Wave power delivers electricity to grid

By The Guardian, UK


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The first wave-power machine to supply the national grid has been operating successfully for a week in Orkney at Emec, the European Marine Energy Centre, raising hopes that wave farms will soon join off-shore wind farms as a feature of coastal Britain.

The Pelamis machine has a 750-kilowatt output, sufficient for up to 500 households, and is the first of a number of advanced prototypes being tried out in Orkney before being put into commercial production by Ocean Power Delivery of Edinburgh.

The plan is to have 40 machines together in a wave farm occupying a square kilometre (0.386 sq mile) of sea, supplying electricity sufficient for 20,000 households to the grid via a single cable under the seabed.

In principle, wave machines use the sea's vertical rise and fall to create changes in pressure, analogous to those on the pistons in the cylinders of a car engine, which are harnessed to drive a turbine; an underwater tide machine uses the alternate ebb and flow to drive a turbine directly. Along with off-shore wind, wave and tide power are potentially a vast electricity resource for the UK.

While wind is now accepted as a "mature technology" that is economically viable, the others are at the expensive development stage - though between them they could produce more energy than wind.

The Orkney centre will test various wave machine designs in all sorts of conditions before commercial production.

Undersea turbines are being tested in the West Country.

If all three technologies work, and could be harnessed together out at sea, it would greatly reduce costs because the same cabling could bring the electricity ashore.

Andrew Mill, Emec's managing director, said recently: "It was extremely satisfying to witness the closing of the circuit breaker seeing the meters register the first electric power flowing into the UK grid from an offshore wave powered renewable energy device."

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Power industry may ask staff to live on site as Coronavirus outbreak worsens

Power plant staff sequestration isolates essential operators on-site at plants and control centers, safeguarding critical infrastructure and grid reliability during the COVID-19 pandemic under DHS CISA guidance, with social distancing, offset shifts, and stockpiled supplies.

 

Key Points

A protocol isolating essential grid workers on-site to maintain operations at plants and control centers.

✅ Ensures grid reliability and continuity of critical infrastructure

✅ Implements social distancing, offset shifts, and isolation protocols

✅ Stockpiles food, beds, PPE, and sanitation for essential crews

 

The U.S. electric industry may ask essential staff to live on site at power plants and control centers to keep operations running if the coronavirus outbreak worsens, after a U.S. grid warning from the overseer, and has been stockpiling beds, blankets, and food for them, according to industry trade groups and electric cooperatives.

The contingency plans, if enacted, would mark an unprecedented step by power providers to keep their highly-skilled workers healthy as both private industry and governments scramble to minimize the impact of the global pandemic that has infected more than 227,000 people worldwide, with some utilities such as BC Hydro at Site C reporting COVID-19 updates as the situation evolves.

“The focus needs to be on things that keep the lights on and the gas flowing,” said Scott Aaronson, vice president of security and preparedness at the Edison Electric Institute (EEI), the nation’s biggest power industry association. He said that some “companies are already either sequestering a healthy group of their essential employees or are considering doing that and are identifying appropriate protocols to do that.”

Maria Korsnick, president of the Nuclear Energy Institute, said that some of the nation’s nearly 60 nuclear power plants are also “considering measures to isolate a core group to run the plant, stockpiling ready-to-eat meals and disposable tableware, laundry supplies and personal care items.”

Neither group identified specific companies, though nuclear worker concerns have been raised in some cases.

Electric power plants, oil and gas infrastructure and nuclear reactors are considered “critical infrastructure” by the federal government, and utilities continue to emphasize safety near downed lines even during emergencies. The U.S. Department of Homeland Security is charged with coordinating plans to keep them operational during an emergency.

A DHS spokesperson said that its Cybersecurity and Infrastructure Security Agency had issued guidance to local governments and businesses on Thursday asking them to implement policies to protect their critical staff from the virus, even as an EPA telework policy emerged during the pandemic.

“When continuous remote work is not possible, businesses should enlist strategies to reduce the likelihood of spreading the disease,” the guidance stated. “This includes, but is not necessarily limited to, separating staff by off-setting shift hours or days and/or social distancing.”

Public health officials have urged the public to practice social distancing as a preventative measure to slow the spread of the virus, and as more people work from home, rising residential electricity use is being observed alongside daily routines. If workers who are deemed essential still leave, go to work and return to their homes, it puts the people they live with at risk of exposure. 

California has imposed a statewide shutdown, asking all citizens who do not work in those critical infrastructure industries not to leave their homes, a shift that may raise household electricity bills for consumers. Similar actions have been put in place in cities across America.

 

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EU outlines $300 billion plan to dump Russian energy

REPowerEU Plan accelerates the EU's shift from Russian fossil fuels with renewable energy, energy efficiency, solar, wind, heat pumps, faster permits, and energy security measures by 2027, backed by grants, loans, and grid investments.

 

Key Points

EU plan to quit Russian fossil fuels via renewables and efficiency, with faster permits, by 2027.

✅ €300bn in grants and loans for efficiency and renewables

✅ Streamlined permits; solar mandate on new buildings

✅ Targets 2027 independence; cuts Russian gas, oil, coal

 

The European Union’s executive arm moved Wednesday to jump-start plans for the 27-nation bloc to abandon Russian energy amid the Kremlin’s war in Ukraine, proposing a nearly 300 billion-euro ($315 billion) package that includes more efficient use of fuels and faster rollout of renewable power, even as rolling back electricity prices remains challenging.

The European Commission’s investment initiative is meant to help the 27 EU countries start weaning themselves off Russian fossil fuels this year, a move many see as a wake-up call to ditch fossil fuels across Europe. The goal is to deprive Russia, the EU’s main supplier of oil, natural gas and coal, of tens of billions in revenue and strengthen EU climate policies.

“We are taking our ambition to yet another level to make sure that we become independent from Russian fossil fuels as quickly as possible,” European Commission President Ursula von der Leyen said in Brussels when announcing the package, dubbed REPowerEU.

With no end in sight to Russia’s war in Ukraine and European energy security shaken, amid what some describe as an energy nightmare for the region, the EU is rushing to align its geopolitical and climate interests for the coming decades. It comes amid troubling signs that have raised concerns about energy supplies that the EU relies on and have no quick replacements for, including Russia cutting off member nations Poland and Bulgaria after they refused a demand to pay for natural gas in rubles.

The bloc’s dash to ditch Russian energy stems from a combination of voluntary and mandatory actions. Both reflect the political discomfort of helping fund Russia’s military campaign in a country that neighbors the EU and wants to join the bloc.

An EU ban on coal from Russia is due to start in August, and the bloc has pledged to try to reduce demand for Russian gas by two-thirds by year's end, while debating gas price cap strategies to curb volatility. Meanwhile, a proposed EU oil embargo has hit a roadblock from Hungary and other landlocked countries that worry about the cost of switching to alternative sources.

In a bid to swing Hungary behind the oil phaseout, the REPowerEU package expects oil investment funding of around 2 billion euros for member nations highly dependent on Russian oil.

Energy savings and renewables form the cornerstones of the package, which would be funded mainly by an economic stimulus program put in place to help member countries overcome the slump triggered by the coronavirus pandemic.

The European Commission said the price tag for abandoning Russian fossil fuels completely by a 2027 target date is 210 billion euros. Its package includes 56 billion euros for energy efficiency and 86 billion euros for renewables.

Von der Leyen cited a total funding pot of 72 billion euros in grants and 225 billion euros for loans.

The European Commission also proposed ways to streamline the approval processes in EU countries for renewable projects, which can take up to a decade to get through red tape, as part of a broader effort to revamp the electricity market across Europe. The commission said approval times need to fall to as little as a year or less.

It put forward a specific plan on solar energy, seeking to double photovoltaic capacity by 2025 and pushing for a phased-in obligation to install solar panels on new buildings.

Simone Tagliapietra, an energy expert at the Bruegel think tank in Brussels, called REPowerEU a “jumbo package” whose success will ultimately depend on political will in the bloc’s national capitals, with examples such as Germany’s 200 billion euro energy price shield illustrating the scale of national responses.

“Most of the actions entailed in the plan require either national implementation or strong coordination among member states,” Tagliapietra said. “The extent to which countries really engage is going to be defining.”

The German energy think tank Agora Energiewende said the EU’s plan “gives too little attention to concrete initiatives that reduce fossil fuel demand in the short term and thereby misses the opportunity to simultaneously enhance Europe’s energy security and meet Europe’s climate objectives.”

The group's research shows rapidly expanding solar, wind parks and use of heat pumps for low-temperature heat in industry and buildings could be done faster than constructing new liquefied natural gas terminals or gas infrastructure, said Matthias Buck, its director for Europe.

The European Commission’s recommendations on short-term national actions to cut demand for Russian energy, which include potential emergency measures to limit electricity prices as well, coincide with deliberations underway in the bloc since last year on setting more ambitious EU energy-efficiency and renewable targets for 2030.

Those targets, being negotiated by the European Parliament and national governments, are part of the bloc’s commitments to a 55% cut in greenhouse gases by decade's end, compared with 1990 emissions, and to climate neutrality by 2050.

Von der Leyen urged the European Parliament and national governments to deepen the commission’s July proposal for an energy efficiency target of 9% and renewable energy goal of 40% by 2030. She said those objectives should be 13% and 45%, respectively.

Belgium, the Netherlands, Germany and Denmark plan to build North Sea wind farms to help cut carbon emissions.

 

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Biden administration pushes to revitalize coal communities with clean energy projects

Coal-to-Clean Energy Hubs leverage Bipartisan Infrastructure Law and Inflation Reduction Act funding to repurpose mine lands with microgrids, advanced nuclear, carbon capture, and rare earth processing, boosting energy security, jobs, and grid modernization.

 

Key Points

They are federal projects converting coal communities and mine lands into clean energy hubs, repurposing infrastructure.

✅ DOE demos on mine lands: microgrids, nuclear, carbon capture.

✅ Funding from BIL, CHIPS and IRA targets energy communities.

✅ Rare earths from coal waste bolster EV supply chains.

 

The Biden administration is channeling hundreds of millions of dollars in clean energy funding from recent legislation into its efforts to turn coal communities into clean energy hubs, the White House said.

The administration gave an update on its push across agencies to kick-start projects nationwide with funding Congress approved during Biden’s first two years in office. The effort includes $450 million from the Bipartisan Infrastructure Law that the Department of Energy will allocate to an array of new clean energy demonstration projects on former mine lands.

“These projects could focus on a range of technologies from microgrids to advanced nuclear to power plans with carbon capture,” Energy Secretary Jennifer Granholm said on a call with reporters Monday. “They’ll prove out the potential to reactivate or repurpose existing infrastructure like transmission lines and substations across an aging U.S. power grid, and these projects could spur new economic development in these communities.”

Among the projects the White House highlighted, it said $16 million from the infrastructure law will go to the University of North Dakota and West Virginia University to create design studies for the first-ever full-scale refinery facility in the U.S. that could extract and separate rare earth elements and minerals from coal mine waste streams. The materials are critical for electric vehicle-battery components that are currently heavily sourced from outside the U.S.

“Those efforts will pave the way toward building a first of its kind facility that produces essential materials for solar panels, wind turbines, EVs and more while cleaning up polluted land and water and creating good-paying jobs for local workers,” Granholm said.

Biden created an interagency working group focused on revitalizing coal-power communities through federal investments when he took office. In 2021, the group selected 25 priority areas ranging from West Virginia to Wyoming to focus on development, as high natural gas prices strengthened the case for clean electricity. There are nearly 18,000 identified mine sites across 1.5 million acres in the United States, according to the White House.

The massive effort fits into a broader Biden administration push to both fight climate change and support communities that have lost economic activity during a transition away from fossil fuel sources such as coal. While Biden’s most ambitious clean energy plans fell flat in Congress in the face of opposition from Republicans and some Democrats after the previous administration’s power plant overhaul, three major laws still unlocked funding for his administration to deploy.

Many of the initiatives are made possible through the Bipartisan Infrastructure Law, Chips and Science Act and the Inflation Reduction Act, even without a clean electricity standard on the books. The task force aims to make sure communities most affected by the changing energy landscape are taking maximum advantage of the federal benefits.

“Those new and expanded operations are coming to energy communities and creating good paying jobs,” Biden’s senior advisor for clean energy innovation and implementation John Podesta said on the call. “These laws can provide substantial federal support to energy communities like capping abandoned oil and gas wells, extracting critical minerals, building battery factories and launching demonstration projects in carbon capture or green hydrogen.”

The administration touted the potential benefits of the Inflation Reduction Act, a bill passed by Democrats to spur clean energy investments last year, even as early assessments show mixed results to date. At the time, U.S. consumers were dealing with decades-high inflation fueled in part by an energy crisis and high gas prices that drove debate — a point Republicans emphasized as the plan moved through Congress.

Deputy Treasury Secretary Wally Adeyemo said the Inflation Reduction Act aims to both “lower the deficit, as well as promote our energy security, lowering energy costs for consumers and combatting climate change.”

“As the Treasury works to implement the law, we’re focused on ensuring that all Americans benefit from the growth of the clean energy economy, particularly those who live in communities that have been dependent on the energy sector for job for a long time,” Adeyemo told reporters. “Economic growth and productivity are higher when all communities are able to reach their full potential.”

 

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Working From Home Will Drive Up Electricity Bills for Consumers

Remote Work Energy Costs are rising as home offices and telecommuting boost electricity bills; utilities, broadband usage, and COVID-19-driven stay-at-home policies affect productivity, consumption patterns, and household budgets across the U.K. and Europe.

 

Key Points

Remote Work Energy Costs are increased household electricity and utility expenses from telecommuting and home office use.

✅ WFH shifts energy load from offices to households.

✅ Higher device, lighting, and heating/cooling usage drives bills.

✅ Broadband access gaps limit remote work equity.

 

Household electricity bills are set to soar, with rising residential electricity use tied to the millions of people now working at home to avoid catching the coronavirus.

Running laptops and other home appliances will cost consumers an extra 52 million pounds ($60 million) each week in the U.K., according to a study from Uswitch, a website that helps consumers compare the energy prices that utilities charge.

For each home-bound household, the pain to the pocketbook may be about 195 pounds per year extra, even as some utilities pursue pandemic cost-cutting to manage financial pressures.

The rise in price for households comes even as overall demand is falling rapidly in Europe, with wide swaths of the economy shut down to keep workers from gathering in one place, and the U.S. grid overseer issuing warnings about potential pandemic impacts on operations.

People stuck at home will plug in computers, lights and appliances when they’d normally be at the office, increasing their consumption.

With the Canadian government declaring a state of emergency due to the coronavirus, companies are enabling work-from-home structures to keep business running and help employees follow social distancing guidelines, and some utilities have even considered housing critical staff on site to maintain operations. However, working remotely has been on the rise for a while.

“The coronavirus is going to be a tipping point. We plodded along at about 10% growth a year for the last 10 years, but I foresee that this is going to really accelerate the trend,” Kate Lister, president of Global Workplace Analytics.

Gallup’s State of the Workplace 2017 study found that 43% of employees work remotely with some frequency. Research indicates that in a five-day workweek, working remotely for two to three days is the most productive. That gives the employee two to three days of meetings, collaboration and interaction, with the opportunity to just focus on the work for the other half of the week.

Remote work seems like a logical precaution for many companies that employ people in the digital economy, even as some federal agencies sparked debate with an EPA telework policy during the pandemic. However, not all Americans have access to the internet at home, and many work in industries that require in-person work.

According to the Pew Research Center, roughly three-quarters of American adults have broadband internet service at home. However, the study found that racial minorities, older adults, rural residents and people with lower levels of education and income are less likely to have broadband service at home. In addition, 1 in 5 American adults access the internet only through their smartphone and do not have traditional broadband access. 

Full-time employees are four times more likely to have remote work options than part-time employees. A typical remote worker is college-educated, at least 45 years old and earns an annual salary of $58,000 while working for a company with more than 100 employees, according to Global Workplace Analytics, and in Canada there is growing interest in electricity-sector careers among younger workers. 

New York, California and other states have enacted strict policies for people to remain at home during the coronavirus pandemic, which could change the future of work, and Canadian provinces such as Saskatchewan have documented how the crisis has reshaped local economies across sectors.

“I don’t think we’ll go back to the same way we used to operate,” Jennifer Christie, chief HR officer at Twitter, told CNBC. “I really don’t.”

 

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Tesla updates Supercharger billing to add cost of electricity use for other than charging

Tesla Supercharger Billing Update details kWh-based pricing that now includes HVAC, battery thermal management, and other HV loads during charging sessions, improving cost transparency across pay-per-use markets and extreme climate scenarios.

 

Key Points

Tesla's update bills for kWh used by HVAC, battery heating, and HV loads during charging, reflecting true energy costs.

✅ kWh charges now include HVAC and battery thermal management

✅ Expect 10-25 kWh increases in extreme climates during sessions

✅ Some regions still bill per minute due to regulations

 

Tesla has updated its Supercharger billing policy to add the cost of electricity use for things other than charging, like HVAC, battery thermal management, etc, while charging at a Supercharger station, a shift that impacts overall EV charging costs for drivers. 

For a long time, Tesla’s Superchargers were free to use, or rather the use was included in the price of its vehicles. But the automaker has been moving to a pay-to-use model over the last two years in order to finance the growth of the charging network amid the Biden-era charging expansion in the United States.

Not charging owners for the electricity enabled Tesla to wait on developing a payment system for its Supercharger network.

It didn’t need one for the first five years of the network, and now the automaker has been fine-tuning its approach to charge owners for the electricity they consume as part of building better charging networks across markets.

At first, it meant fluctuating prices, and now Tesla is also adjusting how it calculates the total power consumption.

Last weekend, Tesla sent a memo to its staff to inform them that they are updating the calculation used to bill Supercharging sessions in order to take into account all the electricity used:

The calculation used to bill for Supercharging has been updated. Owners will also be billed for kWhs consumed by the car going toward the HVAC system, battery heater, and other HV loads during the session. Previously, owners were only billed for the energy used to charge the battery during the charging session.

Tesla says that the new method should more “accurately reflect the value delivered to the customer and the cost incurred by Tesla,” which mirrors recent moves in its solar and home battery pricing strategy as well.

The automaker says that customers in “extreme climates” could see a difference of 10 to 25 kWh for the energy consumed during a charging session:

Owners may see a noticeable increase in billed kWh if they are using energy-consuming features while charging, e.g., air conditioning, heating etc. This is more likely in extreme climates and could be a 10-25 kWh difference from what a customer experienced previously, as states like California explore grid-stability uses for EVs during peak events.

Of course, this is applicable where Tesla is able to charge by the kWh for charging sessions. In some markets, regulations push Tesla to charge by the minute amid ongoing fights over charging control between utilities and private operators.

Electrek’s Take
It actually looks like an oversight from Tesla in the first place. It’s fair to charge for the total electricity used during a session, and not just what was used to charge your battery pack, since Tesla is paying for both, even as some states add EV ownership fees like the Texas EV fee that further shape costs.

However, I wish Tesla would have a clearer way to break down the charging sessions and their costs.

There have been some complaints about Tesla wrongly billing owners for charging sessions, and this is bound to create more confusion if people see a difference between the kWhs gained during charging and what is shown on the bill.

 

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How the 787 uses electricity to maximise efficiency

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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