A new national survey released finds Americans once again prefer aesthetic home improvements – a refinished kitchen or bathroom – over money-saving improvements, such as energy-efficient windows or a high-efficiency furnace.
The survey, the fifth annual Energy Pulse survey conducted by Shelton Group, found that consumers are reverting to their old priorities as the recession wanes – perhaps at the expense of the environment.
“Energy efficiency is back to playing second fiddle, competing with more visible and exciting home improvement projects,” said Suzanne Shelton, whose firm conducted the study. “Anyone selling energy-efficient products must either focus heavily on the aesthetic or comfort aspects of their products or play up their environmental benefits in a big way.”
The survey, which polled 504 Americans by telephone in September, asked consumers: “Assuming you were suddenly given $10,000 to make home improvements, which two of the following would you choose?” The top answers were:
• Refinish the kitchen or bathroom (37 percent);
• Replace carpet or add hardwood or tile (33 percent);
• Replace windows (31 percent);
• Replace HVAC/furnace (23 percent).
Last yearÂ’s top answers were:
• Replace windows (35 percent);
• Replace HVAC/furnace (27 percent);
• Remodel kitchen or bathroom (26 percent);
• Replace carpet or add hardwood or tile (25 percent).
Among the surveyÂ’s other findings:
• Consumers are willing to watch their energy bills go up more than 70 percent, on average, before feeling forced to make energy-efficient home improvements. Respondents said their bills would need to go up an average of $129 a month to make them undertake renovations.
“We call this phenomenon the ‘Apathy Gap,’ the price people are willing to pay to do nothing,” Shelton said. “Here consumers are willing to waste more than $1,500 a year, or more than $4 a day, before they’ll take action. For that same amount, a homeowner could install insulation or purchase one or two new ENERGY STAR appliances to start seeing immediate savings.”
• There is a lot of pent-up demand for solar power. The survey asked, "How likely would you be to buy a solar electricity system for your home, knowing that a mid-size system that would provide around 63 percent of the average household's electricity, costs $35,000 to $40,000 that could be offset by a $2,000 federal tax incentive along with additional rebates in many states.”
• 28 percent said they would be likely or very likely to buy such a system.
• Fewer than 1 percent reported they already had such a system.
“This indicates an enormous potential market for solar,” Shelton said. “Consumers have been waiting for solar to become more accessible and more affordable. Now, with prices projected to fall even further, and with new federal tax incentive greater than they've ever been — up to 30 percent of the cost of the system for qualifying taxpayers — solar power will be on the rise."
• Consumers have good intentions – but not very good follow-through. Surveys over the past five years, including this year, show consistently large discrepancies between intentions and actions. Every year, for example, around 20 percent or more consumers say they’re planning to get an energy audit, yet the percentage of U.S. homeowners who've actually gotten one has languished in the 10-15 percent range.
“That’s why we now refer to home energy audits as the ‘colonoscopy’ of energy efficiency,” Shelton said. “Everyone knows they should get one, but too few actually do.”
Quebec Windstorm 2025 disrupted Montreal and surrounding regions, triggering power outages, Hydro-Québec repairs, fallen trees, infrastructure damage, and transport delays, while emergency response and community resilience accelerated restoration and recovery efforts across the province.
Key Points
A severe April 29 windstorm with 100 km/h gusts caused outages, damage, and emergency recovery across Quebec.
✅ Gusts exceeded 100 km/h across Montreal and nearby regions
✅ Hydro-Québec restored power; crews cleared debris and lines
✅ Communities shared resources, shelters, and volunteer support
A powerful windstorm swept across Quebec on April 29, 2025, leaving tens of thousands of residents without electricity and causing significant damage to infrastructure. The storm's intensity disrupted daily life, leading to widespread outages across the province, fallen trees, and transportation delays.
Storm's Impact
The windstorm, characterized by gusts exceeding 100 km/h, struck various regions of Quebec, including Montreal and its surrounding areas. Hydro-Québec reported extensive power outages affecting numerous customers. The storm's ferocity led to the uprooting of trees, downing of power lines, and significant damage to buildings and vehicles.
Response and Recovery Efforts
In the aftermath, emergency services and utility companies mobilized to restore power and clear debris. Hydro-Québec crews worked tirelessly, much like Sudbury Hydro teams did in Ontario, to repair damaged infrastructure, while municipal authorities coordinated efforts to ensure public safety and facilitate the restoration process. Despite these efforts, some areas experienced prolonged outages, highlighting the storm's severity.
Community Resilience
Residents demonstrated remarkable resilience during the crisis. Many communities came together to support one another, as seen when Toronto neighborhoods rallied during lingering outages, sharing resources and providing assistance to those in need. Local shelters were set up to offer warmth and supplies to displaced individuals, and volunteers played a crucial role in the recovery process.
Lessons Learned
The storm underscored the importance of preparedness and infrastructure resilience, including vulnerabilities highlighted by a recent manhole fire affecting Hydro-Québec customers. In response, discussions have been initiated regarding the strengthening of power grids and the implementation of more robust emergency response strategies to mitigate the impact of future natural disasters.
As Quebec continues to recover, the collective efforts of its residents and emergency services serve as a testament to the province's strength and unity, even as similar strong-wind outages affect other regions, in the face of adversity.
Nordic Power Grid Dispute highlights cross-border interconnector congestion, curtailed exports and imports, hydropower priorities, winter demand spikes, rising spot prices, and transmission grid security amid decarbonization efforts across Sweden, Norway, Finland, and Denmark.
Key Points
A clash over interconnectors and capacity cuts reshaping trade, prices, and reliability in the Nordic power market.
✅ Sweden cuts interconnector capacity to protect grid stability
✅ Norway prioritizes higher-priced exports via new cables
✅ Finland and Denmark seek EU action on capacity curtailments
A spat over electricity supplies is heating up in northern Europe. Sweden is blocking Norway from using its grids to transfer power from producers throughout the region. That’s angered Norway, which in turn has cut flows to its Nordic neighbor.
The dispute has built up around the use of cross-border power cables, which are a key part of Europe’s plans to decarbonize since they give adjacent countries access to low-carbon resources such as wind or hydropower. The electricity flows to wherever prices are higher, informed by how electricity is priced across Europe, without interference from grid operators -- but in the event of a supply squeeze, flows can be stopped.
Sweden moved to safeguard the security of its grid after Norway started increasing electricity exports through huge new cables to Germany and the U.K. Those exports at times have drawn energy away from Sweden, resulting in the country’s system operator cutting capacity at its Nordic borders, preventing exports but also hindering imports, which it relies on to handle demand spikes during winter.
“This is not a good situation in the long run,” Christian Holtz, a energy market consultant for Merlin & Metis AB.
Norway hit back last week by cutting flows to Sweden, this will prioritize better paying customers in Europe, amid Irish price spikes that highlight dispatchable shortages, giving them access to its vast hydro resources at the expense of its Nordic neighbors.
By partially closing its borders Sweden can’t access imports either, which it relies on to handle demand spikes during the coldest days of the winter.
The Swedish grid manager Svenska Kraftnat has reduced export capacity at cables across its borders by as much as half this year to keep operations secure. Finland and Denmark rely on imports too and the cuts will come at a cost for millions of homes and industries across the four nations already contending with record electricity rates this year.
Finland and Denmark want the European Union to end the exemption to regulations that make such reductions possible in the first place, as Europe is losing nuclear power and facing tighter supply.
“Imports from our neighboring countries ensure adequacy at times of peak consumption,” said Reima Paivinen, head of operation at the Finland’s Fingrid. “The recent surge in electricity prices throughout Europe does not directly affect the adequacy of electricity, but prices may rise dramatically for short periods.”
Svenska Kraftnat says it’s not political -- it has no choice but to cut capacity until its old grids are expanded to handle the new direction of flows, a challenge mirrored by grid expansion woes in Germany that slow integration. That could take at least until 2030 to complete, it said earlier this year. At the same time, Norway halving available export capacity to about 1,200 megawatts will increase risk of shortages.
“If we need more we will have to count on imports from other countries,” said Erik Ek, head of strategic operation at Svenska Kraftnat. “If that is not available, we will have to disconnect users the day it gets cold.”
Germany Solar Cap Removal would accelerate photovoltaics, storage, and renewables, replacing coal and nuclear during phaseout with 10GW per year toward 162GW by 2030, boosting grid resilience, O&M jobs, and domestic clean energy growth.
Key Points
A policy change to scrap the 52GW limit, enabling 10GW/year PV and storage to replace coal and nuclear capacity.
✅ Scrap 52GW cap to prevent post-2020 market slump
✅ Create jobs in planning, installation, and O&M through 2030
The German Solar Association (BSW) has called on the government to remove barriers to the development of new solar power capacity in Germany and storage capacity needed to replace coal and nuclear generation that is being phased out.
A 52GW cap should be scrapped, otherwise there is a risk that a market slump will occur in the solar industry after 2020, BSW said, especially as U.S. solar expansion plans signal accelerating global demand.
BSW managing director Carsten Körnig said: “Time is running out, and further delays are irresponsible. The 52GW mark will already be reached within a few months.” A new report from BSW, in cooperation with Bonn-based marketing and social research company EuPD Research and The smarter E Europe initiative, said 10GW a year is needed as well as an increase in battery storage capacity.
This would lead to cumulative photovoltaic capacity of 162GW and 15GW residential, commercial and grid storage systems by 2030, in line with global renewable records being set, leading to new job opportunities.
The number of jobs in the domestic photovoltaic and storage industries could increase to 78,000 by the end of the next decade from today’s level of 26,400, aligning with forecasts of wind and solar reaching 50% by mid-century, said 'The Energy Transition in the Context of the Nuclear and Coal Phaseout – Perspectives in the Electricity Market to 2040' study.
Job growth would take place for the most part in the fields of planning, installation and operations and maintenance of PV systems, as solar uptake in Poland increases, the report said.
In maintenance alone, employment would increase from 9,200 to 26,000, with additional opened up by tapping into the market potential of medium- to long-term storage systems, alongside changing electricity prices in Northern Europe that favor flexibility, it said.
The report added that industry revenue could grow from €5bn to €12.5bn in the coming decade.
The report was supported by BayWa Re E3/DC, Fronius, Goldbeck Solar, IBC Solar, Panasonic, Sharp, Siemens, Sonnen, Suntech, Tesvolt and Varta.
Ontario Energy Storage Procurement accelerates grid flexibility as IESO seeks lithium batteries, pumped storage, compressed air, and flywheels to balance renewables, support EV charging, and complement gas peakers during Pickering refits and rising electricity demand.
Key Points
Ontario's plan to procure 2,500 MW of storage to firm renewables, aid EV charging, and add flexible grid capacity.
✅ 2,500 MW storage plus 1,500 MW gas for 2025-2027 reliability
✅ Enables VPPs via EVs, demand response, and hybrid solar-storage
Ontario is staring down an electricity supply crunch and amid a rush to secure more power, it is plunging into the world of energy storage — a relatively unknown solution for the grid that experts say could also change energy use at home.
Beyond the sprawling nuclear plants and waterfalls that generate most of the province’s electricity sit the batteries, the underground caverns storing compressed air to generate electricity, and the spinning flywheels waiting to store energy at times of low demand and inject it back into the system when needed.
The province’s energy needs are quickly rising, with the proliferation of electric vehicles and growing Canada-U.S. collaboration on EV adoption, and increasing manufacturing demand for electricity on the horizon just as a large nuclear plant that supplies 14 per cent of Ontario’s electricity is set to be retired and other units are being refurbished.
The government is seeking to extend the life of the Pickering Nuclear Generating Station, planning an import agreement for power with Quebec, rolling out conservation programs, and — controversially — relying on more natural gas to fill the looming gap between demand and supply, amid Northern Ontario sustainability debates.
Officials with the Independent Electricity System Operator say a key advantage of natural gas generation is that it can quickly ramp up and down to meet changes in demand. Energy storage can provide that same flexibility, those in the industry say.
Energy Minister Todd Smith has directed the IESO to secure 1,500 megawatts of new natural gas capacity between 2025 and 2027, along with 2,500 megawatts of clean technology such as energy storage that can be deployed quickly, which together would be enough to power the city of Toronto.
It’s a far cry from the 54 megawatts of energy storage in use in Ontario’s grid right now.
Smith said in an interview that it’s the largest active procurement for energy storage in North America.
“The one thing that we want to ensure that we do is continue to add clean generation as much as possible, and affordable and clean generation that’s reliable,” he said.
Rupp Carriveau, director of the Environmental Energy Institute at the University of Windsor, said the timing is good.
“The space is there, the technology is there, and the willingness among private industry to respond is all there,” he said. “I know of a lot of companies that have been rubbing their hands together, looking at this potential to construct storage capacity.”
Justin Rangooni, the executive director of Energy Storage Canada, said because of the relatively tight timelines, the 2,500 megawatts is likely to be mostly lithium batteries. But there are many other ways to store energy, other than a simple battery.
“As we get to future procurements and as years pass, you’ll start to see possibly pump storage, compressed air, thermal storage, different battery chemistry,” he said.
Pump storage involves using electricity during off-peak periods to pump water into a reservoir and slowly releasing it to run a turbine and generate electricity when it’s needed. Compressed air works similarly, and old salt caverns in Goderich, Ont., are being used to store the compressed air.
In thermal storage, electricity is used to heat water when demand is low and when it’s needed, water stored in tanks can be used as heat or hot water.
Flywheels are large spinning tops that can store kinetic energy, which can be used to power a turbine and produce electricity. A flywheel facility in Minto, Ont., also installed solar panels on its roof and became the first solar storage hybrid facility in Ontario, said a top IESO official.
Katherine Sparkes, the IESO’s director of innovation, research and development, said it’s exciting, from a grid perspective.
“As we kind of look to the future and we think about gas phase out and electrification, one of the big challenges that all power systems across North America and around the world are looking at is: how do you accommodate increasing amounts of variable, renewable resources and just make better use of your grid assets,” she said.
“Hybrids, storage generation pairings, gives you that opportunity to deal with the variability of renewables, so to store electricity when the sun isn’t shining, or the wind isn’t blowing, and use it when you need it to.”
The small amount of storage already in the system provides more fine tuning of the electricity system, whereas 2,500 megawatts will be a more “foundational” part of the toolkit, said Sparkes.
But what’s currently on the grid is far from the only storage in the province. Many commercial and industrial consumers, such as large manufacturing facilities or downtown office buildings, are using storage to manage their electricity usage, relying on battery energy when prices are high.
The IESO sees that as an opportunity and has changed market rules to allow those customers to sell electricity back to the grid when needed.
As well, the IESO has its eye on the thousands of mobile batteries in electric vehicles, a trend seen in California, that shuttle people around the province every day but sit unused for much of the time.
“If we can enable those batteries to work together in aggregation, or work with other types of technologies like solar or smart building systems in a configuration, like a group of technologies, that becomes a virtual power plant,” Sparkes said.
Peak Power, a company that seeks to “make power plants obsolete,” is running a pilot project with electric vehicles in three downtown Toronto office buildings in which the car batteries can provide electricity to reduce the facility’s overall demand during peak periods using vehicle-to-building charging with bidirectional chargers.
In that model, one vehicle can earn $8,000 per year, said cofounder and chief operating officer Matthew Sachs.
“Battery energy storage will change the energy industry in the same way and for the same reasons that refrigeration changed the milk industry,” he said.
“As you had refrigeration, you could store your commodity and that changed the distribution channels of it. So I believe that energy storage is going to radically change the distribution channels of energy.”
If every home has a solar panel, an electric vehicle and a residential battery, it becomes a generating station, a decentralization that’s not only more environmentally friendly, but also relies less on “monopolized utilities,” Sachs said.
In the next decade, energy demand from electric vehicles is projected to skyrocket, making vehicle-to-grid integration increasingly relevant, and Sachs said the grid can’t grow enough to accommodate a peak demand of hundreds of thousands of vehicles being plugged in to charge at the end of the workday commute. Authorities need to be looking at more incentives such as time-of-use pricing and price signals to ensure the demand is evened out, he said.
“It’s a big risk as much as it’s a big opportunity,” he said. “If we do it wrong, it will cost us billions to fix. If we do it right, it can save us billions.”
Jack Gibbons, the chair of the Ontario Clean Air Alliance, said the provincial and federal governments need to fund and install bidirectional chargers in order to fully take advantage of electric vehicles.
OpenAI Washington Policy Expansion spotlights AI policy, energy infrastructure, data centers, and national security, advocating AI economic zones and a national transmission grid to advance U.S. competitiveness and align with pro-tech administration priorities.
Key Points
OpenAI's D.C. push to scale policy outreach and AI infrastructure across energy, data centers, and national security.
✅ Triples D.C. policy team to expand bipartisan engagement
✅ Advocates AI economic zones and transmission grid build-out
✅ Aligns with pro-tech leadership, prioritizing national security
OpenAI, the creator of ChatGPT, is significantly expanding its presence in Washington, D.C., aiming to influence policy decisions that will shape the future of artificial intelligence (AI) and its integration into critical sectors like energy and national security. This strategic move comes as the company seeks to position itself as a key player in the U.S. economic and security landscape, particularly in the context of global competition with China in strategic industries.
Expansion of Policy Team
To enhance its influence, OpenAI is tripling the size of its Washington policy team. While the 12-person team is still smaller compared to tech giants like Amazon and Meta, it reflects OpenAI's commitment to engaging more actively with policymakers, as debates over Biden's climate law shape the regulatory landscape. The company has recruited individuals from across the political spectrum, including former aides to President Bill Clinton and Vice President Al Gore, to ensure a diverse and comprehensive approach to policy advocacy.
Strategic Initiatives
OpenAI is promoting an ambitious plan to develop tech and energy infrastructure tailored for AI development. This initiative aims to deliver more affordable energy to data centers and reduce corporate electricity bills, which are essential for AI operations. The company is advocating for the establishment of AI economic zones and a national transmission highway to support the growing energy demands of AI technologies. By aligning these proposals with the incoming Trump administration's pro-tech stance, OpenAI seeks to secure federal support for its projects.
Engagement with the Trump Administration
The transition from the Biden administration to the incoming Trump administration presents new opportunities for OpenAI, even as state legal challenges shape early energy policy moves. The Trump administration is perceived as more favorable toward the tech industry, with appointments of Silicon Valley figures like Elon Musk and David Sacks to key positions. OpenAI is leveraging this environment to advocate for policies that support AI development and infrastructure expansion, positioning itself as a strategic asset in the U.S.-China economic and security competition.
The AI industry is increasingly viewed as a critical component of national security and economic competitiveness. OpenAI's efforts to engage with policymakers reflect a broader industry push to be recognized as a vital player in the U.S. economic and security landscape. By promoting AI as a strategic asset, OpenAI aims to secure support for its initiatives, including clean-energy projects in coal communities, and ensure that the U.S. remains at the forefront of AI innovation.
OpenAI's strategic expansion in Washington, D.C., underscores its commitment to influencing policy decisions that will shape the future of AI and its integration into critical sectors. By enhancing its policy team, advocating for infrastructure development, where Alberta's data center boom illustrates rising demand, and aligning with the incoming administration's priorities, even as energy dominance goals face real-world constraints, OpenAI aims to position itself as a key player in the evolving landscape of artificial intelligence. This proactive approach reflects the company's recognition of the importance of policy engagement in driving innovation and securing a competitive edge in the global AI arena.
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.
