. He has one battery-powered light burning in his shop.
“Part of the problem is that we don’t have any news. Who should we blame for this? Hamas, Israelis, Abbas?” he said.
A Palestinian girl reads by candle light due to power cut at the Jabalia Camp in Gaza City Facebook Twitter Pinterest A Palestinian girl reads by candlelight due to a power cut at the Jabalia camp in Gaza City. Photograph: Anadolu Agency/Getty Images His friend, Ashraf Kashqin, interrupts: “It is all connected to politics, but it is us who is getting played by the two sides.”
If there is a question that all the Palestinians in Gaza are asking, it is what the ageing and remote Abbas hopes to achieve, a dynamic also seen in Lebanon’s electricity disputes, not least whether he hopes the cuts will lead to an insurrection against Hamas following demonstrations linked to the power supply in January.
While a senior official in the Fatah-led government on the West Bank said last month that the aim behind the move by the PA – which has been paying $12m (£9m) a month for the electricity Israel supplies to Gaza – was to “dry up Hamas’s financial resources”, others are dubious about the timing, the motive and the real impact.
Among them are human rights groups, such as Amnesty International, who have warned it could turn Gaza’s long-running crisis into a major disaster already hitting hospitals and waste treatment plants.
“For 10 years the siege has unlawfully deprived Palestinians in Gaza of their most basic rights and necessities. Under the burden of the illegal blockade and three armed conflicts, the economy has sharply declined and humanitarian conditions have deteriorated severely. The latest power cuts risk turning an already dire situation into a full-blown humanitarian catastrophe,” said Magdalena Mughrabi, of the group.
Then there is the question of timing. “Abbas is probably the only one who knows why he is doing this to Gaza,” adds Mohameir Abu Sa’da, a political science professor at Al Azhar University and analyst.
“I honestly don’t buy what he has been saying for the last three months: that he will take exceptional measures against Hamas to put pressure on it to give up control of the Gaza Strip.
2040 Energy Outlook projects a shifting energy mix as renewables scale, EV adoption accelerates, and IEA forecasts plateauing oil demand alongside rising natural gas, highlighting policy, efficiency, and decarbonization trends that shape global consumption.
Key Points
A data-driven view of future energy mix, covering renewables, fossil fuels, EVs, oil demand, and policy impacts.
✅ Renewables reach 16-30% by 2040, higher with strong policy support.
✅ Fossil fuels remain dominant, with oil flat and natural gas rising.
Which is more plausible: flying taxis, wind turbine arrays stretching miles into the ocean, and a solar roof on every house--or a scorched-earth, flooded post-Apocalyptic world?
We have no way of peeking into the future, but we can certainly imagine it. There is plenty of information about where the world is headed and regardless of how reliable this information is—or isn’t—we never stop wondering. Will the energy world of 20 years from now be better or worse than the world we live in now?
The answer may very well lie in the observable trends.
A Growing Population
The global population is growing, and it will continue to grow in the next two decades. This will drive a steady growth in energy demand, at about 1 percent per year, according to the International Energy Agency.
This modest rate of growth is good news for all who are concerned about the future of the planet. Parts of the world are trying to reduce their energy consumption, and this should have a positive effect on the carbon footprint of humanity. The energy thirst of most parts of the world will continue growing, however, hence the overall growth.
The world’s population is currently growing at a rate of a little over 1 percent annually. This rate of growth has been slowing since its peak in the 1960s and forecasts suggest that it will continue to slow. Growth in energy demand, on the other hand, may at some point stop moving in tune with population growth trends as affluence in some parts of the world grows. The richer people get, the more energy they need. So, to the big question: where will this energy come from?
The Rise of Renewables
For all the headline space they have been claiming, it may come as a disappointing surprise to many that renewable energy, excluding hydropower, to date accounts for just 14 percent of the global primary energy mix.
Certainly, adoption of solar and wind energy has been growing in leaps and bounds, with their global share doubling in five years in many markets, but unless governments around the world commit a lot more money and effort to renewable energy, by 2040, solar and wind’s share in the energy mix will still only rise to about 16 to 17 percent. That’s according to the only comprehensive report on the future of energy that collates data from all the leading energy authorities in the world, by non-profit Resources for the Future.
The growth in renewables adoption, however, would be a lot more impressive if governments do make serious commitments. Under that scenario, the share of renewables will double to over 30 percent by 2040, echoing milestones like over 30% of global electricity reached recently: that’s the median rate of all authoritative forecasts. Amongst them, the adoption rates of renewables vary between 15 percent and 61 percent by 2040.
Even the most bullish of the forecasts on renewables is still far below the 100-percent renewable future many would like to fantasize about, although BNEF’s 50% by 2050 outlook points to what could be possible in the power sector.
But in 2040, most of the world’s energy will still come from fossil fuels.
EV Energy
Here, forecasters are more optimistic. Again, there is a wide variation between forecasts, but in each and every one of them the share of electric vehicles on the world’s roads in 2040 is a lot higher than the meagre 1 percent of the global car fleet EVs constitute today. Related: Gas Prices Languish As Storage Falls To Near-Record Lows
Government policy will be the key, as U.S. progress toward 30% wind and solar shows how policy steers the power mix that EVs ultimately depend on. Bans of internal combustion engines will go a long way toward boosting EV adoption, which is why some forecasters expect electric cars to come to account for more than 50 percent of cars on the road in 2040. Others, however, are more guarded in their forecasts, seeing their share of the global fleet at between 16 percent and a little over 40 percent.
Many pin their hopes for a less emission-intensive future on electric cars. Indeed, as the number of EVs rises, they displace ICE vehicles and, respectively, the emission-causing oil that fuels for ICE cars are made from. It should be a no brainer that the more EVs we drive, the less emissions we produce. Unfortunately, this is not necessarily the case: China is the world’s biggest EV market, and its solar PV expansion has been rapid, it has the most EVs—including passenger cars and buses—but it is also one of the biggest emitters.
Still, by 2040, if the more optimistic forecasts come true, the world will be consuming less oil than it is consuming now: anywhere from 1.2 million bpd to 20 million bpd less, the latter case envisaging an all-electric global fleet in 2040.
This Ain’t Your Daddy’s Oil
No, it ain’t. It’s your grandchildren’s oil, for good or for bad. The vision of an oil-free world where renewable power is both abundant and cheap enough to replace all the ways in which crude oil and natural gas are used will in 2040 still be just that--a vision, with practical U.S. grid constraints underscoring the challenges. Even the most optimistic energy scenarios for two decades from now see them as the dominant source of energy, with forecasts ranging between 60 percent and 79 percent. While these extremes are both below the over-80 percent share fossil fuels have in the world’s energy mix, they are well above 50 percent, and in the U.S. renewables are projected to reach about one-fourth of electricity soon, even as fossil fuels remain foundational.
Still, there is good news. Fuel efficiency alone will reduce oil demand significantly by 2040. In fact, according to the IEA, demand will plateau at a little over 100 million bpd by the mid-2030s. Combined with the influx of EVs many expect, the world of 20 years from now may indeed be consuming a lot less oil than the world of today. It will, however, likely consume a lot more natural gas. There is simply no way around fossil fuels, not yet. Unless a miracle of politics happens (complete with a ripple effect that will cost millions of people their jobs) in 2040 we will be as dependent on oil and gas as we are but we will hopefully breathe cleaner air.
UAE Nuclear Power Plant launches the Barakah facility, delivering clean electricity to the Middle East under IAEA safeguards amid Gulf tensions, proliferation risks, and debates over renewables, natural gas, grid resilience, and energy security.
Key Points
The UAE Nuclear Power Plant, Barakah, is a civilian facility expected to supply 25% of electricity under IAEA oversight.
✅ Barakah reactors target 25% of national electricity.
✅ Operates under IAEA oversight, no enrichment per US 123 deal.
✅ Raises regional security, proliferation, and environmental concerns.
The United Arab Emirates became the first Arab country to open a nuclear power plant on Saturday, following a crucial step in Abu Dhabi earlier in the project, raising concerns about the long-term consequences of introducing more nuclear programs to the Middle East.
Two other countries in the region — Israel and Iran — already have nuclear capabilities. Israel has an unacknowledged nuclear weapons arsenal and Iran has a controversial uranium enrichment program that it insists is solely for peaceful purposes.
The U.A.E., a tiny nation that has become a regional heavyweight and international business center, said it built the plant to decrease its reliance on the oil that has powered and enriched the country and its Gulf neighbors for decades. It said that once its four units were all running, the South Korean-designed plant would provide a quarter of the country’s electricity, with Unit 1 reaching 100% power as a milestone toward commercial operations.
Seeking to quiet fears that it was trying to build muscle to use against its regional rivals, it has insisted that it intends to use its nuclear program only for energy purposes.
But with Iran in a standoff with Western powers over its nuclear program, Israel in the neighborhood and tensions high among Gulf countries, some analysts view the new plant — and any that may follow — as a security and environmental headache. Other Arab countries, including Saudi Arabia and Iraq, are also starting or planning nuclear energy programs.
The Middle East is already riven with enmities that pit Saudi Arabia and the U.A.E. against Iran, Qatar and Iran’s regional proxies. One of those proxies, the Yemen-based Houthi rebel group, claimed an attack on the Barakah plant when it was under construction in 2017.
And Iran is widely believed to be behind a series of attacks on Saudi oil facilities and oil tankers passing through the Gulf over the last year.
“The UAE’s investment in these four nuclear reactors risks further destabilizing the volatile Gulf region, damaging the environment and raising the possibility of nuclear proliferation,” Paul Dorfman, a researcher at University College London’s Energy Institute, wrote in an op-ed in March.
Noting that the U.A.E. had other energy options, including “some of the best solar energy resources in the world,” he added that “the nature of Emirate interest in nuclear may lie hidden in plain sight — nuclear weapon proliferation.” But the U.A.E. has said it considered natural gas and renewable energy sources before dismissing them in favor of nuclear energy because they would not produce enough for its needs.
Offering evidence that its intentions are peaceful, it points to its collaborations with the International Atomic Energy Agency, which has reviewed the Barakah project, and the United States, with which it signed a nuclear energy cooperation agreement in 2009 that allows it to receive nuclear materials and technical assistance from the United States while barring it from uranium enrichment and other possible bomb-development activities.
That has not persuaded Qatar, which last year lodged a complaint with the international nuclear watchdog group over the Barakah plant, calling it “a serious threat to the stability of the region and its environment.”
The U.A.E.’s oil exports account for about a quarter of its total gross domestic product. Despite its gusher of oil, it has imported increasing amounts of natural gas in recent years in part to power its energy-intensive desalination plants.
“We proudly witness the start of Barakah nuclear power plant operations, in alignment with the highest international safety standards,” Mohammed bin Zayed, the U.A.E.’s de facto ruler, tweeted on Saturday.
The new nuclear facility, which is in the Gharbiya region on the coast, close to Qatar and Saudi Arabia, is the first of several prospective Middle East nuclear plants, even as Europe reduces nuclear capacity elsewhere. Egypt plans to build a power plant with four nuclear reactors.
Saudi Arabia is also building a civilian nuclear reactor while pursuing a nuclear cooperation deal with the United States, and globally, China's nuclear program remains on a steady development track, though the Trump administration has said it would sign such an agreement only if it includes safeguards against weapons development.
Texas PUC Spanish Power to Choose mandates bilingual parity in deregulated electricity markets, ensuring equal access to plans, transparent pricing, consumer protection, and provider listings for Spanish speakers, mirroring the English site offerings statewide.
Key Points
PUC mandate requiring identical Spanish and English plan listings for fair access in the deregulated power market.
✅ Orders parity across English and Spanish plan listings
✅ Increases transparency in a deregulated electricity market
✅ Deadline set for providers to post on both sites
The state’s Public Utility Commission has ordered that the Spanish-language version of the Power to Choose website provide the same options available on the English version of the site, a move that comes as shopping for electricity is getting cheaper statewide.
Texas is one of a handful of states with a deregulated electricity market, with ongoing market reforms under consideration to avoid blackouts. The idea is to give consumers the option to pick power plans that they think best fit their needs. Customers can find available plans on the state’s Power To Choose website, or its Spanish-language counterpart, Poder de Escoger. In theory, those two sites should have the exact same offerings, so no one is disadvantaged. But the Texas Public Utility Commission found that wasn’t the case.
Houston Chronicle business reporter Lynn Sixel has been covering this story. She says the Power to Choose website is important for consumers facing the difficult task of choosing an electric provider in a deregulated state, where electricity complaints have recently reached a three-year high for Texans.
“There are about 57 providers listed on the [English] Power to Choose website, and news about retailers like Griddy underscores how varied the offerings can be across providers. [Last week] there were only 23 plans on the Spanish Power to Choose site,” Sixel says. “If you speak Spanish and you’re looking for a low-cost plan, as of last week, it would have been difficult to find some of the really great offers.”
Mustafa Tameez, managing director of Outreach Strategists, a Houston firm that consults with companies and nonprofits on diversity, described this issue as a type of redlining.
“He’s referring to a practice that banks would use to circle areas on maps in which the bank decided they did not want to lend money or would charge higher rates,” Sixel says. “Typically it was poor minority neighborhoods. Those folks would not get the same great deals that their Anglo neighbors would get.”
DeAnn Walker, chairman of the Public Utility Commission, said she was not at all happy about the plans listings in a meeting Friday, against a backdrop where Texas utilities have recently backed out of a plan to create smart home electricity networks.
“She gave a deadline of 8 a.m. Monday morning for any providers who wanted to put their plans on the Power to Choose website, must put them on both the Spanish language and the English language versions,” Sixel says. “All the folks that I talked to really had no idea that there were different plans on both sites and I think that there was sort of an assumption.”
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.
