Russia and the United States signed a pact allowing the world's two biggest atomic powers to boost their nuclear trade and work on new ways to prevent the proliferation of nuclear weapons.
The civilian deal will open up the booming U.S. nuclear market and Russia's vast uranium fields to firms from both countries by removing Cold War restrictions that prevented bilateral trade potentially worth billions of dollars.
U.S. ambassador to Russia, William Burns, signed the deal with the head of Russia's state nuclear corporation, Sergei Kiriyenko, on the last full day of Vladimir Putin's presidency.
"The United States and Russia were once nuclear rivals - we are today nuclear partners," said Burns.
At the 2006 Group of Eight summit in St Petersburg, President George W. Bush and Putin ordered ministers to reach a deal but it has faced opposition from some U.S. congressmen because of Russia's nuclear cooperation with Iran.
A 123 agreement, so-called because it falls under section 123 of the U.S. Atomic Energy Act, is required before countries can cooperate on nuclear materials.
It is critical to the Global Nuclear Energy Partnership, or GNEP, which the United States and Russia have discussed for more than a year as a way to expand peaceful nuclear energy development and mitigate proliferation risks.
"What this agreement allows us to do is to implement some very creative ideas that both Russia and the United States have put forward to deal with the growing challenge of proliferation of nuclear weapons," Burns said.
He said the deal would allow Washington and Moscow to move forward on proposals for international nuclear fuel centers, which would sell developing countries access to nuclear energy but remove the need for their own enrichment programs.
Russia and the United States control the largest arsenals of nuclear weapons in the world and both have ambitious plans to build hundreds of new reactors for power production.
Some U.S. politicians have said nuclear cooperation with Russia should be shunned because Moscow is helping Iran build an atomic power station, but the Bush administration is keen to have the pact approved this year.
State Department spokesman Sean McCormack said in Washington that now that the deal has been signed, it would be sent to Congress for lawmakers to review "in due course".
When asked about speculation that Bush may not submit the deal to Congress - possibly leaving it for the next president to do - McCormack said: "Usually we don't sign agreements we don't intend to send to Congress for ratification."
Once the agreement is sent to lawmakers, it would go into force if Congress did not pass a disapproval resolution within 90 legislative days. Russia's parliament, controlled by Putin's party, must also ratify the treaty.
Russia, one of the world's biggest sellers of enrichment services, has been trying to break into the nuclear markets of the United States and European Union.
"The signing of this agreement opens a gigantic field of opportunities for the economic cooperation in the large and growing businesses linked to the civilian use of nuclear energy," Kiriyenko said after the signing.
Tuesday's agreement simplifies life for companies in both countries and allows them to strike deals on trade in nuclear materials directly among themselves.
Putin has reformed Russia's nuclear sector to boost competition and open it up to atomic firms such as Japan's Toshiba Corp, which owns U.S.-based Westinghouse Electric.
Russia has crafted a nuclear behemoth called Atomenergoprom - which officials say is an atomic version of Russian gas giant Gazprom - to compete with the biggest nuclear companies on the world market.
Rooftop Solar Battery Backup helps Californians keep lights on during PG&E blackouts, combining home energy storage with grid-tied systems for wildfire prevention, outage resilience, and backup power when solar panels cannot supply nighttime demand.
Key Points
A home battery paired with rooftop solar, providing backup power and blackout resilience when the grid is down.
✅ Works when grid is down; panels alone stop for safety.
✅ Requires home battery storage; market adoption is growing.
✅ Supports wildfire mitigation and PG&E outage preparedness.
Californians have embraced rooftop solar panels more than anyone in the U.S., but amid California's solar boom many are learning the hard way the systems won’t keep the lights on during blackouts.
That’s because most panels are designed to supply power to the grid -- not directly to houses, though emerging peer-to-peer energy models may change how neighbors share power in coming years. During the heat of the day, solar systems can crank out more juice than a home can handle, a challenge also seen in excess solar risks in Australia today. Conversely, they don’t produce power at all at night. So systems are tied into the grid, and the vast majority aren’t working this week as PG&E Corp. cuts power to much of Northern California to prevent wildfires, even as wildfire smoke can dampen solar output during such events.
The only way for most solar panels to work during a blackout is pairing them with solar batteries that store excess energy. That market is just starting to take off. Sunrun Inc., the largest U.S. rooftop solar company, said some of its customers are making it through the blackouts with batteries, but it’s a tiny group -- countable in the hundreds.
“It’s the perfect combination for getting through these shutdowns,” Sunrun Chairman Ed Fenster said in an interview. He expects battery sales to boom in the wake of the outages, as the state has at times reached a near-100% renewables mark that heightens the need for storage.
And no, trying to run appliances off the power in a Tesla Inc. electric car won’t work, at least without special equipment, and widespread U.S. power-outage risks are a reminder to plan for home backup.
Germany Energy Price Hikes are driving electricity tariffs, gas prices, and heating costs higher as wholesale markets surge after the Ukraine invasion; households face inflationary pressure despite relief measures and a renewables levy cut.
Key Points
Germany Energy Price Hikes reflect surging power and gas tariffs from wholesale spikes, prompting relief measures.
✅ Electricity tariffs to rise 19.5% in Apr-Jun
✅ Gas tariffs up 42.3%; heating and fuel costs soar
✅ Renewables levy ends July; saves €6.6 billion yearly
Record prices for electricity and gas in Germany will continue to rise in the coming months, the dpa agency, citing estimates from the consumer portal Verivox.
According to him, electricity suppliers and local utilities, in whose area of responsibility there are 13 million households, made an announcement of tariff increases in April, May and June by 19.5%. Gas tariffs increased by an average of 42.3%.
According to Verivox, electricity prices in Germany have approximately doubled over the year - a pattern seen as European electricity prices rose more than double the EU average - if previously a household with a consumption of 4,000 kWh paid 1,171 euros a year, now the amount has risen to 1,737 euros. Gas prices have risen even more, though European gas prices later returned to pre-Ukraine war levels: last year, a household with a consumption of 20,000 kWh paid 1,184 euros in annual terms, and now it is 2,787 euros.
Energy costs for the average German household are 52 percent higher than a year ago, adding to EU inflation pressures, according to energy contract sales website Check24. In a press release, the company said the wholesale electricity price was at €122.93 per megawatt-hour in February 2022, compared to €49 this time last year, while in the United States US electricity prices climbed at the fastest pace in 41 years. In addition, electricity prices on the power exchange haven been rising rapidly since Russian troops invaded Ukraine, comparison portal Strom Report said. Costs for heating rose the most, triggered by the high gas price (105 euros per megawatt-hour on the wholesale market) and around 100 USD per barrel of oil – its highest price since 2014. Driving also became more expensive with costs for petrol up 25 percent and diesel 30 percent, Check24 said.
The German government has decided on relief measures for low-income households, including a 200 billion euro energy shield, in response to high consumer energy costs. In July, it will abolish the renewables levy on the power price, saving consumers around €6.6 billion annually. In a reform proposal released this week, the ministry for economy and climate also detailed how it will legally oblige power suppliers to reduce their power bills when the levy is abolished.
Russia-Ukraine Energy War disrupts infrastructure, oil, gas, and electricity, triggering supply shocks, price spikes, and inflation. Global markets face volatility, import risks, and cybersecurity threats, underscoring energy security, grid resilience, and diversified supply.
Key Points
It is Russia's strategic targeting of Ukraine's energy system to disrupt supplies, raise prices, and hit global markets.
✅ Attacks weaponize energy to strain Ukraine and allies
✅ Supply shocks risk oil, gas, and electricity price spikes
✅ Urgent need for cybersecurity, grid resilience, diversification
Russia's targeting of Ukraine's energy infrastructure has unleashed an "energy war" that could lead to widespread price increases, supply disruptions, and ripple effects throughout the global energy market, felt across the continent, with warnings of Europe's energy nightmare taking shape.
This highlights the unprecedented scale and severity of the attacks on Ukrainian energy infrastructure. These attacks have disrupted power supplies, prompting increased electricity imports to keep the lights on, hindered oil and gas production, and damaged refineries, impacting Ukraine and the broader global energy system.
Energy as a Weapon
Experts claim that Russia's deliberate attacks on Ukraine's energy infrastructure represent a strategic escalation, amid energy ceasefire violations alleged by both sides, demonstrating the Kremlin's willingness to weaponize energy as part of its war effort. By crippling Ukraine's energy system, Russia aims to destabilize the country, inflict suffering on civilians, and undermine Western support for Ukraine.
Impacts on Global Oil and Gas Markets
The ongoing attacks on Ukraine's energy infrastructure could significantly impact global oil and gas markets, leading to supply shortages and dramatic price increases, even as European gas prices briefly returned to pre-war levels earlier this year, underscoring extreme volatility. Ukraine's oil and gas production, while not massive in global terms, is still significant, and its disruption feeds into existing anxieties about global energy supplies already affected by the war.
Ripple Effects Beyond Ukraine
The impacts of the "energy war" won't be limited to Ukraine or its immediate neighbours. Price increases for oil, gas, and electricity are expected worldwide, further fueling inflation and exacerbating the global cost of living crisis. Additionally, supply disruptions could disproportionately affect developing nations and regions heavily dependent on energy imports, making targeted energy security support to Ukraine and other vulnerable importers vital.
Vulnerability of Energy Infrastructure
The attacks on Ukraine highlight the vulnerability of critical energy infrastructure worldwide, as the country prepares for winter under persistent threats. The potential for other state or non-state actors to use similar tactics raises concerns about security and long-term stability in the global energy sector.
Strengthening Resilience
Experts emphasize the urgent need for global cooperation in strengthening the resilience of energy infrastructure. Investments in cybersecurity, diverse energy sources, and decentralized grids are crucial for mitigating the risks of future attacks, with some arguing that stepping away from fossil fuels would improve US energy security over time. International cooperation will be key in identifying vulnerable areas and providing aid to nations whose infrastructure is under threat.
The Unpredictable Future of Energy
The "energy war" unleashed by Russia has injected a new level of uncertainty into the global energy market. In addition to short-term price fluctuations and supply issues, the conflict could accelerate the long-term transition towards renewable energy sources and reshape how nations approach energy security.
Maryland Renewable Energy Violations highlight RPS compliance gaps as facilities selling renewable energy certificates, including waste-to-energy, biomass, and paper mills, face emissions and permit issues, prompting PSC and Attorney General scrutiny of environmental standards.
Key Points
Alleged RPS noncompliance by REC-eligible plants, prompting PSC review and potential decertification under Maryland law.
✅ Complaint targets waste-to-energy, biomass plants, and paper mills
✅ Facilities risk loss of REC certification for environmental violations
✅ PSC may investigate nonreporting; AG reviewing evidence
Many facilities that supply Maryland with renewable energy have exceeded pollution limits or otherwise broken environmental rules, violating a state law, according to a complaint sent by environmental groups to state energy and law enforcement officials.
Maryland law says that any company that contributes to a state renewable energy goal — half the state’s energy portfolio must come from renewable sources by 2030 — must “substantially comply” with rules on air and water quality and waste management. The complaint says more than two dozen power generators, including paper mills and trash incinerators, have records of formal or informal enforcement actions by environmental authorities.
For years, environmental groups have criticized Maryland policy that counts power plants that produce planet-warming carbon dioxide and health-threatening pollution as “renewable” energy generation, and similar tensions have emerged in California’s reliance on fossil fuels despite ambitious targets, but lawmakers concerned about protecting industrial jobs have resisted reforms. The renewable label qualifies the companies for subsidies drawn from energy bills across the state.
In a complaint filed this week, the groups asked the attorney general and Public Service Commission to step in.
“We’re subsidizing companies to produce dirty energy, but we’re also using ratepayer money to support companies that in many instances are paying environmental fines or just flouting the law,” said Timothy Whitehouse, executive director of Public Employees for Environmental Responsibility. “There’s no one to hold them to account in Maryland.”
A spokeswoman for Attorney General Brian Frosh said his office would review the complaint, which was signed by Whitehouse and Mike Ewall, executive director of the Energy Justice Network.
Public Service Commission officials said the facilities must notify them if found out of compliance with environmental rules, while at the federal level FERC action on aggregated DERs is shaping market participation, and the commission can then revoke certification under the state renewable energy program. In a statement, commission officials said they would launch an investigation if any facility had failed to notify them of any environmental violations, and encouraged anyone with evidence of such a transgression to file a complaint.
Companies named in the document accused the groups of painting an inaccurate picture.
“This complaint is based on misleading arguments designed to halt waste-to-energy practices that have clear environmental benefits recognized by the global scientific community,” said Jim Connolly, vice president of environment, health and safety for Wheelabrator, which owns a Baltimore trash incinerator.
Maryland launched its renewable energy program in 2004, diversifying the state’s energy portfolio with more environmentally friendly sources of power, even as regional debates over a Maine-Québec transmission line highlight cross-border impacts. Under the program, separate from the electricity they generate and sell to the grid, renewable power facilities can sell what are known as renewable energy certificates. Utilities such as Baltimore Gas and Electric Co. are required to buy a growing number of the certificates each year, essentially subsidizing the renewable energy facilities with money from ratepayer bills.
A dozen types of power generation qualify to sell the certificates: Solar, wind, geothermal and hydroelectric plants, as well as “biomass” facilities that burn wood and other organic matter, waste-to-energy plants that burn household trash and paper mills that burn a byproduct known as black liquor.
The complaint focuses on waste incinerators, biomass plants and paper mills, all of which environmental groups have cast as counter to the renewable energy program’s environmental goals, even as ACORE criticized a coal and nuclear subsidy proposal in federal proceedings.
“By subsidizing these corporations, Maryland is diverting the hard-earned income of Maryland ratepayers to wealthy corporations with poor environmental compliance records and undermining the state’s transition to clean renewable energy,” Whitehouse and Ewall wrote.
For example, they note that the Wheelabrator plant in Southwest Baltimore has been fined for exceeding mercury limits in the past. That occurred in 2011, when the plant settled with state regulators for violations in 2010 and 2009.
Connolly said there is “no question” the facility complies with Maryland’s renewable energy law.
Incinerators in Montgomery County and in Fairfax County, Virginia, that are owned by Covanta and sell the energy certificates in Maryland have been cited for accidental fires inside both facilities. The Maryland incinerator violated emissions rules in 2014, the same year that New Jersey forbade the Virginia facility from selling energy certificates into that state’s renewable energy program over concerns it wasn’t following ash testing regulations.
James Regan, a spokesman for Covanta, said both facilities “have excellent compliance records and they operate well below their permitted limits.” He said the Virginia facility is complying with ash testing requirements, and that both facilities emit far lower levels of pollutants such as particulate matter than vehicles do.
“It’s clear to us there’s a lot of misleading and wrong information in this document," Regan said.
The Environmental Protection Agency endorsed waste-to-energy facilities under former President Barack Obama because, while burning household trash emits carbon dioxide, scientists said that still had a smaller impact on global warming than sending trash to landfills, even as industry groups have backed the EPA in a legal challenge to the ACE rule as regulatory approaches shifted.
Environmentalists and community groups say the facilities still are harmful because they emit high levels of pollutants such as mercury, nitrogen oxides and lead. The concerns prompted Baltimore City Council to pass an ordinance in February that tightened emissions limits on the Wheelabrator facility, even as the new EPA pollution limits for coal and gas plants are being proposed, so dramatically that the company said it would no longer be able to operate once the rules go into effect in 2022.
The complaint does not mention the century-old Luke paper mill in Western Maryland that long faced criticism for its participation in the renewable energy program, but which owner Verso Co. closed this year.
It does say several of paper company WestRock’s mills in North Carolina and Virginia have faced both formal and informal EPA enforcement actions for violation of the Clean Water Act, including evolving EPA wastewater limits for power plants and other facilities, and the Clean Air Act. A WestRock spokesperson could not be reached for comment.
The complaint also says a large biomass facility in South Boston, Virginia, owned by the Northern Virginia Electric Cooperative has a record of noncompliance with the Clean Air Act over three years.
John Rainey, the plant’s operations director, said it “experienced some small exceedances to its permit limits,” but that it addressed the issues with Virginia environmental officials and has installed new technology.
All those plants have sold credits in Maryland.
Whitehouse said the environmental groups’ goal is to clean up Maryland’s renewable energy program. They did not file a lawsuit because he said there was no clear cause of action to take the state to court, but said he hopes the complaint nonetheless spurs action.
“It’s not acceptable in a clean energy program that we’re subsidizing some of the most dirty sources of energy,” he said. “Those sources aren’t even in compliance with the law, and no one seems to care.”
France Nuclear Power Outages threaten the grid as EDF reactors undergo stress corrosion inspections, maintenance delays, and staff shortages, driving electricity imports, peak-demand curtailment plans, and potential rolling blackouts during a cold snap across Europe.
Key Points
EDF maintenance and stress corrosion cut reactor output, forcing imports and blackouts as cold weather lifts demand.
✅ EDF inspects stress corrosion cracks in reactor piping
✅ Maintenance backlogs and skilled labor shortages slow repairs
✅ Government plans demand cuts, imports, and rolling blackouts
France is bracing for possible power outages in the coming days as falling temperatures push up demand while state-controlled nuclear group EDF struggles to bring more production on line.
WHY CAN'T FRANCE MEET DEMAND? France is one of the most nuclear-powered countries in the world, with a significant role of nuclear power in its energy mix, typically producing over 70% of its electricity with its fleet of 56 reactors and providing about 15% of Europe's total power through exports.
However, EDF (EDF.PA) has had to take a record number of its ageing reactors offline for maintenance this year just as Europe is struggling to cope with cuts in Russian natural gas supplies used for generating electricity, with electricity prices surging across the continent this year.
That has left France's nuclear output at a 30-year low, and mirrors how Europe is losing nuclear power more broadly, forcing France to import electricity and prepare plans for possible blackouts as a cold snap fuels demand for heating.
WHAT ARE EDF'S MAINTENANCE PROBLEMS? While EDF normally has a number of its reactors offline for maintenance, it has had far more than usual this year due to what is known as stress corrosion on pipes in some reactors, and during heatwaves river temperature limits have constrained output further.
At the request of France's nuclear safety watchdog, EDF is in the process of inspecting and making repairs across its fleet since detecting cracks in the welding connecting pipes in one reactor at the end of last year.
Years of under-investment in the nuclear sector mean that there is precious little spare capacity to meet demand while reactors are offline for maintenance, and environmental constraints such as limits on energy output during high river temperatures reduce flexibility.
France also lacks specialised welders and other workers in sufficient numbers to be able to make repairs fast enough to get reactors back online.
WHAT IS BEING DONE? In the very short term, after a summer when power markets hit records as plants buckled in heat, there is little that can be done to get more reactors online faster, leaving the government to plan for voluntary cuts at peak demand periods and limited forced blackouts.
In the very short term, there is little that can be done to get more reactors online faster, leaving the government to plan for voluntary cuts at peak demand periods and limited forced blackouts.
Meanwhile, EDF and others in the French nuclear industry are on a recruitment drive for the next generation of welders, pipe-fitters and boiler makers, going so far as to set up a new school to train them.
President Emmanuel Macron wants a new push in nuclear energy, even as a nuclear power dispute with Germany persists, and has committed to building six new reactors at a cost his government estimates at nearly 52 billion euros ($55 billion).
As a first step, the government is in the process of buying out EDF's minority shareholders and fully nationalising the debt-laden group, which it says is necessary to make the long-term investments in new reactors.
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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