An application to build a $2 billion power line from West Virginia to Maryland should be dismissed because less expensive alternatives should be considered first, say staff reviewing the project for the West Virginia Public Service Commission.
Developers of the Potomac-Appalachian Transmission Highline, or PATH, say the 765-kilovolt line is needed to meet projected power demand along the East Coast by 2015.
But PSC staff said it was “ludicrous” to continue with the project while changes to the region’s existing power grid are being contemplated. Staff specifically mentioned Virginia-based Dominion’s recent notice to rebuild its 500-kilovolt line from Mt. Storm in West Virginia to the Doubs substation in Maryland. That upgrade and other improvements are estimated to cost $500 million to $600 million.
Another planned project is the Mid-Atlantic Power Pathway in Maryland. The line is to provide power to the Delmarva Peninsula.
Dominion says the Mt. Storm-Doubs line, which was built in 1966, must be rebuilt to maintain service. Developers gave the lineÂ’s current condition as a justification for the PATH project and the separate Trans-Allegheny Interstate Line.
“The rebuild will be a more stable line with 65 percent increased capacity,” PSC staff said it its December 10 filing. The additional capacity “will push the need for the PATH line further out on the horizon,” perhaps to 2020, staff wrote.
PATH is a joint venture of Allegheny Energy Co. and American Electric Power Co. The proposed 275-mile line would run from AEPÂ’s John Amos plant in West Virginia, across three counties in Northern Virginia, to a substation near Kemptown in Frederick County.
At least 250 groups, representing landowners, The Sierra Club, local county commissions and boards of education are opposed to PATHÂ’s construction. Many of them have submitted letters supporting the latest staff filing.
The filing marks the second time PSC staff has recommended the application be dismissed. In October 2009, staff sought to dismiss the application because MarylandÂ’s utility commission had dismissed an application in that state, saying it had been improperly filed.
Instead, the utilities agreed to extend the deadline for when the PSC must make a decision from May 16 to July 28, 2011.
PATH spokeswoman Jeri Matheny said the Dominion line “ties in very well” with the PATH project. Also, once PATH is built the Dominion line can be taken out of service for a rebuild, he said.
Matheny did not have an immediate comment on the staffÂ’s recommendation to dismiss the application, saying a formal response would be filed with the PSC.
Earlier this month PJM Interconnection approved the Mt. Storm-Doubs line, but also reaffirmed its support of the PATH project. PJM manages the electrical grid in a 13-state region.
If the three-member PSC doesnÂ’t dismiss the PATH application, staff is asking that it require developers to submit new testimony regarding the economic and environmental aspects of the project. Staff is also asking that AEP and Allegheny Energy again agree to extend the decision deadline.
Natrium small modular reactor pairs a sodium-cooled fast reactor with molten salt storage to deliver load-following, dispatchable nuclear power, enhancing grid flexibility and peaking capacity as TerraPower and GE Hitachi pursue factory-built, affordable deployment.
Key Points
A TerraPower-GE Hitachi SMR joining a sodium-cooled reactor with molten salt storage for flexible, dispatchable power.
✅ 345 MW base; 500 MW for 5.5 hours via thermal storage
✅ Sodium-cooled coolant and molten salt storage enable load-following
✅ Backed by major utilities; factory-built modules aim lower costs
Nuclear power is the Immovable Object of generation sources. It can take days just to bring a nuclear plant completely online, rendering it useless as a tool to manage the fluctuations in the supply and demand on a modern energy grid.
Now a firm launched by Bill Gates in 2006, TerraPower, in partnership with GE Hitachi Nuclear Energy, believes it has found a way to make the infamously unwieldy energy source a great deal nimbler, drawing on next-gen nuclear ideas — and for an affordable price.
The new design, announced by TerraPower on August 27th, is a combination of a "sodium-cooled fast reactor" — a type of small reactor in which liquid sodium is used as a coolant — and an energy storage system. While the reactor could pump out 345 megawatts of electrical power indefinitely, the attached storage system would retain heat in the form of molten salt and could discharge the heat when needed, increasing the plant’s overall power output to 500 megawatts for more than 5.5 hours.
“This allows for a nuclear design that follows daily electric load changes and helps customers capitalize on peaking opportunities driven by renewable energy fluctuations,” TerraPower said.
Dubbed Natrium after the Latin name for sodium ('natrium'), the new design will be available in the late 2020s, said Chris Levesque, TerraPower's president and CEO.
TerraPower said it has the support of a handful of top U.S. utilities, including Berkshire Hathaway Energy subsidiary Pacificorp, Energy Northwest, and Duke Energy.
The reactor's molten salt storage add-on would essentially reprise the role currently played by coal- or gas-fired power stations or grid-scale batteries: each is a dispatchable form of power generation that can quickly ratchet up or down in response to changes in grid demand or supply. As the power demands of modern grids become ever more variable with additions of wind and solar power — which only provide energy when the wind is blowing or the sun shining — low-carbon sources of dispatchable power are needed more and more, and Europe is losing nuclear power at a difficult moment for energy security. California’s rolling blackouts are one example of what can happen when not enough power is available to be dispatched to meet peak demand.
The use of molten salt, which retains heat at extremely high temperatures, as a storage technology is not new. Concentrated solar power plants also collect energy in the form of molten salt, although such plants have largely been abandoned in the U.S. The technology could enjoy new life alongside nuclear plants: TerraPower and GE Hitachi Nuclear are only two of several private firms working to develop reactor designs that incorporate molten salt storage units, including U.K.- and Canada-based developer Moltex Energy.
The Gates-backed venture and its partner touted the "significant cost savings" that would be achieved by building major portions of their Natrium plants through not a custom but an industrial process — a defining feature of the newest generation of advanced reactors is that their parts can be made in factories and assembled on-site — although more details on cost weren't available. Reuters reported earlier that each plant would cost around $1 billion.
NuScale Power
A day after TerraPower and GE Hitachi's unveiled their new design, another nuclear firm — Portland, Oregon-based NuScale Power — announced that the U.S. Nuclear Regulatory Commission (NRC) had completed its final safety evaluation of NuScale’s new small modular reactor design.
It was the first small modular reactor design ever to receive design approval from the NRC, NuScale said.
The approval means customers can now pursue plans to develop its reactor design confident that the NRC has signed off on its safety aspects. NuScale said it has signed agreements with interested parties in the U.S., Canada, Romania, the Czech Republic, and Jordan, and is in the process of negotiating more.
NuScale previously said that construction on one of its plants could begin in Utah in 2023, with the aim of completing the first Power Module in 2026 and the remaining 11 modules in 2027.
NuScale An artist’s rendering of NuScale Power’s small modular nuclear reactor plant. NUSCALE POWER NuScale’s reactor is smaller than TerraPower’s. Entirely factory-built, each of its Power Modules would generate 60 megawatts of power. The design, typical of advanced reactors, uses pressurized water reactor technology, with one power plant able to house up to 12 individual Power Modules.
In a sign of the huge amounts of time and resources it takes to get new nuclear technology to the market’s doorstep, NuScale said it first completed its Design Certification Application in December 2016. NRC officials then spent as many as 115,000 hours reviewing it, NuScale said, in what was only the first of several phases in the review process.
In January 2019, President Donald Trump signed into law the Nuclear Energy Innovation and Modernization Act (NEIMA), designed to speed the licensing process for advanced nuclear reactors, and the DOE under Secretary Rick Perry moved to advance nuclear development through parallel initiatives. The law had widespread bipartisan support, underscoring Democrats' recent tentative embrace of nuclear power.
An industry eager to turn the page
After a boom in the construction of massive nuclear power plants in the 1960s and 70s, the world's aging fleet of nuclear plants suffers from rising costs and flagging public support. Nuclear advocates have for years heralded so-called small modular reactors or SMRs as the cheaper and more agile successors to the first generation of plants, and policy moves such as the UK's green industrial revolution lay out pathways for successive waves of reactors. But so far a breakthrough on cost has proved elusive, and delays in development timelines have been abundant.
Edwin Lyman, the director of nuclear power safety at the Union of Concerned Scientists, suggested on Twitter that the nuclear designs used by TerraPower and GE Hitachi had fallen short of a major innovation. “Oh brother. The last thing the world needs is a fleet of sodium-cooled fast reactors,” he wrote.
Still, climate scientists view nuclear energy as a crucial source of zero-carbon energy, with analyses arguing that net-zero emissions may be impossible without nuclear in many scenarios, if the world stands a chance at limiting global temperature increases to well below 2 degrees Celsius above pre-industrial levels. Nearly all mainstream projections of the world’s path to keeping the temperature increase below those levels feature nuclear energy in a prominent role, including those by the United Nations and the International Energy Agency (IEA).
According to the IEA: “Achieving the clean energy transition with less nuclear power is possible but would require an extraordinary effort.”
Atlantic Canada Hurricane Resilience focuses on climate change adaptation: grid hardening, burying lines, coastline resiliency to sea-level rise, mixed forests, and aggressive tree trimming to reduce outages from hurricane-force winds and post-tropical storms.
Key Points
A strategy to harden grids, protect coasts, and manage forests to limit hurricane damage across Atlantic Canada.
✅ Grid hardening and selective undergrounding to cut outage risk.
✅ Coastal defenses: seawalls, dikes, and shoreline vegetation upgrades.
✅ Mixed forests and proactive tree trimming to reduce windfall damage.
In an era when storms with hurricane-force winds are expected to keep battering Atlantic Canada, experts say the region should make major changes to electrical grids, power utilities and shoreline defences and even the types of trees being planted.
Work continues today to reconnect customers after post-tropical storm Dorian knocked out power to 80 per cent of homes and businesses in Nova Scotia. By early afternoon there were 56,000 customers without electricity in the province, compared with 400,000 at the storm's peak on the weekend, a reminder that major outages can linger long after severe weather.
Recent scientific literature says 35 hurricanes -- not including post-tropical storms like Dorian -- have made landfall in the region since 1850, an average of one every five years that underscores the value of interprovincial connections like the Maritime Link for reliability.
Heavy rains and strong winds batter Shelburne, N.S. on Saturday, Sept. 7, 2019 as Hurricane Dorian approaches, making storm safety practices crucial for residents. (Suzette Belliveau/ CTV Atlantic)
Anthony Taylor, a forest ecologist scientist with Natural Resources Canada, wrote in a recent peer-reviewed paper that climate change is expected to increase the frequency of severe hurricanes.
He says promoting more mixed forests with hardwoods would reduce the rate of destruction caused by the storms.
Erni Wiebe, former director of distribution at Manitoba Hydro, says the storms should cause Atlantic utilities to rethink their view that burying lines is too expensive and to contemplate other long-term solutions such as the Maritime Link that enhance grid resilience.
Blair Feltmate, head of the Intact Centre on Climate Change at the University of Waterloo, says Atlantic Canada should also develop standards for coastline resiliency due to predictions of rising sea levels combining with the storms, while considering how delivery rate changes influence funding timelines.
He says that would mean a more rapid refurbishing of sea walls and dike systems, along with more shoreline vegetation.
Feltmate also calls for an aggressive tree-trimming program to limit power outages that he says "will otherwise continue to plague the Maritimes," while addressing risks like copper theft through better security.
Greengen Misfeasance Ruling details a B.C. Supreme Court decision awarding $10.125 million over wrongfully denied Crown land and water licence permits for a Fries Creek run-of-river hydro project under a BC Hydro contract.
Key Points
A B.C. Supreme Court ruling awarding $10.125M for wrongful denial of Crown land and water licences on Greengen's project.
✅ $10.125M damages for misfeasance in public office
✅ Denial of Crown land tenure and water licence permits
✅ Tied to Fries Creek run-of-river and BC Hydro EPA
A B.C. Supreme Court judge has ordered the provincial government to pay $10.125 million after it denied permits to a company that wanted to build a run-of-the river independent power project near Squamish.
In his Oct. 10 decision, Justice Kevin Loo said the plaintiff, Greengen Holdings Ltd., “lost an opportunity to achieve a completed and profitable hydro-electric project” after government representatives wrongfully exercised their legal authority, a transgression described in the ruling as “misfeasance,” with separate concerns reflected in an Ontario market gaming investigation reported elsewhere.
Between 2003 and 2009, the company sought to develop a hydro-electric project on and around Fries Creek, which sits opposite the Brackendale neighbourhood on the other side of the Squamish River. To do so, Greengen Holdings Ltd. required a water licence from the Minister of the Environment and tenure over Crown land from the Minister of Agriculture.
After a lengthy process involving extensive communications between Greengen and various provincial and other ministries and regulatory agencies, the permits were denied, according to Loo. Both decisions cited impacts on Squamish Nation cultural sites that could not be mitigated.
40-year electricity plan relied on Crown land The case dates back to December 2005, when BC Hydro issued an open call for power with Greengen. The company submitted a tender several months later.
On July 26, 2006, BC Hydro awarded Greengen an energy purchase agreement, amid evolving LNG electricity demand across the province, under which Greengen would be entitled to supply electricity at a fixed price for 40 years.
Unlike conventional hydroelectric projects, such as new BC generating stations recently commissioned, which store large volumes of water in reservoirs, and in so doing flood large tracts of land, a run of the river project often requires little or no water storage. Instead, from a high elevation, they divert water from a stream or river channel.
Water is then sent into a pressured pipeline known as a penstock, and later passed through turbines to generate electricity, Loo explained, as utilities pursue long-term plans like the Hydro-Québec strategy to reduce fossil fuel reliance. The system returns water to the original stream or river, or into another body of water.
The project called for most of that infrastructure to be built on Crown land, according to the ruling.
All sides seemed to support the project In early 2005, company principle Terry Sonderhoff discussed the Fries Creek project in a preliminary meeting with Squamish Nation Chief Ian Campbell.
“Mr. Sonderhoff testified that Chief Campbell seemed supportive of the project at the time,” Loo said.
Wall Street Fossil Fuel Pivot signals banks reassessing ESG, net-zero, and decarbonization goals, reviving oil, gas, and coal financing while recalibrating clean energy exposure amid policy shifts, regulatory rollbacks, and investment risk realignment.
Key Points
A shift as major U.S. banks ease ESG limits to fund oil, gas, coal while rebalancing alongside renewables.
✅ Banks revisit lending to oil, gas, and coal after policy shifts.
✅ ESG and net-zero commitments face reassessment amid returns.
✅ Renewables compete for capital as risk models are updated.
The global energy finance sector, worth a staggering $1.4 trillion, is undergoing a significant transformation, largely due to former President Donald Trump's renewed support for the oil, gas, and coal industries. Wall Street, which had previously aligned itself with global climate initiatives and the energy transition and net-zero goals, is now reassessing its strategy and pivoting toward a more fossil-fuel-friendly stance.
This shift represents a major change from the earlier stance, where many of the largest U.S. banks and financial institutions took a firm stance on decarbonization push, including limiting their exposure to fossil-fuel projects. Just a few years ago, these institutions were vocal supporters of the global push for a sustainable future, with many committing to support clean energy solutions and abandon investments in high-carbon energy sources.
However, with the change in administration and the resurgence of support for traditional energy sectors under Trump’s policies, these same banks are now rethinking their strategies. Financial institutions are increasingly discussing the possibility of lifting long-standing restrictions that limited their investments in controversial fossil-fuel projects, including coal mining, where emissions drop as coal declines, and offshore drilling. The change reflects a broader realignment within the energy finance sector, with Wall Street reexamining its role in shaping the future of energy.
One of the most significant developments is the Biden administration’s policy reversal, which emphasized reducing the U.S. carbon footprint in favor of carbon-free electricity strategies. Under Trump, however, there has been a renewed focus on supporting the traditional energy sectors. His administration has pushed to reduce regulatory burdens on fossil-fuel companies, particularly oil and gas, while simultaneously reintroducing favorable tax incentives for the coal and gas industries. This is a stark contrast to the Biden administration's efforts to incentivize the transition toward renewable energy and zero-emissions goals.
Trump's policies have, in effect, sent a strong signal to financial markets that the fossil-fuel industry could see a resurgence. U.S. banks, which had previously distanced themselves from financing oil and gas ventures due to the pressure from environmental activists and ESG (Environmental, Social, and Governance) investors, as seen in investor pressure on Duke Energy, are now reconsidering their positions. Major players like JPMorgan Chase and Goldman Sachs are reportedly having internal discussions about revisiting financing for energy projects that involve high carbon emissions, including controversial oil extraction and gas drilling initiatives.
The implications of this shift are far-reaching. In the past, a growing number of institutional investors had embraced ESG principles, with the goal of supporting the transition to renewable energy sources. However, Trump’s pro-fossil fuel stance appears to be emboldening Wall Street’s biggest players to rethink their commitment to green investing. Some are now advocating for a “balanced approach” that would allow for continued investment in traditional energy sectors, while also acknowledging the growing importance of renewable energy investments, a trend echoed by European oil majors going electric in recent years.
This reversal has led to confusion among investors and analysts, who are now grappling with how to navigate a rapidly changing landscape. Wall Street's newfound support for the fossil-fuel industry comes amid a backdrop of global concerns about climate change. Many investors, who had previously embraced policies aimed at curbing the effects of global warming, are now finding it harder to reconcile their environmental commitments with the shift toward fossil-fuel-heavy portfolios. The reemergence of fossil-fuel-friendly policies is forcing institutional investors to rethink their long-term strategies.
The consequences of this policy shift are also being felt by renewable energy companies, which now face increased competition for investment dollars from traditional energy sectors. The shift towards oil and gas projects has made it more challenging for renewable energy companies to attract the same level of financial backing, even as demand for clean energy continues to rise and as doubling electricity investment becomes a key policy call. This could result in a deceleration of renewable energy projects, potentially delaying the progress needed to meet the world’s climate targets.
Despite this, some analysts remain optimistic that the long-term shift toward green energy is inevitable, even if fossil-fuel investments gain a temporary boost. As the world continues to grapple with the effects of climate change, and as technological advancements in clean energy continue to reduce costs, the transition to renewables is likely to persist, regardless of the political climate.
The shift in Wall Street’s approach to energy investments, spurred by Trump’s pro-fossil fuel policies, is reshaping the $1.4 trillion global energy finance market. While the pivot towards fossil fuels may offer short-term gains, the long-term trajectory for energy markets remains firmly in the direction of renewables. The next few years will be crucial in determining whether financial institutions can balance the demand for short-term profitability with their long-term environmental responsibilities.
CO2 Tax for UK Offshore Energy Efficiency can accelerate adoption of aero-derivative gas turbines, flare gas recovery, and combined cycle power, reducing emissions on platforms like Equinor's Mariner and supporting net zero goals.
Key Points
A carbon price pushing operators to adopt efficient turbines, flare recovery, and combined cycle to cut emissions.
✅ Aero-derivative turbines beat industrial units on efficiency
✅ Flare gas recovery cuts routine flaring and fuel waste
✅ Combined cycle raises efficiency and lowers emissions
By Tom Baxter
The recent Energy Voice article from the Equinor chairman concerning the Mariner project heralding a ‘significant point of reference’ for growth highlighted the energy efficiency achievements associated with the platform.
I view energy efficiency as a key enabler to net zero, and alongside this the UK must start large-scale storage to meet system needs; it is a topic I have been involved with for many years.
As part of my energy efficiency work, I investigated Norwegian practices and compared them with the UK.
There were many differences, here are three;
1. Power for offshore installations is usually supplied from gas turbines burning fuel from the oil and gas processing plant, and even as the UK's offshore wind supply accelerates, installations convert that to electricity or couple the gas turbine to a machine such as a gas compressor.
There are two main generic types of gas turbine – aero-derivative and industrial. As the name implies aero-derivatives are aviation engines used in a static environment. Aero-derivative turbines are designed to be energy efficient as that is very import for the aviation industry.
Not so with industrial type gas turbines; they are typically 5-10% less efficient than a comparable aero-derivative.
Industrial machines do have some advantages – they can be cheaper, require less frequent maintenance, they have a wide fuel composition tolerance and they can be procured within a shorter time frame.
My comparison showed that aero-derivative machines prevailed in Norway because of the energy efficiency advantages – not the case in the UK where there are many more offshore industrial gas turbines.
Tom Baxter is visiting professor of chemical engineering at Strathclyde University and a retired technical director at Genesis Oil and Gas Consultants
2. Offshore gas flaring is probably the most obvious source of inefficient use of energy with consequent greenhouse gas emissions.
On UK installations gas is always flared due to the design of the oil and gas processing plant.
Though not a large quantity of gas, a continuous flow of gas is routinely sent to flare from some of the process plant.
In addition the flare requires pilot flames to be maintained burning at all times and, while Europe explores electricity storage in gas pipes, a purge of hydrocarbon gas is introduced into the pipes to prevent unsafe air ingress that could lead to an explosive mixture.
On many Norwegian installations the flare system is designed differently. Flare gas recovery systems are deployed which results in no flaring during continuous operations.
Flare gas recovery systems improve energy efficiency but they are costly and add additional operational complexity.
3. Returning to gas turbines, all UK offshore gas turbines are open cycle – gas is burned to produce energy and the very hot exhaust gases are vented to the atmosphere. Around 60 -70% of the energy is lost in the exhaust gases.
Some UK fields use this hot gas as a heat source for some of the oil and gas treatment operations hence improving energy efficiency.
There is another option for gas turbines that will significantly improve energy efficiency – combined cycle, and in parallel plans for nuclear power under the green industrial revolution aim to decarbonise supply.
Here the exhaust gases from an open cycle machine are taken to a separate turbine. This additional turbine utilises exhaust heat to produce steam with the steam used to drive a second turbine to generate supplementary electricity. It is the system used in most UK power stations, even as UK low-carbon generation stalled in 2019 across the grid.
Open cycle gas turbines are around 30 – 40% efficient whereas combined cycle turbines are typically 50 – 60%. Clearly deploying a combined cycle will result in a huge greenhouse gas saving.
I have worked on the development of many UK oil and gas fields and combined cycle has rarely been considered.
The reason being is that, despite the clear energy saving, they are too costly and complex to justify deploying offshore.
However that is not the case in Norway where combined cycle is used on Oseberg, Snorre and Eldfisk.
What makes the improved Norwegian energy efficiency practices different from the UK – the answer is clear; the Norwegian CO2 tax.
A tax that makes CO2 a significant part of offshore operating costs.
The consequence being that deploying energy efficient technology is much easier to justify in Norway when compared to the UK.
Do we need a CO2 tax in the UK to meet net zero – I am convinced we do. I am in good company. BP, Shell, ExxonMobil and Total are supporting a carbon tax.
Not without justification there has been much criticism of Labour’s recent oil tax plans, alongside proposals for state-owned electricity generation that aim to reshape the power market.
To my mind Labour’s laudable aims to tackle the Climate Emergency would be much better served by supporting a CO2 tax that complements the UK's coal-free energy record by strengthening renewable investment.
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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