A $66 million, 20-turbine wind farm is planned for Pike County in western Illinois.
Jacksonville-based cooperative Prairie Power says the farm could generate electricity for about 16,000 rural customers.
Construction at a site along the Illinois River about 70 miles west of Springfield would start next year. And electricity production would begin in 2011.
The co-op already operates a coal-fired power plant and natural-gas plant. But this is its first foray into wind energy.
Prairie Power executive Robert Reynolds says the co-op plans to sell clean-energy bonds to finance the project. The bonds include a federal tax credit.
Pike County currently has just one wind turbine, built in 2004.
Middle Tennessee Power Outages disrupt 100,000+ customers as severe thunderstorms, straight-line winds, downed trees, and debris challenge Nashville crews, slow restoration amid COVID-19, and threaten more hail, flash flooding, and damaging gusts.
Key Points
Blackouts across Nashville after severe storms and winds, leaving customers without power and facing restoration delays.
✅ Straight-line winds 60-80 mph toppled trees and power lines
✅ 130,000+ customers impacted; some outages may last 1-2 weeks
✅ Restoration slowed by debris, COVID-19 protocols, and new storms
Some middle Tennessee residents could be without electricity for up to two weeks after strong thunderstorms swept through the area Sunday, knocking out power for more than 100,000 customers, a scale comparable to Los Angeles outages after a station fire.
"Straight line winds as high as 60-80 miles per hour knocked down trees, power lines and power polls, interrupting power to 130,000 of our 400,000+ customers," Nashville Electric said in a statement Monday. The utility said the outage was one of the largest on record, though Carolina power outages recently left a quarter-million without power as well.
"Restoration times will depend on individual circumstances. In some cases, power could be out for a week or two" as challenges related to coronavirus and the need for utilities adapt to climate change complicated crews' responses and more storms were expected, the statement said. "This is unfortunate timing on the heels of a tornado and as we deal with battling COVID-19."
Metropolitan Nashville and Davidson County Mayor John Cooper also noted that the power outages were especially inconvenient, a challenge similar to Hong Kong families without power during Typhoon Mangkhut, as people were largely staying home to slow the spread of coronavirus. He also pointed out that the storms came on the two month anniversary of the Nashville tornado that left at least two dozen people dead.
"Crews are working diligently to restore power and clear any debris in neighborhoods," Cooper said.
He said that no fatalities were reported in the county but sent condolences to Spring Hill, whose police department reported that firefighter Mitchell Earwood died during the storm due to "a tragic weather-related incident" while at his home and off duty. He had served with the fire department for 10 years.
The Metro Nashville Department of Public Works said it received reports of more than 80 downed trees in Davidson County.
Officials also warn that copper theft can be deadly when electrical infrastructure is damaged after storms.
The National Weather Service Nashville said a 72 mph wind gust was measured at Nashville International Airport — the fifth fastest on record.
The weather service warned that strong storms with winds of up to 75 mph, large hail, record-long lightning bolt potential seen in the U.S., and isolated flash flooding could hit middle Tennessee again Monday afternoon and night.
"Treat Severe Thunderstorm Warnings the same way you would Tornado Warnings and review storm safety tips before you JUST TAKE SHELTER," the NWS instructs. "70 mph is 70 mph whether it's spinning around in a circle or blowing in a straight line."
Germany energy liquidity crisis is straining municipal utilities as gas and power prices surge, margin calls rise, and Russian supply cuts bite, forcing state support, interventions, and emergency financing to stabilize households and businesses.
Key Points
A cash squeeze on German municipal utilities as soaring gas and power prices trigger margin calls and funding gaps.
✅ Margin calls and spot-market purchases strain cash flow
✅ State liquidity lines and EU collateral support proposed
Germany’s fears that soaring power prices and gas prices could trigger a deeper crisis is starting to get real.
Several hundred local utilities are coming under strain and need support, according to the head of Germany’s largest energy lobby group. The companies, generally owned by municipalities, supply households and small businesses directly and are a key part of the country’s power and gas network.
“The next step from the government and federal states must be to secure liquidity for these municipal companies,” Kerstin Andreae, chairwoman of the German Association of Energy and Water Industries, told Bloomberg in Berlin. “Prices are rising, and they have no more money to pay the suppliers. This is a big problem.”
Germany’s energy crunch intensified over the weekend after Russia’s Gazprom PJSC halted its key gas pipeline indefinitely, a stark wake-up call for policymakers to reduce fossil fuel dependence. European energy prices have surged again amid concerns over shortages this winter and fears of a worst-case energy scenario across the bloc.
Many utilities are running into financial issues as they’re forced to cover missing Russian deliveries with expensive supplies on the spot market. German energy giant Uniper SE, which supplies local utilities, warned it will likely burn through a 7 billion-euro ($7 billion) government safety net and will need more help already this month.
Some German local utilities have already sought help, according to a government official, who asked not to be identified in line with briefing rules.
With Europe’s largest economy already bracing for recession, Chancellor Olaf Scholz’s administration is battling on several fronts, testing the government’s financial capacity. The ruling coalition agreed Sunday on a relief plan worth about 65 billion euros -- part of an emerging energy shield package to contain the fallout of surging costs for households and businesses.
Starting in October, local utilities will have to pay a levy for the gas acquired, which will further increase their financial burden, Andreae said.
Margin Calls European gas prices are more than four times higher than usual for this time of year, underscoring why rolling back electricity prices is tougher than it appears for policymakers, as Russia cuts supplies in retaliation for sanctions related to its invasion of Ukraine. When prices peak, energy companies have to pay margin calls, extra collateral required to back their trades.
Read more: Energy Trade Risks Collapsing Over Margin Calls of $1.5 Trillion
The problem has hit local utilities in other countries as well. In Austria, the government approved a 2 billion-euro loan for Vienna’s municipal utility last month.
The European Union is also planning help, floating gas price cap strategies among other tools. The bloc’s emergency measures will include support for electricity producers struggling to find enough cash to guarantee trades, according to European Commission President Ursula von der Leyen.
The situation has worsened in Germany as some of the country’s big gas importers are reluctant to sell more supplies to some of municipal companies amid fears they could default on payments, Andreae said.
U.S. Wind Generation surpassed hydroelectric output in 2019, EIA data shows, becoming the top renewable electricity source, driven by PTC incentives, expanded capacity, and utility-scale projects across states, boosting the national electricity mix.
Key Points
U.S. Wind Generation is the nation's top renewable, surpassing hydro as EIA-tracked capacity grows under PTC incentives.
✅ EIA: wind topped hydro in 2019, over 300M MWh generated
✅ PTC credits spurred growth in utility-scale wind projects
✅ 103 GW installed; 77% added in the last decade
Last year saw wind power surging in the U.S. to overtake hydroelectric generation for the first time, according to data from the U.S. Energy Information Administration (EIA).
Released Wednesday, the figures from the EIA’s “Electric Power Monthly” report show that yearly wind generation hit a little over 300 million megawatt hours (MWh) in 2019. This was roughly 26 million MWh more than hydroelectric production.
Wind now represents the “most-used renewable electricity generation source” in the U.S., the EIA said, and renewables hit a 28% monthly record in April in later data.
Overall, total renewable electricity generation — which includes sources such as solar's 4.7% share in 2022 as one example, geothermal and landfill gas — at utility scale facilities hit more than 720 million MWh in 2019, compared to just under 707 million MWh in 2018. To put things in perspective, generation from coal came to more than 966 million MWh in 2019, while renewables surpassed coal in 2022 nationally according to later analyses.
According to the EIA’s “Today in Energy” briefing, which was also published Wednesday, generation from wind power has grown “steadily” across the last decade, and by 2020, renewables became the second-most prevalent source in the U.S. power mix.
This, it added, was partly down to the extension of the Production Tax Credit, or PTC, amid favorable government plans supporting solar and wind growth. According to the EIA, the PTC is a system which gives operators a tax credit per kilowatt hour of renewable electricity production. It applies for the first 10 years of a facility’s operation.
At the end of 2019, the country was home to 103 gigawatts (GW) of wind capacity, with 77% of this being installed in the last decade, and wind capacity surpassed hydro in 2016 according to industry data. The U.S. is home 80 GW of hydroelectric capacity, according to the EIA.
“The past decade saw a steady increase in wind capacity across the country and we capped the decade with a monumental achievement for the industry in reaching more than 100 GW,” Tom Kiernan, the American Wind Energy Association’s CEO, said in a statement issued Thursday.
“And more wind energy is coming, as the industry is well into investing $62 billion in new projects over the next few years that put us on the path to achieving 20 percent of the nation’s electricity mix in 2030,” Kiernan went on to state.
“As a result, wind is positioned to remain the largest renewable energy generator in the country for the foreseeable future.”
California Rooftop Solar Rate Reforms propose shifting net metering to fixed access fees, peak-demand charges, and time-of-use pricing, aligning grid costs, distributed generation incentives, and retail rates for efficient, least-cost electricity and fair cost recovery.
Key Points
Policies replacing net metering with fixed fees, demand charges, and time-of-use rates to align costs and incentives.
✅ Large fixed access charge funds grid infrastructure
✅ Peak-demand pricing reflects capacity costs at system peak
✅ Time-varying rates align marginal costs and emissions
The California Public Service Commission has proposed revamping electricity rates for residential customers who produce electricity through their rooftop solar panels. In a recent New York Times op‐ed, former Governor Arnold Schwarzenegger argued the changes pose an existential threat to residential rooftop solar. Interest groups favoring rooftop solar portray the current pricing system, often called net metering, in populist terms: “Net metering is the one opportunity for the little guy to get relief, and they want to put the kibosh on it.” And conventional news coverage suggests that because rooftop solar is an obvious good development and nefarious interests, incumbent utilities and their unionized employees, support the reform, well‐meaning people should oppose it. A more thoughtful analysis would inquire about the characteristics and prices of a system that supplies electricity at least cost.
Currently, under net metering customers are billed for their net electricity use plus a minimum fixed charge each month. When their consumption exceeds their home production, they are billed for their net use from the electricity distribution system (the grid) at retail rates. When their production exceeds their consumption and the excess is supplied to the grid, residential consumers also are reimbursed at retail rates. During a billing period, if a consumer’s production equaled their consumption their electric bill would only be the monthly fixed charge.
Net metering would be fine if all the fixed costs of the electric distribution and transmission systems were included in the fixed monthly charge, but they are not. Between 66 and 77 percent of the expenses of California private utilities do not change when a customer increases or decreases consumption, but those expenses are recovered largely through charges per kWh of use rather than a large monthly fixed charge. Said differently, for every kWh that a PG&E solar household exported into the grid in 2019, it saved more than 26 cents, on average, while the utility’s costs only declined by about 8 cents or less including an estimate of the pollution costs of the system’s fossil fuel generators. The 18‐cent difference pays for costs that don’t change with variation in a household’s consumptions, like much of the transmission and distribution system, energy efficiency programs, subsidies for low‐income customers, and other fixed costs. Rooftop solar is so popular in California because its installation under a net metering system avoids the 18 cents, creating a solar cost shift onto non-solar customers. Rooftop solar is not the answer to all our environmental needs. It is simply a form of arbitrage around paying for the grid’s fixed costs.
What should electricity tariffs look like? This article in Regulation argues that efficient charges for electricity would consist of three components: a large fixed charge for the distribution and transmission lines, meter reading, vegetation trimming, etc.; a peak‐demand charge related to your demand when the system’s peak demand occurs to pay for fixed capacity costs associated with peak use; and a charge for electricity use that reflects the time‐ and location‐varying cost of additional electricity supply.
Actual utility tariffs do not reflect this ideal because of political concerns about the effects of large fixed monthly charges on low‐income customers and the optics of explaining to customers that they must pay 50 or 60 dollars a month for access even if their use is zero. Instead, the current pricing system “taxes” electricity use to pay for fixed costs. And solar net metering is simply a way to avoid the tax. The proposed California rate reforms would explicitly impose a fixed monthly charge on rooftop solar systems that are also connected to the grid, a change that could bring major changes to your electric bill statewide, and would thus end the fixed‐cost avoidance. Any distributional concerns that arise because of the effect of much larger fixed charges on lower‐income customers could be managed through explicit tax deductions that are proportional to income.
The current rooftop solar subsidies in California also should end because they have perverse incentive effects on fossil fuel generators, even as the state exports its energy policies to neighbors. Solar output has increased so much in California that when it ends with every sunset, natural gas generated electricity has to increase very rapidly. But the natural gas generators whose output can be increased rapidly have more pollution and higher marginal costs than those natural gas plants (so called combined cycle plants) whose output is steadier. The rapid increase in California solar capacity has had the perverse effect of changing the composition of natural gas generators toward more costly and polluting units.
The reforms would not end the role of solar power. They would just shift production from high‐cost rooftop to lower‐cost centralized solar production, a transition cited in analyses of why electricity prices are soaring in California, whose average costs are comparable with electricity production in natural gas generators. And they would end the excessive subsidies to solar that have negatively altered the composition of natural gas generators.
Getting prices right does not generate citizen interest as much as the misguided notion that rooftop solar will save the world, and recent efforts to overturn income-based utility charges show how politicized the debate remains. But getting prices right would allow the decentralized choices of consumers and investors to achieve their goals at least cost.
BC Hydro Rate Freeze Rejection details the BCUC decision enabling a 3% rate increase, citing revenue requirements, debt, and capital costs, affecting electricity bills, with NDP government proposing lifeline rates and low-income relief.
Key Points
It is the BCUC ruling allowing a 3% BC Hydro rate hike, citing cost recovery, debt, and capital needs.
✅ BCUC rejects freeze; 3% increase proceeds April 1, 2018
✅ Rationale: cost recovery, debt, capital expenditures
✅ Relief: lifeline rate, $600 grants, winter payment plan
The B.C. Utilities Commission has rejected a request by the provincial government to freeze rates at BC Hydro for the coming year, meaning a pending rate increase of three percent will come into effect as higher BC Hydro rates on April 1, 2018.
BC Hydro had asked for the three per cent increase, aligning with a rate increase proposal that would add about $2 a month, but, last year, Energy Minister Michelle Mungall directed the Crown corporation to resubmit its request in order to meet an NDP election promise.
"After years of escalating electricity costs, British Columbians deserve a break on their bills," she said at the time.
However, the utilities commission found there was "insufficient regulatory justification to approve the zero per cent rate increase."
"Even these increases do not fully recover B.C. Hydro's forecast revenue requirement, which includes items such as operating costs, new capital expenditures and carrying costs on capital expenditures," the commission wrote in a news release.
Mungall said she was disappointed by the decision.
"We were always clear we were going to the BCUC. We need to respect the role the BCUC has here for the ratepayers and for the public. I'm very disappointed obviously with their decision."
Mungall blamed the previous government for leaving BC Hydro in a financial state where a rate freeze was ultimately not possible.
Last month, Moody's Investors Service calculated BC Hydro's total debt at $22 billion and said it was one of the province's two credit challenges going forward.
"There's quite a financial mess that is a B.C. Liberal legacy after 16 years of government. We have the responsibility as a new government to clean that up."
B.C. Liberal leader Andrew Wilkinson said it was an example of the new government not living up to its campaign promises.
"British Columbians, particularly those on fixed incomes, believed the B.C. NDP when they promised a freeze on hydro bills. They planned accordingly and are now left in the lurch and face higher expenses. This is a government that stumbles into messes that cost all of us because they put rhetoric ahead of planning," he said.
Help on the way?
With the freeze being rejected, Mungall said the government would be going forward on other initiatives to help low-income ratepayers, as advocates' call for change after a fund surplus, including:
Legislating a "lifeline rate" program, allowing people with "demonstrated need" to apply for a lower rate for electricity.
Starting in May, providing an emergency grant of $600 for customers who have an outstanding BC Hydro bill.
Hydro's annual winter payment plan also allows people the chance to spread the payment of bills from December to February out over six months, and, with a two-year rate increase on the horizon, a new pilot program to help people paying their bills begins in July.
Mungall couldn't say whether the government would apply for rate freezes in the future.
"I don't have a crystal ball, and can't predict what might happen in two or three years from now, but we need to act swiftly now," she said.
"I appreciate the [BCUC's] rationale, I understand it, and we'll be moving forward with other alternatives for making life more affordable."
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.
