Public Service Electric and Gas Company PSE&G is looking to reduce demand by 150 megawatts, and they are hoping Cooper Power Systems can do it for them.
Cooper Power Systems, a division of Cooper Industries plc has entered into an agreement with PSE&G, to provide a demand response solution targeted to provide 150 MW of demand reduction.
PSE&G will upgrade existing load control switches with a retrofit board and begin installing programmable communicating thermostats PCT with a planned implementation of at least 200,000 devices controlling air conditioning A/C units throughout the utilityÂ’s service territory.
“Cooper Power Systems’ demonstrated their commitment to their customers when they fast-tracked a development solution to meet our immediate needs,” said John Veprek, program director at PSE&G. “Following a thorough evaluation of the available technologies and taking into account our experience with different vendors, we were confident in Cooper Power Systems ability to continue to provide industry-leading technologies as we roll out our program.”
The planned implementation is for a four-year roll out and includes a hosted Yukon advanced energy services platform to control the devices using commercial VHF paging networks. The technology in the load control switches and PCTs learns the behavior of the A/C units in order to maximize demand relief during a control event.
“This win represents another significant utility endorsement of our demand response software and our ability to quickly respond to customer needs,” said Tom Pitstick, vice president and general manager of the Energy Automation Solutions division at Cooper Power Systems. “Because Cooper is a trusted Smart Grid provider, PSE&G selected our solution knowing we could quickly begin delivering their 150 MW demand response program with a proven solution and a proven Smart Grid.”
Ireland electricity support measures include PSO levy rebates, RESS 2 renewables, CRU-directed EirGrid backup capacity, and grid investment for the Celtic Interconnector, cutting bills, boosting security of supply, and reducing reliance on imported fossil fuels.
Key Points
Government steps to cut bills and secure supply via PSO rebates, RESS 2 renewables, backup power, and grid upgrades.
✅ PSO levy rebates lower domestic electricity bills.
✅ RESS 2 adds wind, solar, and hydro to the grid.
✅ EirGrid to procure temporary backup capacity for winter peaks.
Ireland's Cabinet has approved a package of measures to help mitigate the rising cost of rising electricity bills, as Irish provider price increases continue to pressure consumers, and to ensure secure supplies to electricity for households and business across Ireland over the coming years.
The package of measures includes changes to the Public Service Obligation (PSO) levy (beyond those announced earlier in the year), which align with emerging EU plans for more fixed-price electricity contracts to improve price stability. The changes will result in rebates, and thus savings, for domestic electricity bills over the course of the next PSO year beginning in October. This further reduction in the PSO levy occurs because of a fall in the relative cost of renewable energy, compared to fossil fuel generation.
The Government has also approved the final results of the second onshore Renewable Electricity Support Scheme (RESS 2) auction, echoing how Ontario's electricity auctions have aimed to lower costs for consumers. This will bring significantly more indigenous wind, solar and hydro-electric energy onto the National Grid. This, in turn, will reduce our reliance on increasingly expensive imported fossil fuels, as the UK explores ending the gas-electricity price link to curb bills.
The package also includes Government approval for the provision of funding for back-up generation capacity, to address risks to security of electricity supply over the coming winters, similar to the UK's forthcoming energy security law approach in this area. The Commission for the Regulation of Utilities (CRU), which has statutory responsibility for security of supply, has directed EirGrid to procure additional temporary emergency generation capacity (for the winters of 2023/2024 to 2025/2026). This will ultimately provide flexible and temporary back-up capacity, to safeguard secure supplies of electricity for households and businesses as we deploy longer-term generation capacity.
Today’s measures also see an increased borrowing limit (€3 billion) for EirGrid – to strengthen our National Grid as part of 'Shaping Our Electricity Future' and to deliver the Celtic (Ireland-France) Interconnector, amid wider European moves to revamp the electricity market that could enhance cross-border resilience. An increased borrowing limit (€650 million) for Bord na Móna will drive greater deployment of indigenous renewable energy across the Midlands and beyond – as part of its 'Brown to Green' strategy, while measures like the UK's household energy price cap illustrate the scale of consumer support elsewhere.
Cabin Creek Solar Project Montana delivers 150 MW of utility-scale solar under a Power Purchase Agreement, with Basin Electric and Clenera supplying renewable energy, enhancing grid reliability, and reducing carbon emissions for 30,000 homes.
Key Points
A 150 MW solar PPA near Baker by Basin Electric and Clenera, delivering reliable renewable power and carbon reduction.
✅ 150 MW across two 75 MW sites near Baker, Montana
A new solar project in Montana will provide another 150 megawatts (MW) of affordable, renewable power to Basin Electric customers and co-op members across the region.
Basin Electric Power Cooperative (Basin Electric) and Clenera Renewable Energy, announced today the execution of a Power Purchase Agreement (PPA) for the Cabin Creek Solar Project. Cabin Creek is Basin Electric's second solar PPA, and the result of the cooperative's continuing goal of providing a diverse mix of energy sources that are cost-effective for its members.
When completed, Cabin Creek will consist of two, 75-MW projects in southeastern Montana, five miles west of Baker. According to Clenera, the project will eliminate 265,000 tons of carbon dioxide per year and power 30,000 homes, while communities such as the Ermineskin First Nation advance their own generation efforts.
"Renewable technology has advanced dramatically in recent years, with rapid growth in Alberta underscoring broader trends, which means even more affordable power for Basin Electric's customers," said Paul Sukut, CEO and general manager of Basin Electric. "Basin Electric is excited to purchase the output from this project to help serve our members' growing energy needs. Adding solar further promotes our all-of-the-above energy solution as we generate energy using a diverse resource portfolio including coal, natural gas, and other renewable resources to provide reliable, affordable, and environmentally safe generation.
"Clenera is proud to partner with Basin Electric Power Cooperative to support the construction of the Cabin Creek Solar projects in Montana," said Jared McKee, Clenera's director of Business Development. "We truly believe that Basin Electric will be a valuable partner as we aim to deliver today's new era of reliable, battery storage increasingly enabling round-the-clock service, affordable, and clean energy."
"We're pleased that Southeast Electric will be home to the Cabin Creek Solar Project," said Jack Hamblin, manager of Southeast Electric Cooperative, a Basin Electric Class C member headquartered in Ekalaka, Montana. "This project is one more example of cooperatives working together to use economies of scale to add affordable generation for all their members - similar to what was done 70 years ago when cooperatives were first built."
Basin Electric Class A member Upper Missouri Power Cooperative, headquartered in Sidney, Montana, provides wholesale power to Southeast Electric and 10 other distribution cooperatives in western North Dakota and eastern Montana. "It is encouraging to witness the development of cost-competitive energy, including projects in Alberta contracted at lower cost than natural gas that demonstrate market shifts, like the Cabin Creek Solar Project, which will be part of the energy mix we purchase from Basin Electric for our member systems, said Claire Vigesaa, Upper Missouri's general manager. "The energy needs in our region are growing and this project will help us serve both our members, and our communities as a whole."
Cabin Creek will bring significant economic benefits to the local area. According to Clenera, the project will contribute $8 million in property taxes to Fallon County and $5 million for the state of Montana over 35 years. They say it will also create approximately 300 construction jobs and two to three full-time jobs.
"This project underscores the efforts by Montana's electric cooperatives to continue to embrace more carbon-free technology," said Gary Wiens, CEO of Montana Electric Cooperatives' Association. "It also demonstrates Basin Electric's commitment to seek development of renewable energy projects in our state. It's exciting that these two projects combined are 50 times larger than our current largest solar array in Montana."
Cabin Creek is anticipated to begin operations in late 2023.
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.
Yukon Renewable Energy Funding backs wind turbines, grid-scale battery storage, and transmission line upgrades, cutting diesel dependence, lowering greenhouse gas emissions, and strengthening Yukon Energy's isolated grid for remote communities, local jobs, and future growth.
Key Points
Federal support for Yukon projects adding wind, battery storage, and grid upgrades to cut diesel use and emissions.
✅ Three 100 kW wind turbines will power Destruction Bay.
✅ 8 MW battery storage smooths peaks and reduces diesel.
✅ Mayo-McQuesten 138 kV line upgrade boosts reliability.
Kluane First Nation in Yukon will receive a total of $3.1 million in funding from the federal government to install and operate wind turbines that will help reduce the community’s diesel reliance.
According to a release, the community will integrate three 100-kilowatt turbines in Destruction Bay, Yukon, providing a renewable energy source for their local power grid that will reduce greenhouse gas emissions and create local jobs in the community.
A $2-million investment from Natural Resources Canada came from the Clean Energy for Rural and Remote Communities Program, part of the Government of Canada’s Investing in Canada infrastructure plan, which supports green energy solutions across jurisdictions. Crown-Indigenous Relations’ and Northern Affairs Canada also contributed a $1.1-million investment from the Northern REACHE Program.
Also, the Government of Canada announced more than $39.2 million in funding for two Yukon Energy projects that will increase the reliability of Yukon’s electrical grid, including exploration of a potential connection to the B.C. grid to bolster resiliency, and help build the robust energy system needed to support future growth. The investment comes from the government’s Green Infrastructure Stream (GIS) of the Investing in Canada infrastructure plan.
Project 1: Grid-scale battery storage
The federal government is investing $16.5 million in Yukon Energy’s construction of a new battery storage system in Yukon. Once completed, the 8 MW battery will be the largest grid-connected battery in the North, and one of the largest in Canada, alongside major Ontario battery projects underway.
The new battery is a critical investment in Yukon Energy’s ability to meet growing demands for power and securing Yukon’s energy future. As an isolated grid, one of the largest challenges Yukon Energy faces is meeting peak demands for power during winter months, as electrification grows with EV adoption in the N.W.T. and beyond.
When complete, the new system will store excess electricity generated during off-peak periods, complementing emerging vehicle-to-grid integration approaches, and provide Yukoners with access to more power during peak periods. This new energy storage system will create a more reliable power supply and help reduce the territory’s reliance on diesel fuel. Over the 20-year life of project, the new battery is expected to reduce carbon emissions in Yukon by more than 20,000 tonnes.
A location for the new battery energy storage system has not been identified. Yukon Energy will begin permitting of the project in 2020 with construction targeted to be complete by mid-2023.
Project 2: Replacing and upgrading the Mayo to McQuesten Transmission Line
Yukon Energy has received $22.7 million in federal funding to proceed with Stage 1 of the Stewart to Keno City Transmission Project – replacing and upgrading the 65 year-old transmission line between Mayo and McQuesten. The project also includes the addition of system protection equipment at the Stewart Crossing South substation. The Yukon government, through the Yukon Development Corporation, has already provided $3.5 million towards planning for the project.
Replacing the Mayo to McQuesten transmission line is critical to Yukon Energy’s ability to deliver safe and reliable electricity to customers in the Mayo and Keno regions, mirroring broader regional transmission initiatives that enhance grid resilience, and to support economic growth in Yukon. The transmission line has reached end-of-life and become increasingly unreliable for customers in the area.
The First Nation of Na-Cho Nyak Dun has expressed their support of this project. The project has also been approved by the Yukon Environmental and Socio-Economic Assessment Board.
Yukon Energy will begin replacing and upgrading the 31 km transmission line between Mayo and McQuesten in 2020. Construction is expected to be complete in late 2020. When finished, the new 138 kV transmission line will provide more reliable electricity to customers in the Mayo and Keno regions and be equipped to support industrial growth and development in the area, including the Victoria Gold Mine, with renewable power from the Yukon grid.
Planning work for the remainder of the Stewart to Keno City Transmission Project has been completed. Yukon Energy continues to explore funding opportunities that are needed to proceed with other stages of the project.
Nithi Mountain Wind Project delivers 200 MW of renewable wind power in British Columbia under a BC Hydro electricity purchase deal, producing 600 GWh yearly, led by Stellat'en First Nation and Innergex.
Key Points
A 200 MW wind farm in British Columbia producing 600 GWh yearly, co-owned by Stellat'en First Nation and Innergex.
✅ 30-year BC Hydro take-or-pay PPA, CPI-indexed
✅ 200 MW capacity, ~600 GWh per year for ~60,000 homes
✅ 51% Stellat'en First Nation; operations targeted for 2030
In December 2024, a significant development unfolded in British Columbia's renewable energy sector, where the clean-energy regulatory process continues to evolve, as Stellat'en First Nation and Innergex Renewable Energy Inc. announced the signing of a 30-year electricity purchase agreement with BC Hydro. This agreement pertains to the Nithi Mountain Wind Project, a 200 MW initiative poised to enhance the province's clean energy capacity.
Project Overview
The Nithi Mountain Wind Project is a collaborative venture between Stellat'en First Nation, which holds a 51% stake, and Innergex Renewable Energy Inc., which holds a 49% stake. Located in the Bulkley-Nechako region of British Columbia, the project is expected to generate approximately 600 GWh of renewable electricity annually, comparable to other large-scale projects like the 280 MW wind farm in Alberta now online, sufficient to power around 60,000 homes. The wind farm is scheduled to commence commercial operations in 2030.
Economic and Community Impact
This partnership is anticipated to create approximately 150 job opportunities during the development, construction, and operational phases, thereby supporting local economic growth and workforce development, and aligns with recent federal green electricity procurement efforts that signal broader market support. The long-term electricity purchase agreement with BC Hydro is structured as a 30-year take-or-pay contract, indexed to a predefined percentage of the Consumer Price Index (CPI), ensuring financial stability and protection against inflation.
Environmental and Cultural Considerations
The Nithi Mountain Wind Project is being developed in close collaboration with First Nations in the area, guided by collaborative land-use planning. The project integrates cultural preservation, environmental stewardship, and economic empowerment for Indigenous communities in the Bulkley-Nechako region, while other solutions such as tidal energy for remote communities are also advancing across Canada. The project is committed to minimizing environmental impact by avoiding sensitive cultural and ecological resources and integrating sustainability at every stage, with remediation practices to restore the land, preserve cultural values, and enhance biodiversity and wildlife habitats if decommissioned.
Broader Implications
This agreement underscores a growing trend of collaboration between Indigenous communities, exemplified by the Ermineskin First Nation project emerging nationwide, and renewable energy developers in Canada. Such partnerships are instrumental in advancing sustainable energy projects that respect Indigenous rights and contribute to the nation's clean energy objectives, as renewable power developers find that diversified energy sources strengthen project outcomes. The Nithi Mountain Wind Project exemplifies how integrating traditional knowledge with modern renewable energy technologies can lead to mutually beneficial outcomes for both Indigenous communities and the broader society.
In summary, the Nithi Mountain Wind Project represents a significant step forward in British Columbia's renewable energy landscape, highlighting the importance of collaboration between Indigenous communities and renewable energy developers. The project promises substantial economic, environmental, and cultural benefits, setting a precedent for future partnerships in the clean energy sector, as large-scale storage acquisitions like Centrica's battery project illustrate complementary pathways to unlock wind potential.
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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