It was in this little cliffside village on the Yangtze River that the environmental costs of China's Three Gorges Dam began to add up, a down payment on what experts predict will be billions of dollars and years of struggle to contain the damage.
The first sign was just a crack in the terraced earth, about 10 centimetres wide and 11 metres long, villagers said. But engineers, worried about the potential of a massive landslide, temporarily evacuated most of Miaohe's 250 farmers.
Fearing the hillside would never be safe again, the government started constructing a replacement village on a nearby plateau, blasted out of rock for increased stability.
"This is going to be good," said Han Qinbi, 60, a grizzled peasant, pointing at the spacious new home his family will get next summer.
But what Han saw as good fortune was a bad omen for the Chinese government. Eighteen months after the Three Gorges Dam was opened, clear signs of environmental degradation have started to accumulate along the Yangtze, just as activists had warned.
Among the most troubling have been incidents of geological instability in the soaring gorges that now embrace a reservoir stretching behind the dam.
Local officials acknowledge that dozens of major landslides have been recorded, affecting more than 30 kilometres of riverbank.
The Chinese, after a century of talk about taming the Yangtze, finally realized their Three Gorges dream in May 2006.
From the start, Communist Party officials acknowledged the massive engineering project would entail environmental risks and upset the lives of riverside peasants. An estimated 1.2 million people were moved to make way for backed-up water. But the damage could be controlled, the party and government insisted, and the benefits still would outweigh the dangers.
The $24 billion dam played its assigned role in controlling the river during this summer's flood season. The 2.3-kilometre-wide structure has also dramatically increased China's supply of clean electricity, producing 23.7 billion kilowatt hours in the first half of this year. The reservoir and swollen upstream river waters have given the centre of the country a trouble-free transportation lane.
But the breaking-in period has also shown how vast the environmental damage is likely to be – and how expensive to handle. Lei Hengshun, an engineering professor at Chongqing University who has followed the Three Gorges project since its inception, said it has opened a "bottomless pit" of government expenditures that will go on for decades.
A group of hydraulic engineers and environmentalists reported in March that the overall number of landslides in the area, including small ones, surpassed 4,700, requiring reinforcement or evacuation of 1,000 communities.
Higher and less stable water levels behind the dam, now at almost 150 metres above sea level and scheduled to rise, already have altered pressure bearing on the base of majestic cliff sides, they explained.
Along the cliffside road to Miaohe, about 30 kilometres upstream from the dam, a man with a shovel patiently repaired one such slide on a recent afternoon. Just across the river, on the north bank, a small ferry landing had been buried under another, forcing travellers to climb over a mound of earth to board. Concrete reinforcements have been erected nearby to keep clear both lanes of the main east-west road, along the north bank.
"The negative effects of the dam are starting to appear, one by one," said Wu Dengming, who runs the Green Volunteer League of Chongqing and has long warned about the dam's effect on the river's fragile ecology.
In addition to the landslides, he noted, industrial pollution, fertilizer runoff and waste from Chong- qing and other cities have thickened in the backed-up reservoir waters, just as he and others predicted they would. Downstream, he said, Shanghai has noticed seawater moving inland because of a change in the flow of water carried down the river on its long journey from Tibet to the East China Sea.
Lei, the Chongqing University professor, was among a group of government officials, environmentalists and engineers who warned in September that a "catastrophe" could befall the Yangtze River unless the government faces up to the environmental ills intensified by the dam and takes the costly measures necessary to confront them.
"It cost a lot of money to build the dam, and now it's going to keep on costing a lot of money," Lei said.
UK Wind and Tidal Power Auction signals strong CfD support for offshore wind, tidal stream projects, investor certainty, and clean electricity, accelerating the net-zero transition, boosting jobs, and strengthening UK energy security and grid integration.
Key Points
A CfD auction awarding contracts for wind and tidal projects to scale clean power and advance UK net-zero.
✅ Jobs, investment, and grid integration accelerate
In a significant development for the UK’s renewable energy sector, the latest auction for renewable energy contracts has underscored a transformative shift towards wind and tidal power. As reported by The Guardian, the auction results reveal a strong commitment to expanding these technologies, with new contracts adding 10 GW to the UK grid, marking a pivotal moment in the UK’s transition to cleaner energy sources.
The Auction’s Impact
The renewable energy auction, which took place recently, has allocated contracts for a substantial increase in wind and tidal power projects. This auction, part of the UK’s Contracts for Difference (CfD) scheme, is designed to support the development of low-carbon energy technologies by providing financial certainty to investors. By offering fixed prices for the electricity generated by these projects, the CfD scheme aims to stimulate investment and accelerate the deployment of renewable energy sources.
The latest results are particularly notable for the significant share of contracts awarded to offshore wind farms and tidal power projects, highlighting how offshore wind is powering up the UK as policy and investment priorities continue to shift. This marks a shift from previous auctions, where solar power and onshore wind were the dominant technologies. The move towards supporting offshore wind and tidal power reflects the UK’s strategic focus on harnessing its abundant natural resources to drive the transition to a low-carbon energy system.
Offshore Wind Power: A Major Contributor
Offshore wind power has emerged as a major player in the UK’s renewable energy landscape, within a global market projected to become a $1 trillion business over the coming decades. The recent auction results highlight the continued growth and investment in this sector.
The UK has been a global leader in offshore wind development, with several large-scale projects already operational and more in the pipeline. The auction has further cemented this position, underscoring what the U.S. can learn from the U.K. in scaling offshore wind capacity, with new projects set to contribute significantly to the country’s renewable energy capacity. These projects are expected to deliver substantial amounts of clean electricity, supporting the UK’s goal of achieving net-zero emissions by 2050.
Tidal Power: An Emerging Frontier
Tidal power, although less developed compared to wind and solar, is gaining momentum as a promising renewable energy source, with companies harnessing oceans and rivers to demonstrate practical potential. The auction results have allocated contracts to several tidal power projects, signaling growing recognition of the potential of this technology.
Tidal power harnesses the energy from tidal movements and currents, which are highly predictable and consistent, and a market outlook for wave and tidal energy points to emerging growth drivers and investment. This makes it a reliable complement to intermittent sources like wind and solar power. The inclusion of tidal power projects in the auction reflects the UK’s commitment to diversifying its renewable energy portfolio and exploring all available options for achieving energy security and sustainability.
Economic and Environmental Benefits
The expansion of wind and tidal power projects through the recent auction offers numerous economic and environmental benefits. From an economic perspective, these projects are expected to create thousands of jobs in construction, maintenance, and manufacturing. They also stimulate investment in local economies and support the growth of the green technology sector.
Environmentally, the increased deployment of wind and tidal power contributes to significant reductions in greenhouse gas emissions. Offshore wind farms and tidal power projects produce clean electricity with minimal environmental impact, helping to mitigate the effects of climate change and improve air quality.
Challenges and Future Outlook
Despite the positive outcomes of the auction, there are challenges to address. Offshore wind farms and tidal power projects require substantial upfront investment and face technical and logistical challenges. Issues such as grid integration, environmental impact assessments, and supply chain constraints need to be carefully managed to ensure the successful deployment of these projects.
Looking ahead, the UK’s renewable energy strategy will continue to evolve as new technologies and innovations emerge, and growth despite Covid-19 underscores sector resilience. The success of the latest auction demonstrates the growing confidence in wind and tidal power and sets the stage for further advancements in renewable energy.
The UK government’s commitment to supporting these technologies through initiatives like the CfD scheme is crucial for achieving long-term energy and climate goals. As the country progresses towards its net-zero target, the continued expansion of wind and tidal power will play a key role in shaping a sustainable and resilient energy future.
Conclusion
The latest renewable energy auction represents a significant milestone in the UK’s transition to a low-carbon energy system. By awarding contracts to wind and tidal power projects, the auction underscores the country’s commitment to harnessing diverse and reliable sources of renewable energy. The expansion of offshore wind and the emerging role of tidal power highlight the UK’s strategic approach to achieving energy security, reducing emissions, and driving economic growth. As the renewable energy sector continues to evolve, the UK remains at the forefront of global efforts to build a sustainable and clean energy future.
Ontario Electricity Supply Gap threatens growth as demand from EVs, heat pumps, industry, and greenhouses surges, pressuring the grid and IESO to add nuclear, renewables, storage, transmission, and imports while meeting net-zero goals.
Key Points
The mismatch as Ontario's electricity demand outpaces supply, driven by electrification, EVs, and industrial growth.
✅ Demand growth from EVs, heat pumps, and electrified industry
✅ Capacity loss from Pickering retirement and Darlington refurb
Ontario electricity demand is forecast to soon outstrip supply as it confronts a shortage in the coming years, a problem that needs attention in the upcoming provincial election.
Forecasters say Ontario will need to double its power supply by 2050 as industries ramp up demand for low-emission clean power options and consumers switch to electric vehicles and space heating. But while the Ford government has made a flurry of recent energy announcements, including a hydrogen project at Niagara Falls and an interprovincial agreement on small nuclear reactors, it has not laid out how it intends to bulk up the province’s power supply.
“Ontario is entering a period of widening electricity shortfalls,” says the Ontario Chamber of Commerce. “Having a plan to address those shortfalls is essential to ensure businesses can continue investing and growing in Ontario with confidence.”
The supply and demand mismatch is coming because of brisk economic growth combined with increasing electrification to balance demand and emissions and meet Canada’s goal to reduce CO2 emissions by 40 per cent by 2030 and to net-zero by 2050.
Hamilton’s ArcelorMittal Dofasco and Algoma Steel in Sault Ste. Marie are leaders on this transformation. They plan to replace their blast furnaces and basic oxygen furnaces later this decade with electric arc furnaces (EAFs), reducing annual CO2 emissions by three million tonnes each.
Dofasco, which operates an EAF that is already the single largest electricity user in Ontario, plans to build a second EAF and a gas-fired ironmaking furnace, which can also be powered with zero-carbon hydrogen produced from electricity, once it becomes available.
Other new projects in the agriculture, mining and manufacturing sectors are also expected to be big power users, including the recently announced $5 billion Stellantis-LG electric vehicle battery plant in Windsor. Five new transmission lines will be built to service the plant and the burgeoning greenhouse industry in southwestern Ontario. The greenhouses alone will require enough additional electricity to power a city the size of Ottawa.
On top of these demands, growing numbers of Ontario drivers are expected to switch to electric vehicles and many homeowners and business owners are expected to convert from gas heating to heat pumps and electric heating.
Ontario is recognized as one of the cleanest electricity systems in the world, with over 90 per cent of its capacity from low-emission nuclear, hydro, wind and other renewable generation. Only nine per cent comes from CO2-emitting gas plants. But that’s about to get dirtier according to analysts.
Annual electricity demand is expected to grow from 140 terawatt hours (a terawatt hour is one trillion watts for one hour) currently to about 200 terawatt hours in 2042, according to the Independent Electricity System Operator, the agency that manages Ontario’s grid.
Demand is expected to outstrip currently contracted supply in 2026, reaching a growing supply gap of about 80 terawatt hours by 2042. A big part of this gap is due to the scheduled retirement of the Pickering nuclear station in 2025 and the current refurbishment of the Darlington nuclear station reactors. While the IESO doesn’t expect blackouts or brownouts, it forecasts the province will need to sharply increase expensive power imports and triple the amount of CO2-polluting gas-fired generation.
Without cleaner, lower-cost alternatives, this will mean “a vastly dirtier and more expensive electricity system,” York University researchers Mark Winfield and Collen Kaiser said in a recent commentary.
The party that wins the provincial election will have to make hard decisions on renewable energy, including new wind and solar projects, energy conservation, battery storage, new hydro plants, small nuclear reactors, gas generation and power imports from the U.S. and Quebec. In addition, the federal government is pressing the provinces to meet a new net-zero clean electricity standard by 2035. These decisions will have huge impact on Ontario’s future, with greening the grid costs highlighted in some reports as potentially very high.
With so much at stake, Ontario’s political parties need to tell voters during the upcoming campaign how they would address these enormous challenges.
Enel Green Power España Aragon wind farms advance Spain's renewable energy transition, with 90MW under construction in Teruel, Endesa investment of €88 million, 25-50MW turbines, and 2017 auction-backed capacity enhancing grid integration and clean power.
Key Points
They are three Teruel wind projects totaling 90MW, part of Endesa's 2017-awarded plan expanding Spain's clean energy.
✅ 90MW across Sierra Costera I, Allueva, and Sierra Pelarda
✅ €88m invested; 14+7+4 turbines; Endesa-led build in Teruel
✅ Part of 2017 tender: 540MW wind, 339MW solar, nationwide
Enel Green Power Espana, part of Enel's wind projects worldwide, has started constructing three wind farms in Aragon, north-east Spain, which are due online by the end of the year.
The projects, all situated in the Teruel province, are worth a total investment of €88 million.
The biggest of the facilities, Sierra Costera I, will have a 50MW and will feature 14 turbines.
The wind farm is spread across the municipalities of Mezquita de Jarque, Fuentes Calientes, Canada Vellida and Rillo.
The Allueva wind facility will feature seven turbines and will exceed 25MW.
Sierra Pelarda, in Fonfria, will have four turbines and a capacity of 15MW, as advances in offshore wind turbine technology continue to push scale elsewhere.
The projects bring the total number of wind farms that Enel Green Power Espana has started building in the Teruel province to six, equal to an overall capacity of 218MW.
Endesa chief executive Jose Bogas said: “These plants mark the acceleration on a new wave of growth in the renewable energy space that Endesa is committed to pursue in the next years, driving the energy transition in Spain.”
The six wind farms under construction in Teruel are part of the 540MW that Enel Green Power Espana was awarded in the Spanish government's renewable energy tender held in May 2017.
In Aragon, the company will invest around €434 million euros, reflecting broader European wind power investment trends in recent years, to build 13 wind farms with a total installed capacity of more than 380MW.
The remaining 160MW of wind capacity will be located in Andalusia, Castile-Leon, Castile La Mancha and Galicia, even as some Spanish turbine factories closed during pandemic restrictions.
Enel Green Power Espana was also awarded 339MW of solar capacity in the Spanish government's auction held in July 2017, while other Spanish developers advance CSP projects abroad in markets like Chile.
Once all wind and solar under the 2017 tender are complete they will boost the company’s capacity by around 52%.
China Power Rationing disrupts the solar supply chain as coal shortages, price controls, and dual-control emissions policy curb electricity, squeezing polysilicon, aluminum, and module production and raising equipment costs amid surging post-Covid industrial demand.
Key Points
China's electricity curbs from coal shortages, price caps, and emissions targets disrupt solar output and materials.
✅ Polysilicon and aluminum output cut by power rationing
✅ Coal price spikes and power price caps squeeze generators
The solar manufacturing supply chain is among the industries being affected by a combination of soaring power demand, coal shortages, and carbon emission reduction measures which have seen widespread power cuts in China.
In Yunnan province, in southwest China, producers of the silicon metal which feeds polysilicon have been operating at 10% of the output they achieved in August. They are expected to continue to do so for the rest of the year as provincial authorities try to control electricity demand with a measure that is also affecting the phosphorus industry.
Fellow solar supply chain members from the aluminum industry in Guangxi province, in the south, have been forced to operate just two days per week, alongside peers in the concrete, steel, lime, and ceramics segments. Manufacturers in neighboring Guangdong have access to normal power supplies only on Fridays and Saturdays with electricity rationed to a 15% grid security load for the rest of the time.
pv magazine USA reported that a Tier 1 solar module manufacturer warned customers in an email that energy shortages in China have forced it to reduce or stop production at its Chinese manufacturing sites. The company warned the event will also affect output from its downstream cell and module production facilities in Southeast Asia.
The memo said that in order to recover from the effects of the “potential Force Majeure event,” it may delay or stop equipment delivery or seek to renegotiate contracts to pass through higher prices.
Raw material sourcing With reports of drastic power shortages emerging from China in recent days, the country has actually been experiencing problems since late June, and similar pressures have seen India ration coal supplies this year, but rationing is not unusual during the peak summer hours.
What has changed this time is that the outages have continued and prompted rationing measures across 19 of the nation’s provinces for the rest of the year. The problems have been caused by a combination of rising post-Covid electricity demand at a time when the politically-motivated ban on imports of Australian coal has tightened supply; and the manner in which Beijing controls power prices, with the situation further exacerbated by carbon emissions reduction policy.
Demand Electricity demand from industry, underscoring China’s electricity appetite, was 13.5 percentage points higher in the first eight months of the year than in the same period of 2020, at 3,585 TWh. That reflected a 13.8% year-on-year rise in total consumption, following earlier power demand drops when coronavirus shuttered plants, to 5.47 PWh, according to data from state energy industry trade body the China Electricity Council.
Figures produced by the China General Administration of Customs tell the same story: a rebound driven by the global recovery from the pandemic, as global power demand surges above pre-pandemic levels, with China recording import and export trade worth RMB2.48 trillion ($385 billion) in January-to-August. That was up 23.7% on the same period of last year and 22.8% higher than in the first eight months of 2019.
With Beijing having enforced an unofficial ban on imports of Australian coal for the last year or so – as the result of an ongoing diplomatic spat with Australia – rising demand for coal (which provided around 73% of Chinese electricity in the first half of the year) has further raised prices for the fossil fuel.
The problem for Chinese coal-fired power generators is that Beijing maintains strict controls on the price of electricity. As a result, input costs cannot be passed on to consumers. The mismatch between a liberalized coal market and centrally controlled end-user prices is illustrated by the current situation in Guangdong. There, a coal price of RMB1,560 per ton ($242) has pushed the cost of coal-fired electricity up to RMB0.472 per kilowatt-hour ($0.073). With coal power companies facing an electricity price ceiling of around RMB0.463/kWh ($0.071), generators are losing around RMB0.12 for every kilowatt-hour they generate. In that situation, rationing electricity supplies is an obvious remedy.
The crisis has been worsened by the introduction of China’s “dual control” energy policy, which aims to help meet President Xi Jinping’s climate change pledge of hitting peak carbon emissions this decade and a net zero economy by 2060, and to reduce coal power production over time. Dual control refers to attempts to wind down greenhouse gas emissions at both a national level and in more local areas, such as provinces and cities.
Red status With the finer details of the carbon reduction policy yet to be ironed out, government departments and provincial and city authorities have started to set their own emission-reduction targets. In mid-August, state planning body the China National Development and Reform Commission (NDRC) published a table of the energy control situation across the nation. With nine provinces marked red for their energy consumption, and a further 10 highlighted as yellow, officials received another motivation to introduce power rationing.
China’s solar industry is being impacted by coal shortages for electric power generation. In this 2014 photo, a thermal generating plant’s cooling towers loom over a street in Henan Province. Image: flickr/V.T. Polywoda
The current approach of rolling blackouts seems unlikely to be a sustainable solution, as surging electricity demand strains power systems worldwide, given the damage it could inflict on industry and the resentment it would cause in parts of the nation already preparing for winter.
The choice facing China’s policymakers is whether to ramp up coal supplies to force prices down by using decommissioned domestic supplies and halting the ban on Australian imports, or to raise electricity prices to prompt generators to get the lights back on. While the drawbacks of raising household electricity bills seem obvious, the first approach of using more coal could endanger the nation’s climate change commitments on the even of the COP26 meeting in Glasgow, Scotland, in November. Sources close to the NDRC have suggested the electricity price may be set to rise soon.
GDP What is clear is the effect the energy crisis is having on the Chinese economy and on the solar supply chain. Leading up to a national day holiday in China, the coal price in northern China rose to around RMB2,000 per ton ($310), three times higher than at the beginning of the year.
Investment bank China International Capital Corp. blamed the dual control emission reduction policy for the electricity shortages. It predicted a 0.1-0.15 percentage point impact on economic growth in the last quarter of 2021. Morgan Stanley has put that figure at 1% in the current quarter, if industrial output restrictions continue. And Japan’s Nomura Securities revised down its annual forecast on Chinese growth from 8.2% to 7.7%. It now expects GDP gains in the third and fourth quarters to cool from 5.1% to 4.7%, and from 4.4% to 3%, respectively.
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.
Daimler Electric Strategy drives EV adoption with global battery factories, Mercedes-Benz electrified models, battery cells procurement, and major investments spanning vans, buses, trucks, and production capacity across Europe, Asia, and the USA.
Key Points
Daimler Electric Strategy is a multi-billion EV roadmap for batteries, factories, and 130 electrified Mercedes models.
✅ Eight battery factories across three continents
✅ EUR 10B for EV lineup; EUR 20B for battery cells
✅ 130 electrified variants plus vans, buses, trucks
Throughout 2018, we all witnessed the unprecedented volume of promises for a better future made by the giants of the auto industry. All say they've committed billions so that, within a decade, combustion engines will be on their way out.
The most active of all companies when talking about promises is Volkswagen, which, amid German plant closures, time and time again has said it will do this or that and completely change the meaning of car in the coming years. But there are other planning the same thing, possibly with even vaster resources.
Planning to end the year on a high note, Daimler detailed its plan for the electric future once again on Tuesday, this time making no secret of its gigantic size and scope.
As announced before, Daimler plans to build electric cars, but also manufacture electric batteries for its own and others’ use, and has launched a US energy storage company to support this strategy. These batteries will eventually be produced by Daimler in eight factories on three continents.
Batteries are already rolling off the lines in Kamenz, and a second facility will begin doing so next year. Two more factories will be built in Stuttgart-Untertürkheim, one at the company’s Sindelfingen site, and one each at the sites in Beijing (China), Bangkok (Thailand) and Tuscaloosa (USA).
In all, one billion EUR will be invested in the expansion of the global battery production network, but that is nothing compared to the 10 billion to be poured into the expansion of the Mercedes-Benz car fleet.
On top of that, 20 billion EUR will go towards the purchase of battery cells from producers all around the world, echoing other automakers' battery sourcing strategies worldwide over the next 12 years.
“After investing billions of euros in the development of the electric fleet and the expansion of our global battery network, we are now taking the next step,” said in a statement Dieter Zetsche, Daimler chairman of the board.
“With the purchase of battery cells for more than 20 billion euros, we are systematically pushing forward with the transformation into the electric future of our company.”
By 2022, the carmaker plans to launch 130 electrified variants of its cars, as cheaper, more powerful batteries become available, adding to them electric vans, buses and trucks. That pretty much means all the models and variants sold by Daimler globally will be at least partially powered by electricity.
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