Tennessee environmental officials are asking for newer data before renewing a permit for millions of gallons of warm water discharged daily by the Tennessee Valley Authority's Watts Bar nuclear plant.
The five-year permit for releasing cooling water into the Tennessee River expired in November 2006, and the nation's largest public utility has been operating under a temporary extension since then, in part because of delays by regulators themselves.
State officials say TVA continues to meet requirements for the plant's withdrawals and discharges into the river.
Still, the Tennessee Department of Environment and Conservation wants TVA to update 15-year-old data used to support the new permit. They also found problems with a self-monitoring program at the plant. And they say they won't consider a second reactor now under construction at Watts Bar until later.
The single-reactor Watts Bar station, some 50 miles south of Knoxville, draws about 150,000 gallons a minute from the river. It returns slightly less because of evaporation in the cooling process. The discharge mixes with 3 million to 4 million gallons a minute already flowing by the plant.
Nuclear plants are subject to restrictions on the temperature of the discharged coolant because hot water can kill fish or plants or otherwise disrupt the environment.
Those restrictions, coupled with the drought, led to a one-day shutdown last August of a TVA reactor at Browns Ferry in Alabama, which also taps the Tennessee River.
This has never been a problem for Watts Bar. The plant is closer to TVA's deep reservoirs north of Knoxville that can send a wave of cold water downriver when temperatures rise. The discharge limit is 95 degrees. Watts Bar didn't get above 90 degrees last summer.
TDEC spokeswoman Tisha Calabrese-Benton said there have been "no temperature violations even in the drought" at the 12-year-old Watts Bar station, a 1,200-megawatt plant capable of powering 650,000 homes.
The old permit, which covers process wastewater, cooling water and stormwater runoff, will remain "fully effective and fully enforceable" until a new permit is issued, said Saya Qualls, TDEC's chief engineer.
"There have been no changes to the site since (the last permit) was issued. So there is nothing that is happening or can happen as the result of the permit being 'administratively continued'" or extended, she said.
However, DHEC wants TVA to update 1993 monitoring data in its new permit application.
"They have asked for new numbers and we are going to give them to them," TVA spokesman Gil Francis said.
The Nuclear Regulatory Commission raised a similar complaint in March to TVA's application to build and operate a next-generation nuclear plant at the Bellefonte site in Alabama. TVA used a decade-old computer model supported by 1963 data to forecast river flooding and was asked to provide new data for that, too.
Tennessee monitors long-term environmental trends in its rivers, but it relies on licensees to monitor themselves on a daily basis. The state follows up with annual inspections.
TDEC's 2007 annual inspection at Watts Bar discovered a self-monitoring problem — a broken flow meter that measures discharged water moving from one holding pond to another within the plant — and a leaking fire protection line. Both problems were fixed, though it took more than a year to replace the flow meter.
Watts Bar was the last new nuclear plant in this country when it came online with a single reactor in 1996. TVA is now spending $2.5 billion to complete the plant's second reactor by 2013.
Qualls said the pending discharge permit will run through 2011. She expects the second reactor won't be considered until the next permit comes under review, probably in 2010.
Blood Nickel spotlights ethical sourcing in the EV supply chain, linking nickel mining to human rights, environmental impact, ESG standards, and Canadian leadership in sustainable extraction, transparency, and community engagement across global battery materials markets.
Key Points
Blood Nickel is nickel mined under unethical or harmful conditions, raising ESG, human rights, and environmental risks.
✅ Links EV battery supply chains to social and environmental harm
✅ Calls for transparency, traceability, and ethical sourcing standards
✅ Highlights Canada's role in sustainable mining and community benefits
The rise of electric vehicles (EVs) has sparked a surge in demand for essential battery components, particularly nickel, and related cobalt market pressures essential for their batteries. This demand has ignited concerns about the environmental and social impacts of nickel mining, particularly in regions where standards may not meet global sustainability benchmarks. This article explores the concept of "blood nickel," its implications for the environment and communities, and Canada's potential role in promoting sustainable mining practices.
The Global Nickel Boom
As the automotive industry shifts towards electric vehicles, nickel has emerged as a critical component for lithium-ion batteries due to its ability to store energy efficiently. This surge in demand has led to a global scramble for nickel, with major producers ramping up extraction efforts to meet market needs amid EV shortages and wait times that underscore supply constraints. However, this rapid expansion has raised alarms about the environmental consequences of nickel mining, including deforestation, water pollution, and carbon emissions from energy-intensive extraction processes.
Social Impacts: The Issue of "Blood Nickel"
Beyond environmental concerns, the term "blood nickel" has emerged to describe nickel mined under conditions that exploit workers, disregard human rights, or fail to uphold ethical labor standards. In some regions, nickel mining has been linked to issues such as child labor, unsafe working conditions, and displacement of indigenous communities. This has prompted calls for greater transparency and accountability in global supply chains, with initiatives like U.S.-ally efforts to secure EV metals aiming to align sourcing standards, to ensure that the benefits of EV production do not come at the expense of vulnerable populations.
Canada's Position and Potential
Canada, home to significant nickel deposits, stands at a pivotal juncture in the global EV revolution, supported by EV assembly deals in Canada that strengthen domestic manufacturing. With its robust regulatory framework, commitment to environmental stewardship, and advanced mining technologies, Canada has the potential to lead by example in sustainable nickel mining practices. Canadian companies are already exploring innovations such as cleaner extraction methods, renewable energy integration, and community engagement initiatives to minimize the environmental footprint and enhance social benefits of nickel mining.
Challenges and Opportunities
Despite Canada's potential, the mining industry faces challenges in balancing economic growth with environmental and social responsibility and building integrated supply chains, including downstream investments like a battery plant in Niagara that can connect materials to markets. Achieving sustainable mining practices requires collaboration among governments, industry stakeholders, and local communities to establish clear guidelines, monitor compliance, and invest in responsible resource development. This approach not only mitigates environmental impacts but also fosters long-term economic stability and social well-being in mining regions.
Pathways to Sustainability
Moving forward, Canada can play a pivotal role in shaping the global nickel supply chain by promoting transparency, ethical sourcing, and environmental stewardship. This includes advocating for international standards that prioritize sustainable mining practices, supporting research and development of cleaner technologies, and leveraging adjacent resources such as Alberta lithium potential to diversify battery supply chains, while fostering partnerships with global stakeholders to ensure a fair and equitable transition to a low-carbon economy.
Conclusion
The rapid growth of electric vehicles has propelled nickel into the spotlight, highlighting both its strategic importance and the challenges associated with its extraction. As global demand for "green" metals intensifies, addressing the concept of "blood nickel" becomes increasingly urgent, even as trade measures like tariffs on Chinese EVs continue to reshape market incentives. Canada, with its rich nickel reserves and commitment to sustainability, has an opportunity to lead the charge towards ethical and responsible mining practices. By leveraging its strengths in innovation, regulation, and community engagement, Canada can help forge a path towards a more sustainable future where electric vehicles drive progress without compromising environmental integrity or social justice.
Calgary Winter Energy Usage Surge highlights soaring electricity demand, added megawatt-hours, and grid reliability challenges driven by extreme cold, heating loads, and climate change, with summer air conditioning also shifting seasonal peaks.
Key Points
A spike in Calgary's power use from extreme cold, adding 22k MWh and testing reliability as heating demand rises.
✅ +22,000 MWh vs Feb 2018 amid fourth-coldest February
✅ Heating loads spike; summer A/C now drives peak demand
✅ Grid reliability monitored; more solar and green resources ahead
February was so cold in Calgary that the city used enough extra energy to power 3,400 homes for a whole year, echoing record-breaking demand in B.C. in 2021 during severe cold.
Enmax Power Corporation, the primary electricity utility in the city, says the city 's energy consumption was up 22,000 megawatt hours last month compared with Februray 2018.
"We've seen through this cold period our system has held up very well. It's been very reliable," Enmax vice-president Andre van Dijk told the Calgary Eyeopener on Friday. "You know, in the absence of a windstorm combined with cold temperatures and that sort of thing, the system has actually held up pretty well."
The past month was the fourth coldest in Calgary's history, and similar conditions have pushed all-time high demand in B.C. in recent years across the West. The average temperature for last month was –18.1 C. The long-term average for February is –5.4 C.
Watching use, predicting issues
The electricity company monitors demand and load on a daily basis, always trying to predict issues before they happen, van Dijk said, and utilities have introduced winter payment plans to help customers manage bills during prolonged cold.
One of the issues they're watching is climate change, and how extreme temperatures and weather affect both the grid's reliability, as seen when Quebec shattered consumption records during cold snaps, and the public's energy use.
The colder it gets, the higher you turn up the heat. The hotter it is, the more you use air conditioning.
He also noted that using fuels then contributes to climate change, creating a cycle.
"We are seeing variations in temperature and we've seen large weather events across the continent, across the world, in fact, that impact electrical systems, whether that's flooding, as we've experienced here, or high winds, tornadoes," van Dijk said.
"Climate change and changing weather patterns have definitely had had an impact on us as an electrical industry."
In 2012, he said, Calgary switched from using the most power during winter to using the most during summer, in large part due to air conditioning, he said.
"Temperature is a strong influencer of energy consumption and of our demand," van Dijk said.
Christmas tree lights have also become primarily LED, van Dijk said, which cuts down on a big energy draw in the winter.
He said he expects more solar and other green resources will be added into the electrical system in the future to mitigate how much the increasingly levels of energy use impact climate change, and to help moderate electricity costs in Alberta over time.
Indonesia Coal Production Cuts reflect weaker China demand, COVID-19 impacts, falling HBA reference prices, and DMO sales to PLN, pressuring thermal coal output, miner budgets, and investment plans under the 2020 RKAB.
Key Points
Planned 2020 coal output reductions from China demand slump, lower HBA prices, and DMO constraints impacting miners.
✅ China demand drop reduces exports and thermal coal shipments.
✅ HBA reference price decline pressures margins and cash flow.
✅ DMO sales to PLN limit revenue; investment plans may slow.
The Energy and Mineral Resources (ESDM) Ministry is considering lowering the coal production target this year as demand from China has shown a significant decline, with China power demand drops reported, since the start of the outbreak of the novel coronavirus in the country late last year, a senior ministry official has said.
The ministry’s coal and mineral director general Bambang Gatot Ariyono said in Jakarta on March 12 that the decline in the demand had also caused a sharp drop in coal prices on the world market, and China's plan to reduce coal power has further weighed on sentiment, which could cause the country’s miners to reduce their production.
The 2020 minerals and coal mining program and budget (RKAB) has set a current production goal of 550 million tons of coal, a 10 percent increase from last year’s target. As of March 6, 94.7 million tons of coal had been mined in the country in the year.
“With the existing demand, revision to this year’s production is almost certain,” he said, adding that the drop in demand had also caused a decline in coal prices.
Indonesia’s thermal coal reference price (HBA) fell by 26 percent year-on-year to US$67.08 per metric ton in March, according to a Standards & Poor press release on March 5. At home, the coal price is also unattractive for local producers. Under the domestic market obligation (DMO) policy, miners are required to sell a quarter of their production to state-owned electricity company PLN at a government-set price, even as imported coal volumes rise in some markets. This year’s coal reference price is $70 per metric ton, far below the internal prices before the coronavirus outbreak hit China.
The ministry’s expert staff member Irwandy Arif said China had reduced its coal demand by 200,000 tons so far, as six of its coal-fired power plants had suspended operation due to the significant drop in electricity demand. Many factories in the country were closed as the government tried to halt the spread of the new coronavirus, which caused the decline in energy demand and created electric power woes for international supply chains.
“At present, all mines in Indonesia are still operating normally, while India is rationing coal supplies amid surging electricity demand. But we have to see what will happen in June,” he said.
The ministry predicted that the low demand would also result in a decline in coal mining investment, as clean energy investment has slipped across many developing nations.
The ministry set a $7.6 billion investment target for the mining sector this year, up from $6.17 billion last year, even as Israel reduces coal use in its power sector, which may influence regional demand. The year’s total investment realization was $192 million as of March 6, or around 2.5 percent of the annual target.
US EV Charging Infrastructure is evolving with interoperable NACS and CCS standards, Tesla Supercharger access, federal funding, ultra-fast charging, mobile apps, and battery advances that reduce range anxiety and expand reliable, nationwide fast-charging access.
Key Points
Nationwide network, standards, and funding enabling fast, interoperable EV charging access for drivers across the US.
✅ NACS and CCS interoperability expands cross-network access
✅ Tesla Superchargers opening to more brands accelerate adoption
✅ Federal funding builds fast chargers along highways and communities
The landscape of electric vehicle (EV) charging infrastructure in the United States is rapidly evolving, driven by technological advancements, collaborative efforts between automakers and charging networks across the country, and government initiatives to support sustainable transportation.
Interoperability and Collaboration
Recent developments highlight a shift towards interoperability among charging networks, even as control over charging continues to be contested across the market today. The introduction of the North American Charging Standard (NACS) and the adoption of the Combined Charging System (CCS) by major automakers underscore efforts to standardize charging protocols. This move aims to enhance convenience for EV drivers by allowing them to use multiple charging networks seamlessly.
Tesla's Role and Expansion
Tesla, a trailblazer in the EV industry, has expanded its Supercharger network to accommodate other EV brands. This initiative represents a significant step towards inclusivity, addressing range anxiety and supporting the broader adoption of electric vehicles. Tesla's expansive network of fast-charging stations across the US continues to play a pivotal role in shaping the EV charging landscape.
Government Support and Infrastructure Investment
The federal government's commitment to infrastructure development is crucial in advancing EV adoption. The Bipartisan Infrastructure Law allocates substantial funding for EV charging station deployment along highways and in underserved communities, while automakers plan 30,000 chargers to complement public investment today. These investments aim to expand access to charging infrastructure, promote economic growth, and reduce greenhouse gas emissions associated with transportation.
Technological Advancements and User Experience
Technological innovations in EV charging, including energy storage and mobile charging solutions, continue to improve user experience and efficiency. Ultra-fast charging capabilities, coupled with user-friendly interfaces and mobile apps, simplify the charging process for consumers. Advancements in battery technology also contribute to faster charging times and increased vehicle range, enhancing the practicality and appeal of electric vehicles.
Challenges and Future Outlook
Despite progress, challenges remain in scaling EV charging infrastructure to meet growing demand. Issues such as grid capacity constraints are coming into sharp focus, alongside permitting processes and funding barriers that necessitate continued collaboration between stakeholders. Addressing these challenges is crucial in supporting the transition to sustainable transportation and achieving national climate goals.
Conclusion
The evolution of EV charging infrastructure in the United States reflects a transformative shift towards sustainable mobility solutions. Through interoperability, government support, technological innovation, and industry collaboration, stakeholders are paving the way for a robust and accessible charging ecosystem. As investments and innovations continue to shape the landscape, and amid surging U.S. EV sales across 2024, the trajectory of EV infrastructure development promises to accelerate, ensuring reliable and widespread access to charging solutions that support a cleaner and greener future.
Wave Energy Converters can deliver marine power to the grid, with DOE-backed PacWave enabling offshore testing, robust designs, and renewable electricity from oscillating waves to decarbonize coastal communities and replace diesel in remote regions.
Key Points
Wave energy converters are devices that transform waves' oscillatory motion into electricity for the grid or loads.
✅ Multiple designs convert oscillating motion into torque and power.
✅ Ideal for islands, microgrids, and replacing diesel generation.
Waves off the coast of the U.S. could generate 2.64 trillion kilowatt hours of electricity per year — that’s about 64% of last year’s total utility-scale electricity generation in the U.S. We won’t need that much, but one day experts do hope that wave energy will comprise about 10-20% of our electricity mix, alongside other marine energy technologies under development today.
“Wave power is really the last missing piece to help us to transition to 100% renewables, ” said Marcus Lehmann, co-founder and CEO of CalWave Power Technologies, one of a number of promising startups focused on building wave energy converters.
But while scientists have long understood the power of waves, it’s proven difficult to build machines that can harness that energy, due to the violent movement and corrosive nature of the ocean, combined with the complex motion of waves themselves, even as a recent wave and tidal market analysis highlights steady advances.
″Winds and currents, they go in one direction. It’s very easy to spin a turbine or a windmill when you’ve got linear movement. The waves really aren’t linear. They’re oscillating. And so we have to be able to turn this oscillatory energy into some sort of catchable form,” said Burke Hales, professor of cceanography at Oregon State University and chief scientist at PacWave, a Department of Energy-funded wave energy test site off the Oregon Coast. Currently under construction, PacWave is set to become the nation’s first full-scale, grid-connected test facility for these technologies, a milestone that parallels U.K. wind power lessons on scaling new industries, when it comes online in the next few years.
“PacWave really represents for us an opportunity to address one of the most critical barriers to enabling wave energy, and that’s getting devices into the open ocean,” said Jennifer Garson, Director of the Water Power Technologies Office at the U.S. Department of Energy.
At the beginning of the year, the DOE announced $25 million in funding for eight wave energy projects to test their technology at PacWave, as offshore wind forecasts underscore the growing investor interest in ocean-based energy. We spoke with a number of these companies, which all have different approaches to turning the oscillatory motion of the waves into electrical power.
Different approaches Of the eight projects, Bay Area-based CalWave received the largest amount, $7.5 million.
″The device we’re testing at PacWave will be a larger version of this,” said Lehmann. The x800, our megawatt-class system, produces enough power to power about 3,000 households.”
CalWave’s device operates completely below the surface of the water, and as waves rise and fall, surge forward and backward, and the water moves in a circular motion, the device moves too. Dampers inside the device slow down that motion and convert it into torque, which drives a generator to produce electricity, a principle mirrored in some wind energy kite systems as they harvest aerodynamic forces.
“And so the waves move the system up and down. And every time it moves down, we can generate power, and then the waves bring it back up. And so that oscillating motion, we can turn into electricity just like a wind turbine,” said Lehmann.
Another approach is being piloted by Seattle-based Oscilla Power, which was awarded $1.8 million from the DOE, and is getting ready to deploy its wave energy converter off the coast of Hawaii, at the U.S. Navy Wave Energy Test site.
Oscilla Power’s device is composed of two parts. One part floats on the surface and moves with the waves in all directions — up and down, side to side and rotationally. This float is connected to a large, ring-shaped structure which hangs below the surface, and is designed to stay relatively steady, much like how underwater kites leverage a stable reference to generate power. The difference in motion between the float and the ring generates force on the connecting lines, which is used to rotate a gearbox to drive a generator.
″The system that we’re deploying in Hawaii is what we call the Triton-C. This is a community-scale system,” said Balky Nair, CEO of Oscilla Power. “It’s about a third of the size of our flagship product. It’s designed to be 100 kilowatt rated, and it’s designed for islands and small communities.”
Nair is excited by wave energy’s potential to generate electricity in remote regions, which currently rely on expensive and polluting diesel imports to meet their energy needs when other renewables aren’t available, and similar tidal energy for remote communities efforts in Canada point to viable models. Before wave energy is adopted at-scale, many believe we’ll see wave energy replacing diesel generators in off-the-grid communities.
A third company, C-Power, based in Charlottesville, Virginia, was awarded more than $4 million to test its grid-scale wave energy converter at PacWave. But first, the company wants to commercialize its smaller scale system, the SeaRAY, which is designed for lower-power applications.
″Think about sensors in the ocean, research, metocean data gathering, maybe it’s monitoring or inspection,” said C-Power CEO Reenst Lesemann on the initial applications of his device.
The SeaRAY consists of two floats and a central body, the nacelle, which contains the drivetrain. As waves pass by, the floats bob up and down, rotating about the nacelle and turning their own respective gearboxes which power the electric generators.
Eventually, C-Power plans to scale up its SeaRAY so that it’s capable of satellite communications and deep water deployments, before building a larger system, called the StingRAY, for terrestrial electricity generation.
Meanwhile, one Swedish company, Eco Wave Power, is taking another approach completely, eschewing offshore technologies in favor of simpler wave power devices that can be installed on breakwaters, piers, and jetties.
“All the expensive conversion machinery, instead of being inside the floaters like in the competing technologies, is on land just like a regular power station. So basically this enables a very low installation, operation, and maintenance cost,” explained CEO Inna Braverman.
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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