International Business Machines Corp. said it reached a deal to provide high-speed Internet service to rural areas using existing power lines.
IBM's $9.6 million deal with International Broadband Electric Communications will deploy IBEC's Broadband over Power Lines equipment to customers of electrical cooperatives, InformationWeek reported.
"Americans in rural areas of the country trail their urban and suburban counterparts in broadband availability," IBEC Chief Executive Officer Scott Lee said in a statement.
"This capability will play a crucial role in rural health, education and economic development, while closing the digital divide that exists between well served and under served America," Lee said.
IBM said there were more than 900 electrical cooperatives in the country that make up 45 percent of the nation's power grid.
Customers need only to plug in their computers to any electrical outlet with Broadband over Power Line service to receive a high-speed broad band service.
But the system has drawbacks with some complaining it interferes with short wave radio signals, InformationWeek reported.
Saamis Solar Park advances Medicine Hat's renewable energy strategy, as DP Energy secures AUC approval for North America's largest urban solar, repurposing contaminated land; capacity phased from 325 MW toward an initial 75 MW.
Key Points
A 325 MW solar project in Medicine Hat, Alberta, repurposing contaminated land; phased to 75 MW under city ownership.
✅ City acquisition scales capacity to 75 MW in phased build
✅ AUC approval enables construction and grid integration
✅ Reuses phosphogypsum-impacted land near fertilizer plant
DP Energy, an Irish renewable energy developer, has finalized the sale of the Saamis Solar Park—a 325 megawatt (MW) solar project—to the City of Medicine Hat in Alberta, Canada. This transaction marks the development of North America's largest urban solar initiative, while mirroring other Canadian clean-energy deals such as Canadian Solar project sales that signal market depth.
Project Development and Approval
DP Energy secured development rights for the Saamis Solar Park in 2017 and obtained a development permit in 2021. In 2024, the Alberta Utilities Commission (AUC) granted approval for construction and operation, reflecting Alberta's solar growth trends in recent years, paving the way for the project's advancement.
Strategic Acquisition by Medicine Hat
The City of Medicine Hat's acquisition of the Saamis Solar Park aligns with its commitment to enhancing renewable energy infrastructure. Initially, the project was slated for a 325 MW capacity, which would significantly bolster the city's energy supply. However, the city has proposed scaling the project to a 75 MW capacity, focusing on a phased development approach, and doing so amid challenges with solar expansion in Alberta that influence siting and timing. This adjustment aims to align the project's scale with the city's current energy needs and strategic objectives.
Utilization of Contaminated Land
An innovative aspect of the Saamis Solar Park is its location on a 1,600-acre site previously affected by industrial activity. The land, near Medicine Hat's fertilizer plant, was previously compromised by phosphogypsum—a byproduct of fertilizer production. DP Energy's decision to develop the solar park on this site exemplifies a productive reuse of contaminated land, transforming it into a source of clean energy.
Benefits to Medicine Hat
The development of the Saamis Solar Park is poised to deliver multiple benefits to Medicine Hat:
Energy Supply Enhancement: The project will augment the city's energy grid, much like municipal solar projects that provide local power, providing a substantial portion of its electricity needs.
Economic Advantages: The city anticipates financial savings by reducing carbon tax liabilities, as lower-cost solar contracts have shown competitiveness, through the generation of renewable energy.
Environmental Impact: By investing in renewable energy, Medicine Hat aims to reduce its carbon footprint and contribute to global sustainability efforts.
DP Energy's Ongoing Commitment
Despite the sale, DP Energy maintains a strong presence in Canada, where Indigenous-led generation is expanding, with a diverse portfolio of renewable energy projects, including solar, onshore wind, storage, and offshore wind initiatives. The company continues to focus on sustainable development practices, striving to minimize environmental impact while maximizing energy production efficiency.
The transfer of the Saamis Solar Park to the City of Medicine Hat represents a significant milestone in renewable energy development. It showcases effective land reutilization, strategic urban planning, and a shared commitment to sustainable energy solutions, aligning with federal green electricity procurement that reinforces market demand. This project not only enhances the city's energy infrastructure but also sets a precedent for integrating large-scale renewable energy projects within urban environments.
Hourly Electricity Emissions Tracking maps grid balancing areas, embodied emissions, and imports/exports, revealing carbon intensity shifts across PJM, ERCOT, and California ISO, and clarifying renewable energy versus coal impacts on health and climate.
Key Points
An hourly method tracing generation, flows, and embodied emissions to quantify carbon intensity across US balancing areas.
✅ Hourly traces of imports/exports and generation mix
✅ Consumption-based carbon intensity by balancing area
✅ Policy insights for renewables, coal, health costs
In the United States, electricity generation accounts for nearly 30% of our carbon emissions. Some states have responded to that by setting aggressive renewable energy standards; others are hoping to see coal propped up even as its economics get worse. Complicating matters further is the fact that many regional grids are integrated, and as America goes electric the stakes grow, meaning power generated in one location may be exported and used in a different state entirely.
Tracking these electricity exports is critical for understanding how to lower our national carbon emissions. In addition, power from a dirty source like coal has health and environment impacts where it's produced, and the costs of these aren't always paid by the parties using the electricity. Unfortunately, getting reliable figures on how electricity is produced and where it's used is challenging, even for consumers trying to find where their electricity comes from in the first place, leaving some of the best estimates with a time resolution of only a month.
Now, three Stanford researchers—Jacques A. de Chalendar, John Taggart, and Sally M. Benson—have greatly improved on that standard, and they have managed to track power generation and use on an hourly basis. The researchers found that, of the 66 grid balancing areas within the United States, only three have carbon emissions equivalent to our national average, and they have found that imports and exports of electricity have both seasonal and daily changes. de Chalendar et al. discovered that the net results can be substantial, with imported electricity increasing California's emissions/power by 20%.
Hour by hour To figure out the US energy trading landscape, the researchers obtained 2016 data for grid features called balancing areas. The continental US has 66 of these, providing much better spatial resolution on the data than the larger grid subdivisions. This doesn't cover everything—several balancing areas in Canada and Mexico are tied in to the US grid—and some of these balancing areas are much larger than others. The PJM grid, serving Pennsylvania, New Jersey, and Maryland, for example, is more than twice as large as Texas' ERCOT, in a state that produces and consumes the most electricity in the US.
Despite these limitations, it's possible to get hourly figures on how much electricity was generated, what was used to produce it, and whether it was used locally or exported to another balancing area. Information on the generating sources allowed the researchers to attach an emissions figure to each unit of electricity produced. Coal, for example, produces double the emissions of natural gas, which in turn produces more than an order of magnitude more carbon dioxide than the manufacturing of solar, wind, or hydro facilities. These figures were turned into what the authors call "embodied emissions" that can be traced to where they're eventually used.
Similar figures were also generated for sulfur dioxide and nitrogen oxides. Released by the burning of fossil fuels, these can both influence the global climate and produce local health problems.
Huge variation The results were striking. "The consumption-based carbon intensity of electricity varies by almost an order of magnitude across the different regions in the US electricity system," the authors conclude. The low is the Bonneville Power grid region, which is largely supplied by hydropower; it has typical emissions below 100kg of carbon dioxide per megawatt-hour. The highest emissions come in the Ohio Valley Electric region, where emissions clear 900kg/MW-hr. Only three regional grids match the overall grid emissions intensity, although that includes the very large PJM (where capacity auction payouts recently fell), ERCOT, and Southern Co balancing areas.
Most of the low-emissions power that's exported comes from the Pacific Northwest's abundant hydropower, while the Rocky Mountains area exports electricity with the highest associated emissions. That leads to some striking asymmetries. Local generation in the hydro-rich Idaho Power Company has embodied emissions of only 71kg/MW-hr, while its imports, coming primarily from Rocky Mountain states, have a carbon content of 625kg/MW-hr.
The reliance on hydropower also makes the asymmetry seasonal. Local generation is highest in the spring as snow melts, but imports become a larger source outside this time of year. As solar and wind can also have pronounced seasonal shifts, similar changes will likely be seen as these become larger contributors to many of these regional grids. Similar things occur daily, as both demand and solar production (and, to a lesser extent, wind) have distinct daily profiles.
The Golden State California's CISO provides another instructive case. Imports represent less than 30% of its total electric use in 2016, yet California electricity imports provided 40% of its embodied emissions. Some of these, however, come internally from California, provided by the Los Angeles Department of Water and Power. The state itself, however, has only had limited tracking of imported emissions, lumping many of its sources as "other," and has been exporting its energy policies to Western states in ways that shape regional markets.
Overall, the 2016 inventory provides a narrow picture of the US grid, as plenty of trends are rapidly changing our country's emissions profile, including the rise of renewables and the widespread adoption of efficiency measures and other utility trends in 2017 that continue to evolve. The method developed here can, however, allow for annual updates, providing us with a much better picture of trends. That could be quite valuable to track things like how the rapid rise in solar power is altering the daily production of clean power.
More significantly, it provides a basis for more informed policymaking. States that wish to promote low-emissions power can use the information here to either alter the source of their imports or to encourage the sites where they're produced to adopt more renewable power. And those states that are exporting electricity produced primarily through fossil fuels could ensure that the locations where the power is used pay a price that includes the health costs of its production.
Ukraine Power Grid Attacks disrupt critical infrastructure as missiles and drones strike power plants, substations, and lines, causing blackouts. Emergency repairs, international aid, generators, and renewables bolster resilience and keep hospitals and water running.
Key Points
Russian strikes on Ukraine's power infrastructure cause blackouts; repairs and aid sustain hospitals and water.
✅ Missile and drone strikes target plants, substations, and lines.
✅ Crews restore power under fire; air defenses protect sites.
✅ Allies supply equipment, generators, and grid repair expertise.
Ukraine is facing an ongoing battle to maintain its electrical grid in the wake of relentless Russian attacks targeting power plants and energy infrastructure. These attacks, which have intensified in the last year, are part of Russia's broader strategy to weaken Ukraine's ability to function amid the ongoing war. Power plants, substations, and energy lines have become prime targets, with Russian forces using missiles and drones to destroy critical infrastructure, as western Ukraine power outages have shown, leaving millions of Ukrainians without electricity and heating during harsh winters.
The Ukrainian government and energy companies are working tirelessly to repair the damage and prevent total blackouts, while also trying to ensure that civilians have access to vital services like hospitals and water supplies. Ukraine has received support from international allies in the form of technical assistance and equipment to help strengthen its power grid, and electricity reserve updates suggest outages can be avoided if no new strikes occur. However, the ongoing nature of the attacks and the complexity of repairing such extensive damage make the situation extraordinarily difficult.
Despite these challenges, Ukraine's resilience is evident, even as winter pressures on the battlefront intensify operations. Energy workers are often working under dangerous conditions, risking their lives to restore power and prevent further devastation. The Ukrainian government has prioritized the protection of energy infrastructure, with military forces being deployed to safeguard workers and critical assets.
Meanwhile, the international community continues to support Ukraine through financial and technical aid, though some U.S. support programs have ended recently, as well as providing temporary power solutions, like generators, to keep essential services running. Some countries have even sent specialized equipment to help repair damaged power lines and energy plants more quickly.
The humanitarian consequences of these attacks are severe, as access to electricity means more than just light—it's crucial for heating, cooking, and powering medical equipment. With winter temperatures often dropping below freezing, plans to keep the lights on are vital to protect vulnerable communities, and the lack of reliable energy has put many lives at risk.
In response to the ongoing crisis, Ukraine has also focused on enhancing its energy independence, seeking alternatives to Russian-supplied energy. This includes exploring renewable energy sources, such as solar and wind power, and new energy solutions adopted by communities to overcome winter blackouts, which could help reduce reliance on traditional energy grids and provide more resilient options in the future.
The battle for energy infrastructure in Ukraine illustrates the broader struggle of the country to maintain its sovereignty and independence in the face of external aggression. The destruction of power plants is not only a military tactic but also a psychological one—meant to instill fear and disrupt daily life. However, the unwavering spirit of the Ukrainian people, alongside international support, including Ukraine's aid to Spain during blackouts as one example, continues to ensure that the fight to "keep the lights on" is far from over.
As Ukraine works tirelessly to repair its energy grid, it also faces the challenge of preparing for the long-term impact of these attacks. The ongoing war has highlighted the importance of securing energy infrastructure in modern conflicts, and the world is watching as Ukraine's resilience in this area could serve as a model for other nations facing similar threats.
Ukraine’s energy struggle is far from over, but its determination to keep the lights on remains a beacon of hope and defiance in the face of ongoing adversity.
Canada Clean Electricity Regulations align climate policy with grid reliability, scaling renewables, energy storage, and low-carbon power to reach net-zero by 2050 while maintaining affordability through federal incentives, provincial flexibility, and investment.
Key Points
Nationwide rules to decarbonize power by 2050, capping emissions and protecting grid reliability and affordability.
✅ Net-zero electricity by 2050 with strict emissions limits
✅ Provincial flexibility and federal investments to cut costs
✅ Scales renewables, storage, and clean firm power for reliability
Canada's final Clean Electricity Regulations, unveiled in December 2024, alongside complementary provincial frameworks such as Ontario's clean electricity regulations that guide provincial implementation, represent a critical step toward ensuring a sustainable and reliable energy future. With electricity demand set to rise as the country’s population and economy grow, the Canadian government has put forward a robust plan that balances climate goals with the need for reliable, affordable power.
The regulations are designed to reduce greenhouse gas emissions from the electricity sector, which is already one of Canada's cleanest, with 85% of its electricity sourced from renewable energies like hydro, wind, and solar, and growing attention to clean grids and batteries nationwide. The target is to achieve net-zero emissions in electricity generation by 2050, a goal that will support the country’s broader climate ambitions.
One of the central goals of the Clean Electricity Regulations is to make sure that Canada’s power grid can accommodate future demand in light of a critical electrical supply crunch identified by analysts, while ensuring that emissions are cut effectively. The regulations set strict pollution limits but allow flexibility for provinces and territories to meet these goals in ways that suit their local circumstances. This approach recognizes the diverse energy resources across Canada, from the large-scale hydroelectric capacity in Quebec to the growing wind and solar projects in the West.
A key benefit of these regulations is the assurance that they will not result in higher electricity rates for most Canadians. In fact, according to government analyses, and resources like the online CER bill tool that explain how fees and usage affect charges, the regulations are expected to have a neutral or even slightly positive impact on electricity costs. This is due in part to significant federal investments in the electricity sector, totaling over $60 billion. These investments are intended to support the transition to clean electricity while minimizing costs for consumers.
The shift to clean electricity is also expected to generate significant savings for Canadian households. As energy prices continue to fluctuate, clean electricity, especially from renewable sources, is becoming more cost-competitive compared to fossil fuels. Over the next decade, this transition is expected to result in $15 billion in total savings for Canadians, with 84% of households projected to benefit from lower energy bills. The savings are a result of federal incentives aimed at encouraging the adoption of efficient electric appliances, vehicles, and heating systems.
Moreover, reducing emissions from the electricity sector will play a major role in cutting Canada’s overall greenhouse gas pollution. By 2050, it’s estimated that these regulations will reduce nearly 181 megatonnes of emissions, which is equivalent to removing over 55 million cars from the road. This is a crucial step in meeting Canada’s climate targets and mitigating the impacts of climate change, such as extreme weather events, which have already led to significant economic losses.
The economic benefits extend beyond savings on energy bills. The regulations and the broader clean electricity strategy will create substantial job opportunities. The clean energy sector, which includes jobs in wind, solar, and nuclear power, is poised for massive growth, and provinces like Alberta have outlined a path to clean electricity to support that momentum. It’s estimated that by 2030, the transition to clean electricity could create 400,000 new jobs, with further job growth projected for the years to come. These jobs are expected to include roles in both the construction and operation of new energy infrastructure, many of which will be unionized positions offering good wages and benefits.
To help meet the rising demand for clean energy, the government’s strategy emphasizes technological innovation and the integration of new energy sources, including market design updates such as proposed market changes that can enable investment. Renewable energy technologies such as wind and solar power have become increasingly cost-competitive, and their continued development is expected to reduce the overall cost of electricity generation. The regulations also encourage the adoption of energy storage solutions, which are essential for managing the intermittent nature of renewable energy sources.
In addition to the environmental and economic benefits, the Clean Electricity Regulations will help improve public health. Air pollution from fossil fuel power generation is a major contributor to respiratory illnesses and other health issues. By transitioning to clean energy sources, Canada can reduce harmful air pollutants, leading to better health outcomes and a lower burden on the healthcare system.
As Canada moves toward a net-zero electricity grid, including the federal 2035 target that some have criticized as changing goalposts in Saskatchewan, the Clean Electricity Regulations represent a comprehensive and flexible approach to managing the energy transition. With significant investments in clean energy technologies and the adoption of policies that ensure affordable electricity for all Canadians, the government is setting the stage for a cleaner, more sustainable future. These efforts will not only help Canada meet its climate goals but also create a thriving clean energy economy that benefits workers, businesses, and families across the country.
BC Hydro Rate Freeze delivers immediate relief on electricity rates in British Columbia, reversing a planned 3% hike, as BCUC oversight, a utility review, and Site C project debates shape provincial energy policy.
Key Points
A one-year provincial policy halting BC Hydro electricity rate hikes while a utility review finds cost savings.
✅ Freeze replaces planned 3% hike approved by BCUC.
✅ Government to conduct comprehensive BC Hydro review.
✅ Critics warn $150M revenue loss impacts capital projects.
British Columbia's NDP government has announced it will freeze BC Hydro rates effective immediately, fulfilling a key election promise.
Energy, Mines and Petroleum Resources Minister Michelle Mungall says hydro rates have gone up by more than 24 per cent in the last four years and by more than 70 per cent since 2001, reflecting proposals such as a 3.75% increase over two years announced previously.
"After years of escalating electricity costs, British Columbians deserve a break on their bills," Mungall said in a news release.
BC Hydro had been approved by the B.C. Utilities Commission to increase the rate by three per cent next year, but Mungall said it will pull back its request in order to comply with the freeze.
In the meantime, the government says it will undertake a comprehensive review of the utility meant to identify cost-savings measures for customers often asked to pay an extra $2 a month on electricity bills.
The Liberal critic, Tracy Redies, says the one year rate freeze is going to cost BC Hydro, calling it a distraction from the bigger issue of the future of the Site C project and the oversight of a BC Hydro fund surplus as well.
"A one year rate freeze costs Hydro $150 million," Redies said. "That means there's $150 million less to invest in capital projects and other investments that the utility needs to make."
"This is putting off decisions that should be made today to the future."
Recommendations from the review — including possible new rates — will be implemented starting in April 2019.
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.
