The lights may burn long into the night in the U.S. House of Representatives office complex and the Capitol in Washington in coming months, but they just might be energy-efficient lights, thanks to the work of a team of Lawrence Berkeley National Laboratory scientists.
Not long after the Democrats took control of the House, Speaker Nancy Pelosi, perhaps in a not-so-subtle dig at the hands-off global-warming policies of the Bush administration, asked for a survey to find out what it would take to "green" House offices — that is, to modernize and streamline the buildings so they would have zero impact on the environment.
For technical help, Chief Administrative Officer Daniel Beard turned to Lawrence Berkeley, which has long had a reputation for unbiased, energy efficiency research.
The House office complex, which includes the House portion of the Capitol building, is an energy hog, clogged with obsolete appliances, electricity-sucking overhead lighting and leaky air conditioning and heating ducts. Worse, much of the electricity comes from high-polluting, coal-fired utility generators.
Evan Mills, leader of one Lawrence Berkeley team on the project, found the complex emitted about 91,000 tons of carbon dioxide in 2006, about the same amount as from 17,200 cars in a single year.
One easy recommendation: Change the lights. Swap energy-hungry incandescent lights for efficient, compact fluorescent lamps. That would be the equivalent of removing 255 cars from the road and result in $245,000 a year in energy savings, lab scientist Francis Rubinstein discovered.
Changing light bulbs is relatively easy. From there on it gets stickier.
Christopher Payne, the lab's principle research associate in Washington, who shepherded the report, explains that many of the house buildings are old. The Capitol is more than 200 years old; the Cannon House Office Building was built in 1908; and the Rayburn House Office Building was finished in 1965.
"These buildings are examples of what I would call 'federal monumental architecture,'" Payne said. "They're big, solid — this is the seat of power — buildings with very high ceilings and thick walls."
Recommendations, besides light bulbs, include:
-Shift to 100 percent renewable electric power. The House uses about 103,000 megawatts of power a year and renewable power would cost about 20 percent more, but eliminate 57,000 tons of greenhouse gas emissions a year, like removing 11,000 cars from the road.
-Install an ethanol tank and fueling pump and switch official House vehicles to ethanol within the next six months.
House vehicles may chug around on ethanol fairly soon, but don't look for solar panels to sprout on House rooftops anytime soon, Payne said. "There are 19 different agencies with authority over changes to buildings in the federal core and some of them have veto power," he said.
But the House is very interested in doing something soon, he said. It wants the changes accomplished before the end of the 110th Congress in 2008, he said.
There's another bottom line item in the report. Even after taking all possible practical steps to cut polluting carbon emissions, the complex will still emit carbon dioxide.
UK Offshore Wind Expansion will make wind the main power source, driving renewable energy, offshore projects, smart grids, battery storage, and interconnectors to cut carbon emissions, boost exports, and attract global investment.
Key Points
A UK strategy to scale offshore wind, integrate smart grids and storage, cut emissions and drive investment and exports
✅ 30% energy target by 2030, backed by CfD support
✅ 250m industry investment and smart grid build-out
✅ Battery storage and interconnectors balance intermittency
Plans are afoot to make wind the UKs main power source for the first time in history amid ambitious targets to generate 30 percent of its total energy supply by 2030, up from 8 percent at present.
A recently inked deal will see the offshore wind industry invest 250 million into technology and infrastructure over the next 11 years, with the government committing up to 557 million in support, under a renewable energy auction that boosts wind and tidal projects, as part of its bid to lower carbon emissions to 80 percent of 1990 levels by 2050.
Offshore wind investment is crucial for meeting decarbonisation targets while increasing energy production, says Dominic Szanto, Director, Energy and Infrastructure at JLL. The governments approach over the last seven years has been to promise support to the industry, provided that cost reduction targets were met. This certainty has led to the development of larger, more efficient wind turbines which means the cost of offshore wind energy is a third of what it was in 2012.
Boosting the wind industry
Offshore wind power has been gathering pace in the UK and has grown despite COVID-19 disruptions in recent years. Earlier this year, the Hornsea One wind farm, the worlds largest offshore generator which is located off the Yorkshire coast, started producing electricity. When fully operational in 2020, the project will supply energy to over a million homes, and a further two phases are planned over the coming decade.
Over 10 gigawatts of offshore wind either already has government support or is eligible to apply for it in the near future, following a 10 GW contract award that underscores momentum, representing over 30 billion of likely investment opportunities.
Capital is coming from European utility firms and increasingly from Asian strategic investors looking to learn from the UKs experience. The attractive government support mechanism means banks are keen to lend into the sector, says Szanto.
New investment in the UKs offshore wind sector will also help to counter the growing influence of China. The UK is currently the worlds largest offshore wind market, but by 2021 it will be outstripped by China.
Through its new deal, the government hopes to increase wind power exports fivefold to 2.6 billion per year by 2030, with the UKs manufacturing and engineering skills driving projects in growth markets in Europe and Asia and in developing countries supported by the World Bank support through financing and advisory programs.
Over the next two decades, theres a massive opportunity for the UK to maintain its industry leading position by designing, constructing, operating and financing offshore wind projects, says Szanto. Building on projects such as the Hywind project in Scotland, it could become a major export to countries like the USA and Japan, where U.S. lessons from the U.K. are informing policy and coastal waters are much deeper.
Wind-powered smart grids
As wind power becomes a major contributor to the UKs energy supply, which will be increasingly made up of renewable sources in coming decades, there are key infrastructure challenges to overcome.
A real challenge is that the UKs power generation is becoming far more decentralised, with smaller power stations such as onshore wind farms and solar parks and more prosumers residential houses with rooftop solar coupled with a significant rise in intermittent generation, says Szanto. The grid was never designed to manage energy use like that.
One potential part of the solution is to use offshore wind farms in other sites in European waters.
By developing connections between wind projects from neighbouring countries, it will create super-grids that will help mitigate intermittency issues, says Szanto.
More advanced energy storage batteries will also be key for when less energy is generated on still days. There is a growing need for batteries that can store large amounts of energy and smart technology to discharge that energy. Were going through a revolution where new technology companies are working to enable a much smarter grid.
Future smart grids, based on developing technology such as blockchain, might enable the direct trading of energy between generators and consumers, with algorithms that can manage many localised sources and, critically, ensure a smooth power supply.
Investors seeking a higher-yield market are increasingly turning to battery technology, Szanto says. In a future smart grid, for example, batteries could store electricity bought cheaply at low-usage times then sold at peak usage prices or be used to provide backup energy services to other companies.
Majors investing in the transition
Its not just new energy technology companies driving change; established oil and gas companies are accelerating spending on renewable energy. Shell has committed to $1-2 billion per year on clean energy technologies out of a $25-30 billion budget, while Equinor plans to spend 15-20 percent of its budget on renewables by 2030.
The oil and gas majors have the global footprint to deliver offshore wind projects in every country, says Szanto. This could also create co-investment opportunities for other investors in the sector especially as nascent wind markets such as the U.S., where the U.S. offshore wind timeline is still developing, and Japan evolve.
European energy giants, for example, have bid to build New Yorks first offshore wind project.
As offshore wind becomes a globalised sector, with a trillion-dollar market outlook emerging, the major fuel companies will have increasingly large roles. They have the resources to undertake the years-long, cost-intensive developments of wind projects, driven by a need for new business models as the world looks beyond carbon-based fuels, says Szanto.
Oil and gas heavyweights are also making wind, solar and energy storage acquisitions BP acquired solar developer Lightsource and car-charging network Chargemaster, while Shell spent $400 million on solar and battery companies.
The public perception is that renewable energy is niche, but its now a mainstream form of energy generation., concludes Szanto.
Every nation in the world is aligned in wanting a decarbonised future. In terms of electricity, that means renewable energy and for offshore wind energy, the outlook is extremely positive.
U.S. Energy Transition Delays stem from grid bottlenecks, permitting red tape, solar tariff uncertainty, supply-chain shocks, and scarce affordable EVs, risking deeper fossil fuel lock-in despite climate targets for renewables, transmission expansion, and decarbonization.
Key Points
Delays driven by grid limits, permitting, and supply shocks that slow renewables, transmission, EVs, and decarbonization.
✅ Grid interconnection and transmission backlogs stall renewables
✅ Tariff probes and supply chains disrupt utility-scale solar
✅ Permitting, policy gaps, and EV costs sustain fossil fuel use
Big solar projects are facing major delays. Plans to adapt the grid to clean energy are confronting mountains of red tape. Affordable electric vehicles are in short supply.
The United States is struggling to squeeze opportunity out of an energy crisis that should have been a catalyst for cleaner, domestically produced power. After decades of putting the climate on the back burner, the country is finding itself unprepared to seize the moment and at risk of emerging from the crisis even more reliant on fossil fuels.
10 steps you can take to lower your carbon footprint The problem is not entirely unique to the United States. Across the globe, climate leaders are warning that energy shortages including coal and nuclear disruptions prompted by Russia’s unprovoked invasion of Ukraine and high gas prices driven by inflation threaten to make the energy transition an afterthought — potentially thwarting efforts to keep global temperature rise under 1.5 degrees Celsius.
“The energy crisis exacerbated by the war in Ukraine has seen a perilous doubling down on fossil fuels by the major economies,” U.N. Secretary General António Guterres said at a conference in Vienna on Tuesday, according to prepared remarks. He warned governments and investors that a failure to immediately and more aggressively embrace clean energy could be disastrous for the planet.
U.S. climate envoy John F. Kerry suggested that nations are falling prey to a flawed logic that fossil fuels will help them weather this period of instability, undermining U.S. national security and climate goals, which has seen gas prices climb to a record-high national average of $5 per gallon. “You have this new revisionism suggesting that we have to be pumping oil like crazy, and we have to be moving into long-term [fossil fuel] infrastructure building,” he said at the Time100 Summit in New York this month. “We have to push back.”
Climate envoy John F. Kerry attends the Summit of the Americas in Los Angeles on June 8. Kerry has criticized the tendency to turn toward fossil fuels in times of uncertainty. (Apu Gomes/AFP/Getty Images) In the United States — the world’s second-largest emitter of greenhouse gases after China — the hurdles go beyond the supply-chain crisis and sanctions linked to the war in Ukraine. The country’s lofty goals for all carbon pollution to be gone from the electricity sector by 2035 and for half the cars sold to be electric by 2030 are jeopardized by years of neglect of the electrical grid, regulatory hurdles that have set projects back years, and failures by Congress and policymakers to plan ahead. The challenges are further compounded by plans to build costly new infrastructure for drilling and exporting natural gas that will make it even harder to transition away from the fossil fuel.
“We are running into structural challenges preventing consumers and businesses from going cleaner, even at this time of high oil and gas prices,” said Paul Bledsoe, a climate adviser in the Clinton administration who now works on strategy at the Progressive Policy Institute, a center-left think tank. “It is a little alarming that even now, Congress is barely talking about clean energy.”
Consumers are eager for more wind and solar. Companies looking to go carbon-neutral are facing growing waitlists for access to green energy, and a Pew Research Center poll in late January found that two-thirds of Americans want the United States to prioritize alternative energy over fossil fuel production.
But lawmakers have balked for more than a decade at making most of the fundamental economic and policy changes such as a clean electricity standard that experts widely agree are crucial to an orderly and accelerated energy transition. The United States does not have a tax on carbon, nor a national cap-and-trade program that would reorient markets toward lowering emissions. The unraveling in Congress of President Biden’s $1.75 trillion Build Back Better plan has added to the head winds that green-energy developers face, even as climate law results remain mixed.
Vice President Harris tours electric school buses at Meridian High School in Falls Church, Va., on May 20. (Mandel Ngan/AFP/Getty Images) “There is literally nothing pushing this forward in the U.S. beyond the tax code and some state laws,” said Heather Zichal, a former White House climate adviser who is now the chief executive of the American Clean Power Association.
The effects of the U.S. government’s halting approach are being felt by solar-panel installers, who saw the number of projects in the most recent quarter fall to the lowest level since the pandemic began. There was 24 percent less solar installed in the first quarter of 2022 than in the same quarter of 2021.
The holdup largely stems from a Commerce Department investigation into alleged tariff-dodging by Chinese manufacturers. Faced with the potential for steep retroactive penalties, hundreds of industrial-scale solar projects were frozen in early April. Weak federal policies to encourage investment in solar manufacturing left American companies ill-equipped to fill the void.
“We shut down multiple projects and had to lay off dozens of people,” said George Hershman, chief executive of SOLV Energy, which specializes in large solar installations. SOLV, like dozens of other solar companies, is now scrambling to reassemble those projects after the administration announced a pause of the tariffs.
Meanwhile, adding clean electricity to the aging power grid has become an increasingly complicated undertaking, given the failure to plan for adequate transmission lines and long delays connecting viable wind and solar projects to the electricity network.
Drax Biomass Conversion accelerates renewable energy by replacing coal with wood pellets, sustainable forestry feedstock, and piloting carbon capture and storage, supporting the UK grid, emissions cuts, and a net-zero pathway.
Key Points
Drax Biomass Conversion is Drax's shift from coal to biomass with CCS pilots to cut emissions and aid UK's net-zero.
✅ Coal units converted to biomass wood pellets
✅ Sourced from sustainable forestry residues
✅ CCS pilots target lifecycle emissions cuts
A power station that used to be the biggest polluter in western Europe has made a near-complete switch to renewable energy, mirroring broader shifts as Denmark's largest energy company plans to end coal by 2023.
The Drax Power Station in Yorkshire, England, used to spew out millions of tons of carbon dioxide a year by burning coal. But over the past eight years, it has overhauled its operations by converting four of its six coal-fired units to biomass. The plant's owners say it now generates 15% of the country's renewable power, as Britain recently went a full week without coal power for the first time.
The change means that just 6% of the utility's power now comes from coal, as the wider UK coal share hits record lows across the national electricity system. The ultimate goal is to stop using coal altogether.
"We've probably reduced our emissions more than any other utility in the world by transforming the way we generate power," Will Gardner, CEO of the Drax Group, told CNN Business.
Subsidies have helped finance the switch to biomass, which consists of plant and agricultural matter and is viewed as a promising substitute for coal, and utilities such as Nova Scotia Power are also increasing biomass use. Last year, Drax received £789 million ($1 billion) in government support.
Is biomass good for the environment?
While scientists disagree over the extent to which biomass as a fuel is environmentally friendly, and some environmentalists urge reducing biomass use amid concerns about lifecycle emissions, Drax highlights that its supplies come from from sustainably managed and growing forests.
Most of the biomass used by Drax consists of low-grade wood, sawmill residue and trees with little commercial value from the United States. The material is compressed into sawdust pellets.
Gardner says that by purchasing bits of wood not used for construction or furniture, Drax makes it more financially viable for forests to be replanted. And planting new trees helps offset biomass emissions.
Forests "absorb carbon as they're growing, once they reach maturity, they stop absorbing carbon," said Raphael Slade, a senior research fellow at Imperial College London.
But John Sterman, a professor at MIT's Sloan School of Management, says that in the short term burning wood pellets adds more carbon to the atmosphere than burning coal.
That carbon can be absorbed by new trees, but Sterman says the process can take decades.
"If you're looking at five years, [biomass is] not very good ... If you're looking at a century-long time scale, which is the sort of time scale that many foresters plan, then [biomass] can be a lot more beneficial," says Slade.
Carbon capture
Enter carbon capture and storage technology, which seeks to prevent CO2 emissions from entering the atmosphere and has been touted as a possible solution to the climate crisis.
Drax, for example, is developing a system to capture the carbon it produces from burning biomass. But that could be 10 years away.
The Coal King is racing to avoid bankruptcy
The power station is currently capturing just 1 metric ton of CO2 emissions per day. Gardner says it hopes to increase this to 10,000 metric tons per day by the mid to late 2020s.
"The technology works but scaling it up and rolling it out, and financing it, are going to be significant challenges," says Slade.
The Intergovernmental Panel on Climate Change shares this view. The group said in a 2018 report that while the potential for CO2 capture and storage was considerable, its importance in the fight against climate change would depend on financial incentives for deployment, and whether the risks of storage could be successfully managed. These include a potential CO2 pipeline break.
In the United Kingdom, the government believes that carbon capture and storage will be crucial to reaching its goal of achieving net-zero greenhouse gas emissions by 2050, even as low-carbon generation stalled in 2019 according to industry analysis.
It has committed to consulting on a market-based industrial carbon capture framework and in June awarded £26 million ($33 million) in funding for nine carbon capture, usage and storage projects, amid record coal-free generation on the British grid.
Western Denmark Negative Electricity Prices stem from wind energy oversupply, grid congestion, and limited interconnector capacity via Nord Pool and TenneT, underscoring electrification needs, renewable integration, special regulation, and system flexibility.
Key Points
They are sub-zero power prices from wind oversupply, weak interconnectors, low demand, and balancing needs.
✅ Caused by high wind output, low demand, and export bottlenecks
✅ Limited Nord Pool interconnector capacity depresses prices
✅ Special regulation and district heating absorb excess power
A downturn in the cable connection to Norway and Sweden, together with low electricity consumption and high electricity production, has pushed down European electricity prices to a negative level in Western Denmark.
A sign that the electrification of society is urgently needed, says Soren Klinge, head of electricity market at Wind Denmark today.
The heavy winds during the first weekend of July, unlike periods when cheap wind power wanes in the UK, have not only had consequences for the Danes who had otherwise been looking forward to spending their first days at home in the garden or at the beach. It has also pushed down prices in the electricity market to a negative level, which especially the West Danish wind turbine owners have had to notice.
'The electricity market is currently affected by an unfortunate coincidence of various factors that have a negative impact on the electricity price: a reduced export capacity to the other Nordic countries, a low electricity consumption and a high electricity generation, reflecting broader concerns over dispatchable power shortages in Europe today. Unfortunately, the coincidence of these three factors means that the price base falls completely out of the market. This is another sign that the electrification of society is urgently needed, 'explains Soren Klinge, electricity market manager at Wind Denmark.
According to the European power exchange Nord Pool Spot, where UK peak power prices are also tracked, the cable connection to Sweden is expected to return to full capacity from 19 July. The connection between Jutland and Norway is only expected to return to full capacity in early September.
2000 MWh / hour in special regulation
During the windy weather on Monday morning, July 6, up to 2000 MWh / hour was activated at national level in the form of so-called special regulation. Special regulation is the designation that the German system operator TenneT switches off Danish electricity generation at cogeneration plants and wind turbines in order to help with the balancing of the German power system during such events. In addition, electric boilers at the cogeneration plants also contribute by using the electricity from the electricity grid and converting it to district heating for the benefit of Danish homes and businesses.
'The Danish wind turbines are probably the source of most of the special regulation, because there are very few cogeneration units to down-regulate electricity generation. Of course, it is positive to see that we have a high degree of flexibility in the wind-based power system at home. That being said, Denmark does not really get ahead with the green transition, even as its largest energy company plans to stop using coal by 2023, until we are able to raise electricity consumption based on renewable energy.
Ontario Electricity Capacity Gap threatens reliability as IESO forecasts shortfalls from the Pickering shutdown and rapid electrification, requiring new low-emission nuclear generation to meet net-zero targets, maintain baseload, and stabilize the grid.
Key Points
Expected 2030 shortfalls from Pickering closure and electrification, requiring new low-emission nuclear to meet net-zero.
✅ New low-emission nuclear needed to meet net-zero targets
Ontario faces an electricity supply shortage and reliability risks in the next four to eight years and will not meet net-zero objectives without building new low-emission, nuclear generation starting as soon as possible, according to a report released yesterday by the Power Workers' Union (PWU). The capacity needed to fill the expected supply gap will be equivalent to doubling the province's planned nuclear fleet in eight years.
The planned closure of the Pickering nuclear power plant in 2025 and the increase in demand from electrification of the economy are the drivers behind a capacity gap in 2030 of at least 3.6 GW which could widen to as much as 9.5 GW, Electrification Pathways for Ontario to Reduce Emissions, finds. Ontario's Independent Electricity System Operator (IESO) has since 2013 been forecasting a significant gap in the province's electricity supply due the closure of Pickering, but has been underestimating the impact of electrification, the report says.
In addition, the electrification of buildings, transport and industry sectors that will be needed to achieve goals of net-zero emissions by 2050 that being set by the federal government and civil society will see the province's electricity demand increase by at least 130% over current planning forecasts, and potentially by over 190%. Leveraging electricity, natural gas and hydrogen synergies can reduce supply needs, but 55 GW of new electricity capacity, including new large-scale nuclear plants, will still be needed by 2050 - four times Ontario's current nuclear and hydro assets - the report finds.
These findings underscore the urgent need for a paradigm shift in Ontario's electricity planning and procurement process, the authors say, adding that immediate action is needed both to mitigate the system reliability risks and enable the significant societal benefits needed to pursue net-zero objectives. Planning for procurement to replace Pickering's capacity, or to pursue life extension options, must begin as soon as possible.
"Policymakers around the world realise climate change can't be tackled without nuclear. Ontario's nuclear fleet has delivered emissions reductions for over 50 years," PWU President Jeff Parnell said. "In fact, without building new nuclear units, Ontario will miss its emission reduction targets and carbon emissions from electricity generation will rise dramatically, as explored in why Ontario's power could get dirtier today."
"This report clearly shows that Ontario cannot sustain the low-carbon status of its hydro and nuclear-based electricity system, decarbonise its economy and meet its carbon reduction targets without new nuclear or continued operation at Pickering in the near term. Most disturbing is the fact that we are already well behind and needed to start planning for this capacity yesterday," he said.
The six operating Candu reactors at Ontario Power Generation's Pickering plant have been kept in operation to provide baseload electricity during the refurbishment of units at the Darlington and Bruce plants. Currently, the company plans to shut down Pickering units 1 and 4 in 2024 and units 5 to 8 in 2025, even as Ontario moves to refurbish Pickering B to extend life.
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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