Building on its 90-year
history as CalgaryÂ’s electricity
distributor, ENMAX Corporation recently
introduced a host of new
electricity-related products and services for
commercial, industrial and
residential customers.
"WeÂ’ve offered a variety of products for
several years, others are brand-new to
the market - and this is just the beginning,"
said Sean Durfy, vice-president
and chief operating officer for ENMAX Energy
Corporation, a wholly owned,
unregulated subsidiary of ENMAX.
ENMAXÂ’s extensive slate of products and services include:
Power Partners - Informed decisions about
using and managing energy to optimize operations and make the most
of pricing options.
Power Services - Expertise in design,
installation and maintenance of power service equipment, using the most
advanced technology.
Electronic Services - Including security
systems, radio communication, audio/video systems and
system integration and maintenance services.
Bright Nights - A full service, turn-key
program providing complete outdoor lighting and maintenance systems
for roadway, civic, business and residential development needs.
"Full deregulation is coming to Alberta in 2001
and weÂ’re positioned to succeed in the competitive marketplace," Mr.
Durfy said. "We have several additional products in various stages of
development that we expect to make available later this year and in 2001."
According to recent surveys, ENMAX is one of
the most reliable electricity
distributors in Canada and its customer
satisfaction rating stands at more
than 80 per cent. The ENMAX transmission and
distribution system includes
about 2,700 kilometres of overhead and
underground wires and 32
substations. The company also maintains more
than 65,000 streetlights.
ENMAX Corporation, a wholly owned subsidiary of
The City of Calgary,
provides electricity and value-added services
to more than 320,000 residential,
commercial and industrial customers in Calgary
and surrounding areas.
Please visit our website at http://www.emax.com
Ontario Global Adjustment Deferral provides COVID-19 relief to industrial and commercial electricity consumers, holding GA charges at pre-COVID levels, aligning Class A and Class B rates, and deferring non-RPP costs from April to June 2020.
Key Points
An emergency measure that defers a portion of GA charges to stabilize electricity bills for non-RPP Class A/B consumers.
✅ Holds GA near pre-COVID levels at $115/MWh for Class B.
✅ Applies equal percentage relief to Class A customers.
✅ Deferred costs recovered over 12 months from Jan 2021.
Through an emergency order passed today, the Ontario government is taking steps to defer a portion of Global Adjustment (GA) charges for industrial and commercial electricity consumers that do not participate in the Regulated Price Plan for the period starting from April 2020, at a time when Toronto's growing electricity needs require careful planning. This initiative is intended to provide companies with temporary immediate relief on their monthly electricity bills, as utilities use AI to adapt to shifting electricity demands in April, May and June 2020. The government intends to keep this emergency order in place until May 31, 2020, and subsequent regulatory amendments would, if approved, provide for the deferral of these charges for June 2020 as well.
This relief will prevent a marked increase in Global Adjustment charges due to the low electricity demand caused by the COVID-19 outbreak. Without this emergency order, a small industrial or commercial consumer (i.e., Class B) could have seen bills increase by 15 per cent or more. This emergency order will hold GA rates in line with pre-COVID-19 levels, even as clean energy initiatives in British Columbia accelerate across the sector.
"Ontario's industrial and commercial electricity consumers are being impacted by COVID-19. They employ thousands of hardworking Ontarians, and we know this is a challenging time for them," said Greg Rickford, Minister of Energy, Northern Development and Mines. "This would provide immediate financial support for more than 50,000 companies when they need it most: as they do their part to stop the spread of COVID-19 and as they prepare to help get our economy moving again with Toronto preparing for a surge in electricity demand in the years ahead."
Quick Facts
The GA rate for smaller industrial and commercial consumers (i.e., Class B) has been set at $115 per megawatt-hour, which is roughly in line with the March 2020 value, alongside efforts to develop IoT security standards for electricity sector devices today. Large industrial and commercial consumers (i.e., Class A) will receive the same percentage reduction in GA charges as Class B consumers.
Subject to the approval of subsequent amendments, deferred costs would be recovered over a 12-month period beginning in January 2021, amid increasing exposure to harsh weather across Canadian grids.
Birtle Transmission Line connects Manitoba Hydro to SaskPower, enabling 215 MW of clean hydroelectricity, improving grid reliability, supporting affordable rates, and advancing Green Infrastructure goals under the Investing in Canada Plan across Manitoba and Saskatchewan.
Key Points
A 46 km line moving up to 215 MW from Manitoba Hydro to SaskPower, improving reliability and supplying cleaner power.
✅ Enables interprovincial grid tie between Manitoba and Saskatchewan
✅ Delivers up to 215 MW of renewable hydroelectricity
✅ Supports affordable rates and lower GHG emissions
The federal government announced funding for the Birtle Transmission Line Monday morning.
The project will help Manitoba Hydro build a transmission line from Birtle South Station in the Municipality of Prairie View to the Manitoba–Saskatchewan border 46 kilometres northwest. Once completed, the new line will allow up to 215 megawatts of hydroelectricity to flow from the Manitoba Hydro power grid to the SaskPower power grid, similar to the Great Northern Transmission Line connecting Manitoba and Minnesota today.
The government said the transmission line would create a more stable energy supply, keep energy rates affordable and help Saskatchewan's efforts to reduce cumulative greenhouse-gas emissions in that province.
"The Government of Canada is proud to be working with Manitoba to support projects that create jobs and improve people's lives across the province. The Birtle Transmission Line will provide the region with reliable and greener energy, as seen with Canadian hydropower to New York projects, that will help protect our environment while laying the groundwork for clean economic growth," said Jim Carr, member of Parliament for Winnipeg South Centre, on behalf of Catherine McKenna, minister of infrastructure and communities.
The Government of Canada is investing more than $18.7 million, and the government of Manitoba is contributing more than $42 million in this project through the Green Infrastructure Stream of the Investing in Canada Plan, which also supports Atlantic grid improvements nationwide.
"The Province of Manitoba has one of the cleanest electricity grids in Canada and the world with over 99 per cent of our electricity generated from clean, renewable sources, rooted in Manitoba's hydro history," said Central Services Minister Reg Helwer. "The Made-in-Manitoba Climate and Green Plan is good not only for Manitoba but for Canada and globally."
Jay Grewal, president, and CEO of Manitoba Hydro said the funding is a great example of co-operation between the provincial and federal governments, including investments in smart grid technology that modernize local networks.
"We are very pleased that Manitoba Hydro's Birtle Transmission Project is among the first projects to receive funding under the Canada Infrastructure Program, and we would like to thank both levels of governments for recognizing the importance of the project as we strengthen ties with our neighbours in Saskatchewan, as U.S.-Canada transmission approvals advance elsewhere," said Grewal.
A spokesperson for Manitoba Hydro said it’s too early to say how many jobs will be created during construction, as final contracts have not yet been awarded.
Ontario Electricity Billing Changes include OEB-backed shifts to time-of-use or tiered pricing, landlord blanket elections, LDC implementation guidance, a customer choice webpage with a bill calculator, and ENDM rate mitigation messaging.
Key Points
They are OEB measures enabling TOU-to-tiered switching, landlord elections, LDC guidance, and ENDM bill messages.
✅ Option to switch from TOU to tiered pricing
✅ Landlord blanket elections on tenant turnover
✅ ENDM-led bill info and rate mitigation messaging
By David Stevens, Aird & Berlis LLP
Electricity consumers in Ontario may see a couple of electricity rate changes in their bills in the coming months.
First, as we have already discussed, as of November 1, 2020, regulated price plan customers will have the option to switch to "tiered pricing" instead of time-of-use (TOU) pricing structures. Those who switch to "tiered pricing" will see changes in their electricity bills.
The Ontario Energy Board (OEB) has now issued final amendments to the Standard Supply Service Code to support the customer election process necessary to switch from TOU pricing to tiered pricing. The main change from what was already published in previous OEB notices is that landlords will be permitted to make a "blanket election" between TOU pricing and tiered pricing that will apply each time a tenant's account reverts back to the landlord on turnover of the rental unit. In its most recent notice, the OEB acknowledges that implementing the new customer billing option as of Nov. 1 (less than two months from now) will be challenging and directs Local Distribution Companies (LDCs) who cannot meet this date to be immediately in touch with the OEB. Finally, the OEB indicates that there will be a dedicated "customer choice webpage for consumers, including a bill calculator" in place by early October.
Second, as of January 1, 2021 low-volume consumers will see additional messaging on their bills to inform them of available rate mitigation programs.
A recent proposal posted on Ontario's Regulatory Registry indicates that the Ministry of Energy, Northern Development and Mines (ENDM) proposes that LDCs and Utility Sub-Meter Providers will be required to include a new on-bill message for low-volume consumers that "will direct customers to ENDM's new web page for further information about how the province provides financial support to electricity consumers." This new requirement is planned to be in place as of January 1, 2021. In conjunction with this requirement, the ENDM plans to launch a new web page that will provide "up-to-date information about electricity bills," including information about rate mitigation programs available to consumers. Parties are invited to submit comments on the ENDM proposal by October 5, 2020.
EU Clean Energy Transition underscores the shift from fossil fuels to renewable energy, decarbonization, and hydrogen, as soaring gas prices and electricity volatility spur resilience, storage, and joint procurement across the single market.
Key Points
EU Clean Energy Transition shifts from fossil fuels to renewables, enhancing resilience and reducing price volatility.
✅ Cuts reliance on Russian gas and fossil imports
✅ Scales renewables, hydrogen, and energy storage
✅ Stabilizes electricity prices via market resilience
Soaring energy prices, described as Europe's energy nightmare, are a stark reminder of how dependent Europe is on fossil fuels and should serve to accelerate the shift towards renewable forms of energy.
"This experience today of the rising energy prices is a clear wake up call... that we should accelerate the transition to clean energy, wean ourselves off the fossil fuel dependency," a senior EU official told reporters as the European Commission unveiled a series of emergency electricity measures aimed at tackling the crisis.
The European Union is facing a sharp spike in energy prices, driven by increased global demand as the world recovers from the pandemic and lower-than-expected natural gas deliveries from Russia. Wholesale electricity prices have increased by 200% compared to the 2019 average, underscoring why rolling back electricity prices is tougher than it appears, according to the European Commission.
"Winter is coming and for many electricity costs are larger than they have been for a decade," Energy Commissioner Kadri Simson told reporters on Wednesday.
80 million European households struggle to stay warm Wholesale gas prices — which have surged to record highs in France, Spain, Germany and Italy, amid reports of Germany's local utilities crying for help — are expected to remain high through the winter.
Prices are expected to fall in the spring, but remain higher than the average of past years, according to the Commission. Most EU countries rely on gas-fired power stations to meet electricity demand, and about 40% of that gas comes from Russia, with the EU outlining a plan to dump Russian energy to reduce this reliance, according to Eurostat.
Simson said that the Commission's initial assessment indicates that Russia's Gazprom has been fulfilling its long-term contracts "while providing little or no additional supply." Kremlin spokesman Dmitry Peskov told journalists on Wednesday that Russia has increased gas supplies to Europe to the maximum possible level under existing contracts, but could not exceed those thresholds. "We can say that Russia is flawlessly fulfilling all contractual obligations," he said.
Measures EU states can take to help consumers and businesses cope with soaring electricity costs include emergency income support to households to help them pay their energy bills, alongside potential gas price cap strategies, state aid for companies, and targeted tax reductions. Member states can also temporarily delay bill payments and put in place processes to ensure that no one is disconnected from the grid.
Green energy the solution The Commission also published a series of longer term measures the bloc should consider to reduce its dependence on fossil fuels and tackle energy price volatility, despite opposition from nine countries to electricity market reforms.
"Our immediate priority is to protect Europe's consumers, especially the most vulnerable," Simson said. "Second, we want to make our energy system better prepared and more resilient, so we don't have to face a similar situation in the future," she added.
Energy crisis could force more UK factories to close This would require speeding up the green energy transition rather than slowing it down, Simson said. "We are not facing an energy price surge because of our climate policy or because renewable energy is expensive. We are facing it because the fossil fuel prices are spiking," she continued.
"The only long term remedy against demand shocks and price volatility is a transition to a green energy system."
Simson said she will propose to EU leaders a package of measures to decarbonize Europe's gas and hydrogen markets by 2050. Other measures to improve energy market stability could include increasing gas storage capacity and buying gas jointly at an EU level.
South Carolina Energy Freedom Act lifts net metering caps, reforms PURPA, and overhauls utility planning to boost solar competition, grid resiliency, and consumer choice across the Southeast amid Santee Cooper debt and utility monopoly pressure.
Key Points
A bipartisan reform lifting net metering caps, modernizing PURPA, and updating utility planning to expand solar.
✅ Lifts net metering cap to accelerate rooftop and community solar.
✅ Reforms PURPA contracts to enable fair pricing and transparent procurement.
✅ Modernizes utility IRP and opens markets to competition and customer choice.
The South Carolina House has approved the latest version of the Energy Freedom Act, a bill that overhauls the state’s electricity policies, including lifting the net metering caps and reforming PURPA implementation and utility planning processes in a way that advocates say levels the playing field for solar at all scales.
With Governor Henry McMaster (R) expected to sign the bill shortly, this is a major coup not just for solar in the state, but the region. This is particularly notable given the struggle that solar has had just to gain footing in many parts of the South, which is dominated by powerful utility monopolies and conservative politicians.
Two days ago when the bill passed the Senate we covered the details of the policy, but today we’re going to take a look at the politics of getting the Energy Freedom Act passed, and what this means for other Southern states and “red” states.
Opportunity amid crisis
The first thing to note about this bill is that it comes within a crisis in South Carolina’s electricity sector. This was the first legislative session following state-run utility Santee Cooper’s formal abandonment of a project to build two new reactors at the Virgil C. Sumner nuclear power plant, on which work stopped nearly two years ago.
Santee Cooper still holds $4 billion in construction debt related to the nuclear projects. According to an article in The State, this is costing its customers $5 per month toward the current debt, and this will rise to $13 per month for the next 40 years.
Such costs are particularly unwelcome in South Carolina, which has the highest annual electricity bills in the nation due to a combination of very high electricity usage driven by widespread air conditioning during the hot summers and higher prices per unit of power than other Southern states.
Following this fiasco, Santee Cooper’s CEO has stepped down, and the state government is currently considering selling the utility to a private entity. According to Maggie Clark, southeast state affairs senior manager for Solar Energy Industries Association, all of this set the stage for the bill that passed today.
“South Carolina is in a really ripe state for transformational energy policy in the wake of the VC Sumner nuclear plant cancellation,” Clark told pv magazine. “They were looking for a way forward, and I think this bill really provided them something to champion.”
Renewable energy policy for red states
This major win for solar policy comes in a state where the Republican Party holds majorities in both houses of the state’s legislature and sends bills to a Republican governor.
Broadly speaking, Republican politicians seldom show the level of interest in supporting renewable energy that Democrats do either at the state or national level, and show even less inclination to act to address greenhouse gas emissions. In fact, the 100% clean energy mandates that are being implemented in four states and Washington D.C. have only passed with Democratic trifectas, in other words with Republicans controlling neither house of the state legislature nor the governor’s office. (Note: This does not apply to Puerto Rico, which has a different party structure to the rest of the United States)
However, South Carolina shows there are Republican politicians who will support pro-renewable energy policies, and circumstances under which Republican majorities will vote for legislation that aids the adoption of solar. And these specific circumstances speak to both different priorities and ideological differences between the two parties.
SEIA’s Maggie Clark emphasizes that the Energy Freedom Act was about reforming market rules. “This was a way to provide a program that did not provide subsidies or incentives in any way, but to really open the market to competition,” explains Clark. “I think that appealing to conservatives in the South about energy independence and resiliency and ultimately cost savings is the winning message on this issue.”
Such messaging in South Carolina is not an accident. Not only has such messaging been successful in the past, but coalition partner Vote Solar paid for polling to find what messages resounded with the state’s voters, and found that choice and competition were likely to resound.
And all of this happened in the context of what Clark describes as an “extremely well-resourced effort”, with SEIA in particular dedicating national attention and resources to the state – as part of an effort by President and CEO Abigail Hopper to shift attention more towards state-level policy. Maggie Clark is one of two new regional staff who Hopper has hired, and SEIA’s first staff member focused on Southern states.
“Absolutely the South is a prioritized region,” Hopper told pv magazine, noting that three Southern states – the Carolinas and Florida – are among the 12 states that the organization has identified to work on this year. “It became clear that as a region it needed more attention.”
SEIA is not expecting fly-by-night victories, and Hopper attributes the success in South Carolina not only to a broad coalition, but to years of work on the ground in the state.
Nor is SEIA the only organization to grow its presence in the region. Vote Solar now has two full time staff located in the South, whereas two years ago its sole staff member dedicated to the region was located in Washington D.C.
Ideology versus reality in the South
The Energy Freedom Act aligns with conservative ideas about small government and competition, but the American right is not monolithic, nor do political ideas and actions always line up neatly, as other successful policies in other states in the region show
By far the largest deployment of renewable energy in the nation has been in Texas, aside from in California which leads overall. Here a system of renewable energy zones in the sparsely populated but windy and sunny west, north and center of the state feed cities to the east with power from wind and more recently solar.
This was enabled by transmission lines whose cost was socialized among the state’s ratepayers – a tremendous irony given that the state’s politicians would be some of the last in the nation to want to be identified with socializing anything.
Another example is Louisiana, which saw a healthy residential solar market over the last decade due to a 50% state rebate. The policy has expired, but when operating it was exactly the sort of outright subsidy that right-wing media and politicians rail against.
Of course there is also North Carolina, which built the 2nd-largest solar market in the nation on the back of successful state-level implementation of PURPA, a federal law. Finally there is Virginia, where large-scale projects are booming following a 2018 law that found that 5 GW of solar is in the public interest.
Furthermore, while conservatives continually expound the virtues of the free market, the reality of the electricity sector in the “deep red” South is anything but that. The region missed out on the wave of deregulation in the 1990s, and remains dominated by monopoly utilities regulated by the state: a union of big business and big government where competition is non-existent.
This has also meant that the solar which has been deployed in the South is mostly not the kind of rooftop solar that many think of as embodying energy independence, but rather large-scale solar built in farms, fields and forests.
Where to from here?
With such contradictions between stated ideology and practice, it is less clear what makes for successful renewable energy policy in the South. However, opening up markets appears to be working not only in South Carolina, but also in Florida, where third-party solar companies are making inroads after the state’s voters rejected a well-funded and duplicitous utilities’ campaign to kill distributed solar.
SEIA’s Hopper says that she is “aggressively optimistic” about solar in Florida. As utilities have dominated large-solar deployment in the state, even as the state declined federal solar incentives earlier this year, she says that she sees opening up the state’s booming utility-scale solar market to competition as a priority.
Some parts of the region may be harder than others, and it is notable that SEIA has not had as much to say about Alabama, Mississippi or Louisiana, which are largely controlled by utility giants Southern Company and Entergy, or the area under the thumb of the Tennessee Valley Authority, one of the most anti-solar entities in the power sector.
Abby Hopper says ultimately, demand from customers – both individuals and corporations – is the key to transforming policy. “You replicate these victories by customer demand,” Hopper told pv magazine. “That combination of voices from the customer are what’s going to drive change.”
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.
