The New York Independent System Operator (NYISO) will incorporate a centralized wind forecasting system to better accommodate wind power in New YorkÂ’s bulk electricity grid.
The wind-forecasting system, planned for implementation this summer, is one of many steps being taken by the NYISO to recognize and incorporate the unique characteristics and variable nature of wind power in dispatching resources to economically serve the StateÂ’s electric load.
The NYISO has contracted with AWS Truewind, of Colonie, N.Y., to implement the wind-forecasting capability. The ability to more accurately forecast wind allows the NYISO to gauge how much wind power is likely to be available throughout a given day, enabling maximum use of “green power” resources while enhancing reliability by anticipating variations in generator output.
“As fuel costs climb and the need for emission-free electricity grows, it is important to realize the full potential of renewable energy resources such as wind. The NYISO is committed to accommodating the market entry of any and all new technologies and renewable resources,” said Karen Antion, the NYISO’s Board Chair and interim CEO.
“As more wind power projects are connected to the grid, they will require enhanced attention. The advance forecasts will allow us to accommodate wind power more accurately and reliably,” said Robert Hiney, a NYISO Board member and interim President.
The variable nature of wind generation poses special challenges to grid operators, such as the NYISO, who must constantly balance the supply of and demand for electricity on the grid because electricity cannot be stored efficiently with current technologies.
To produce the forecasts, wind generators will send meteorological data and the NYISO will send power data to AWS Truewind. The company will provide wind power forecasts to the NYISO, which will use the information to integrate wind power in balancing the supply of electricity with consumer demand.
The NYISO has also proposed wind-related revisions in market rules, which are subject to approval by the Federal Energy Regulatory Commission (FERC). The proposals include:
• Increasing the amount of wind generation eligible for exemption from under-generation penalties and full compensation for over-generation,
• Requiring wind projects to finance the costs of the centralized forecasting service, and
• Establishing penalties for wind generators who continually fail to deliver meteorological data to the NYISO forecaster.
Currently, there are nearly 500 megawatts of wind generating capacity in commercial operation in New York State. Almost 7,000 megawatts of proposed wind generation projects are proceeding through the grid interconnection process administered by the NYISO.
According to the American Wind Energy Association (AWEA), independently operated wholesale electricity markets, such as those administered by the NYISO, are enabling greater amounts of wind power to be integrated into the nationÂ’s electric grid. In 2007, AWEA reported that regions served by independently operated wholesale electricity markets had approximately 73 percent of installed wind capacity, despite having only 44 percent of nationÂ’s wind power potential.
Lockdown Electricity Demand Trends reveal later mornings, weaker afternoons, and delayed peaks as WFH, streaming, and video conferencing reshape energy demand curves, grid forecasting, and residential electricity usage across Europe, New York, Tokyo, and Singapore.
Key Points
Shifts in power use during lockdowns: later ramps, weaker afternoons, and higher, delayed evening peaks.
✅ WFH and streaming raise residential load; industrial demand falls
Life in lockdown means getting up late, staying up till midnight and slacking off in the afternoons.
That’s what power market data in Europe show in the places where restrictions on activity have led to a widespread shift in daily routines of hundreds of millions of people.
It’s a similar story wherever lockdowns bite. In New York City electricity use has fallen as much as 18% from normal times at 8am. Tokyo and three nearby prefectures had a 5% drop in power use during weekdays after Japan declared a state of emergency on April 7, according to Tesla Asia Pacific, an energy forecaster.
Italy’s experience shows the trend most clearly since the curbs started there on March 5, before any other European country. Data from the grid operator Terna SpA gives a taste of what other places are also now starting to report, with global daily demand dips observed in many markets as well.
1. People are sleeping later
With no commute to the office people can sleep longer. Normally, electricity demand began to pick up between 6 a.m. and 8 a.m. Now in Germany, it’s clear coffee machines don’t go on until between 8 a.m. and 9 a.m., said Simon Rathjen, founder of the trading company MFT Energy A/S.
Germany, France and Italy -- which between them make up almost two thirds of the euro-zone economy -- all have furlough measures that allow workers to receive a salary while temporarily suspended from their jobs. The U.K. also has a support package. Many of these workers will be getting up later.
"Now I have quite a relaxed start to the morning,” said David Freeman, an analyst in financial services from London. "I don’t get up until about half an hour before I need to start work.”
2. Less productive afternoons
There is a deeper dip in electricity use in the afternoons. Previously, power use rose between 2pm and 5pm. Now it dips as people head out for a walk or some air, according to UK demand data from National Grid Plc
It’s "as though we are living through a month of Sundays”, said Iain Staffell, senior lecturer in sustainable energy at Imperial College London.
3. Evenings in
From 6pm electricity use begins to rise steeply as people finish work and start chores. Restrictions like work and home schooling that prevent much daytime TV watching lifts in the early evening. This following chart for Germany shows the evening peak for power use coming during later hours.
The evening is when electricity use is highest, with most people confined to their homes. Netflix Inc reported a record 15.8 million paid subscribers – almost double the figure forecast by Wall Street analysts. Video-streaming services like Netflix and YouTube have found a captive audience. The new Disney+ service surpassed 50 million subscribers in just five months, a faster pace than predicted.
Internet traffic is skyrocketing, with a surge in bandwidth-intensive applications like streaming services and Zoom. This may mean that monthly broadband consumption of as much as 600 gigabytes, about 35% higher than before, according to Bloomberg Intelligence.
In Singapore, electricity use has dropped off significantly since the country’s "circuit-breaker” efforts to keep people at home began April 7. Electricity use has fallen and stayed low during the day. But late at night is a different story, as power demand fell sharply immediately after the lockdown began, it has steadily crept back in the past two weeks, perhaps a sign that Tiger King and The Last Dance have been finding late-night fans in the city state.
In Ottawa, COVID-19 closures made it seem as if the city had fallen off the electricity grid, according to local reports.
4. Staying up late
We’re going to bed later too. Demand doesn’t start to drop off until 10pm to 12am, at least an hour later than before.
"My children are definitely going to bed later,” said Liz Stevens, a teaching assistant from London. "Our whole routine is out the window.”
It’s challenging for those that need to predict behaviour – power grids and electricity traders. Forecasting is based on historical data, and there isn’t anything to go into the models gauging use now.
The closest we can get is looking at big events like football World Championships when people are all sitting down at the same time, according to Rathjen at MFT.
"Forecasting demand right now is very tricky,” said Chris Kimmett, director of power grids at Reactive Technologies Ltd. "A global pandemic is uncharted territory."
What normal looks like when the crisis passes is also an open question. Different countries are set to unravel their measures in their own ways, and global power demand has already surged above pre-pandemic levels in some analyses, with Germany and Austria loosening restrictions first and Italy remaining under tight control. Some changes may be permanent, with both workers and employers becoming more comfortable with working from home.
5. Different sectors consume more
In China, which is further along recovering from the pandemic than Europe or the US, the sharp contraction in overall power output masks a shift in daily routines.
Eating habits have changed. Restaurants are expanding delivery and even offering grocery services as the preference for dining at home persists. Household electricity consumption in China probably increased from activities such as cooking and heating, according to IHS Markit, which said that residential demand rose by 2.4% in the first two months as people stayed in.
The increase in technology use also drove China’s power demand from the telecom and web-service sectors to rise by 27%, the consultancy said.
Overall, China power demand in the first quarter of the year fell 6.5% from the same period in 2019 to 1.57 trillion kilowatt-hours, China’s National Energy Administration said last week. Industry uses about 70% of the country’s electricity, while the commercial sector and households account for 14% each. – Bloomberg
Nighttime Thermoelectric Generator converts radiative cooling into renewable energy, leveraging outer space cold; a Stanford-UCLA prototype complements solar, serving off-grid loads with low-power output during peak evening demand, using simple materials on a rooftop.
Key Points
A device converting nighttime radiative cooling into electricity, complementing solar for low-power evening needs.
✅ Uses thermocouples to convert temperature gradients to voltage.
✅ Exploits radiative cooling to outer space for night power.
✅ Complements solar; low-cost parts suit off-grid applications.
Two years ago, one freezing December night on a California rooftop, a tiny light shone weakly with a little help from the freezing night air. It wasn't a very bright glow. But it was enough to demonstrate the possibility of generating renewable power after the Sun goes down.
Working with Stanford University engineers Wei Li and Shanhui Fan, University of California Los Angeles materials scientist Aaswath Raman put together a device that produces a voltage by channelling the day's residual warmth into cooling air, effectively generating electricity from thin air with passive heat exchange.
"Our work highlights the many remaining opportunities for energy by taking advantage of the cold of outer space as a renewable energy resource," says Raman.
"We think this forms the basis of a complementary technology to solar. While the power output will always be substantially lower, it can operate at hours when solar cells cannot."
For all the merits of solar energy, it's just not a 24-7 source of power, although research into nighttime solar cells suggests new possibilities for after-dark generation. Sure, we can store it in a giant battery or use it to pump water up into a reservoir for later, but until we have more economical solutions, nighttime is going to be a quiet time for renewable solar power.
Most of us return home from work as the Sun is setting, and that's when energy demands spike to meet our needs for heating, cooking, entertaining, and lighting.
Unfortunately, we often turn to fossil fuels to make up the shortfall. For those living off the grid, it could require limiting options and going without a few luxuries.
Shanhui Fan understands the need for a night time renewable power source well. He's worked on a number of similar devices, including carbon nanotube generators that scavenge ambient energy, and a recent piece of technology that flipped photovoltaics on its head by squeezing electricity from the glow of heat radiating out of the planet's Sun-warmed surface.
While that clever item relied on the optical qualities of a warm object, this alternative device makes use of the good old thermoelectric effect, similar to thin-film waste-heat harvesting approaches now explored.
Using a material called a thermocouple, engineers can convert a change in temperature into a difference in voltage, effectively turning thermal energy into electricity with a measurable voltage. This demands something relatively toasty on one side and a place for that heat energy to escape to on the other.
The theory is the easy part – the real challenge is in arranging the right thermoelectric materials in such a way that they'll generate a voltage from our cooling surrounds that makes it worthwhile.
To keep costs down, the team used simple, off-the-shelf items that pretty much any of us could easily get our hands on.
They put together a cheap thermoelectric generator and linked it with a black aluminium disk to shed heat in the night air as it faced the sky. The generator was placed inside a polystyrene enclosure sealed with a window transparent to infrared light, and linked to a single tiny LED.
For six hours one evening, the box was left to cool on a roof-top in Stanford as the temperature fell just below freezing. As the heat flowed from the ground into the sky, the small generator produced just enough current to make the light flicker to life.
At its best, the device generated around 0.8 milliwatts of power, corresponding to 25 milliwatts of power per square metre.
That might just be enough to keep a hearing aid working. String several together and you might just be able to keep your cat amused with a simple laser pointer. So we're not talking massive amounts of power.
But as far as prototypes go, it's a fantastic starting point. The team suggests that with the right tweaks and the right conditions, 500 milliwatts per square metre isn't out of the question.
"Beyond lighting, we believe this could be a broadly enabling approach to power generation suitable for remote locations, and anywhere where power generation at night is needed," says Raman.
While we search for big, bright ideas to drive the revolution for renewables, it's important to make sure we don't let the smaller, simpler solutions like these slip away quietly into the night.
Canadian Hydropower Transmission delivers HVDC clean energy via New England Clean Energy Connect and Champlain Hudson Power Express, linking HydroQuébec to Maine and New York grids for renewable energy, decarbonization, and lower wholesale electricity rates.
Key Points
HVDC delivery of HydroQuébec power to New England and New York via NECEC and CHPE, cutting emissions and costs.
✅ 1,200 MW via NECEC; 1,000 MW via CHPE.
✅ HVDC routes: 145-mile NECEC and 333-mile CHPE.
✅ Debates: land impacts, climate justice, wholesale rates.
As the sole residents of unorganized territory T5 R7 deep within Maine's North Woods, Duane Hanson and his wife, Sally Kwan, have watched the land around them—known for its natural beauty, diverse wildlife and recreational fishing—transformed by decades of development.
But what troubles them most is what could happen in the next few months. State and corporate officials are pushing for construction of a 53-mile-long power line corridor cutting right through the woods and abutting the wild lands surrounding Hanson's property.
If its proponents succeed, Hanson fears the corridor may represent the beginning of the end of his ability to live "off the land" away from the noise of technology-obsessed modern society. Soon, that noise may be in his backyard.
"I moved here to be in the pristine wilderness," said Hanson.
With his life in what he considers the last "wild" place left on the East Coast on the line, the stakes have never felt higher to Hanson—and many across New England, as well.
The corridor is part of the New England Clean Energy Connect, one of two major and highly controversial transmission line projects meant to deliver Canadian hydropower from the government-owned utility HydroQuébec, in a province that has closed the door on nuclear power, to New England electricity consumers.
As New England states rush to green their electric grids and combat the accelerating climate crisis, the simultaneous push from Canada to expand the market for hydroelectric power from its vast water resources, including Manitoba's clean energy, has offered these states a critical lifeline at just the right moment.
The other big hydropower transmission line project will deliver 1,000 megawatts of power, or enough to serve approximately one million residential customers, to the New York City metropolitan area, which includes the city, Long Island, and parts of the Hudson Valley, New Jersey, Connecticut and Pennsylvania.
The 333-mile-long Champlain Hudson Power Express project will consist of two high voltage direct current cables running underground and underwater from Canada, beneath Lake Champlain and the Hudson River, to Astoria, Queens.
There, the Champlain Hudson project will interconnect to a sector of the New York electricity grid where city and corporate officials say the hydropower supplied can help reduce the fossil fuels that currently comprise significantly more of the base load than in other parts of the state. Though New York has yet to finalize a contract with HydroQuébec over its hydropower purchase, developers plan to start construction on the $2.2 billion project in 2021 and say it will be operational in 2025.
The New England project consists of 145 miles of new HVDC transmission line that will run largely above ground from the Canadian border, through Maine to Massachusetts. The $1 billion project, funded by Massachusetts electricity consumers, is expected to deliver 1,200 megawatts of clean energy to the New England energy grid, becoming the region's largest clean energy source.
Central Maine Power, which will construct the Maine transmission corridor, says the project will decrease wholesale electric rates and create thousands of jobs. Company officials expect to receive all necessary permits and begin construction by the year's end, with the project completed and in service by 2020.
With only months until developers start making both projects on-the-ground realities, they have seized public attention within, and beyond, their regions.
Hanson is one among many concerned New England and New York residents who've joined the ranks of environmental activists in a contentious battle with public and corporate officials over the place of Canadian hydropower in their states' clean energy futures.
Officials and transmission line proponents say importing Canadian hydropower offers an immediate and feasible way to help decarbonize electricity portfolios in New York and New England and to address existing transmission constraints that limit cross-border flows today, supporting their broader efforts to combat climate change.
But some environmental activists say hydropower has a significant carbon footprint of its own. They fear the projects will make states look "greener" at the expense of the local environment, Indigenous communities, and ultimately, the climate.
"We're talking about the most environmentally and economically just pathway" to decarbonization, said Annel Hernandez, associate director of the NYC Environmental Justice Alliance. "Canadian hydro is not going to provide that."
To that end, environmental groups opposing Canadian hydropower say New York and New England should seize the moment to expedite local development of wind and solar power.
Paul Gallay, president of the nonprofit environmental organization Riverkeeper—which withdrew its initial support for the Champlain Hudson Power Express last November— believes New York has the capacity to develop enough in-state renewable energy sources to meet its clean energy goals, without the new transmission line.
Yet New York City's analysis shows clearly that Canadian hydropower is critical for its clean energy strategy, said Dan Zarrilli, director of OneNYC and New York City's chief climate policy adviser.
"We need every bit of clean energy we can get our hands on," he said, to meet the city's goal of carbon neutrality by 2050 and help achieve the state's clean energy mandates.
Removing Canadian hydropower from the equation, said Zarilli, would commit the city to the "unacceptable outcome" of burning more gas. The city's marginalized communities would likely suffer most from the resulting air pollution and associated health impacts.
While the two camps debate Canadian hydropower's carbon footprint and what climate justice requires, this much is clear: When it comes to pursuing a zero-carbon future, there are no easy answers.
Hydropower's Carbon Footprint Many people take for granted that because hydropower production doesn't involve burning fossil fuels, it's a carbon-neutral endeavor. But that's not always the case, depending on where hydropower is sourced.
Large-scale hydropower projects often involve the creation of hydroelectric dams and reservoirs, and, in some cases, repowering existing dams to generate clean electricity. The release and flow of water from the reservoir through the dam provides the energy necessary to generate hydropower, which long-distance power lines, or transmission lines, carry to its intended destination—in this case, New England and New York.
The initial process of flooding land to create a hydroelectric reservoir can have a sizable carbon footprint, especially in heavily vegetated areas. It causes the vegetation and soil underwater to decompose, releasing carbon dioxide and methane—a greenhouse gas 84 times more potent over a 20-year period than carbon dioxide.
Hydropower accounts for 60 percent of Canada's electricity generation, and HydroQuébec has planned to increase capacity to 37,000 MW in 2021, with the nation second only to China in the percentage of the world's total hydroelectricity it generates. By contrast, hydropower only accounts for seven percent of U.S. utility-scale electricity generation, making it a foreign concept to many Americans.
As New England works to introduce substantial amounts of Canadian hydropower to its electricity grid, hydropower proponents are promoting it as a prime source for clean electricity, and new NB Power agreements are expanding regional transfers within Canada as well.
Last fall, Central Maine Power formed its own political action committee, Clean Energy Matters, to advance the New England hydropower project. Together with HydroQuébec, the Maine utility has spent nearly $17 million campaigning for the project this year.
CPUC Decision on San Diego Community Power directs SDG&E to use updated forecasts, stabilizing electricity rates for CCA customers and supporting clean energy in San Diego with accurate rate forecasting and reduced volatility.
Key Points
A CPUC ruling directing SDG&E to use updated forecasts to ensure accurate, stable CCA rates and limit volatility.
✅ Uses 2021 sales forecasts for rate setting
✅ Aims to prevent undercollection and bill spikes
✅ Levels changes across customer classes
The California Public Utilities Commission on Thursday sided with the soon-to-launch San Diego community energy program in a dispute it had with San Diego Gas & Electric.
San Diego Community Power — which will begin to purchase power for customers in San Diego, Chula Vista, La Mesa, Encinitas and Imperial Beach later this year — had complained to the commission that data SDG&E intended to use to calculate rates, including community choice exit fees that could make the new energy program less attractive to prospective customers.
SDG&E argued it was using numbers it was authorized to employ as part of a general rate case amid a potential rate structure revamp that is still being considered by the commission.
But in a 4-0 vote, the commission, or CPUC, sided with San Diego Community Power and directed SDG&E to use an updated forecast for energy sales.
"This was not an easy decision," said CPUC president Marybel Batjer at the meeting, held remotely due to COVID-19 restrictions. "In my mind, this outcome best accounts for the shifting realities ... in the San Diego area while minimizing the impact on ratepayers during these difficult financial times."
In filings to the commission, SDG&E predicted a rate decrease of 12.35 percent in the coming year. While that appears to be good news for customers, Californians still face soaring electricity prices statewide, Commissioner Martha Guzman Aceves said the data set SDG&E wanted to use would lead to an undercollection of $150 million to $260 million.
That would result in rates that would be "artificially low," Guzman Aceves said, and rates "would inevitably go up quite a bit after the undercollection was addressed."
San Diego Community Power, or SDCP, said the temporary reduction would make its rates less attractive than SDG&E's, especially amid SDG&E's minimum charge proposal affecting low-usage customers, just as it is about to begin serving customers. SDCP's board members wrote an open letter last month to the commission, accusing the utility of "willful manipulation of data."
Working with an administrative law judge at the CPUC, Guzman Aceves authored a proposal requiring SDG&E to use numbers based on 2021 forecasts, as regulators simultaneously weigh whether the state needs more power plants to ensure reliability. The utility argued that could result in an increase of "roughly 40 percent" for medium and large commercial and industrial customers this year.
To help reduce potential volatility, Guzman Aceves, SDCP and other community energy supporters called for using a formula that would average out changes in rates across customer classes amid debates over income-based utility charges statewide. That's what the commissioners OK'd Thursday.
"It is essential that customer commodity rates be as accurate as we can possibly get them to avoid undercollections," said Commissioner Genevieve Shiroma.
San Diego Community Power is one of 23 community choice aggregation, or CCA, energy programs that have launched in California in the past decade.
CCAs compete with traditional power companies amid California's evolving power competition landscape, in one important role — purchasing power for a given community. They were created to boost the use of cleaner energy sources, such as wind and solar, at rates equal to or lower than investor-owned utilities.
However, CCAs do not replace utilities because the incumbent power companies still perform all of the tasks outside of power purchasing, such as transmission and distribution of energy and customer billing.
When a CCA is formed, California rules stipulate the utility customers in that area are automatically enrolled in the CCA. If customers prefer to stay with their previous power company, they can opt out of joining the CCA.
The shift of customers from SDG&E to San Diego Community Power is expected to be large. The total number of accounts for SDCP is expected to be 770,000, which would make it the second-largest CCA in the state. That's why SDCP considered Thursday's CPUC decision to be so important.
"At a time when customers are choosing between sticking with San Diego Gas & Electric and migrating to a CCA, we want them to have accurate bill information," said Commissioner Clifford Rechtschaffen.
"SDCP is very happy with today's CPUC decision, and that the commissioners shared our goal of limiting rate volatility for businesses and families in the region," said SDCP interim CEO Bill Carnahan. "This is definitely a win for accurate rate forecasting, and our mutual customers, and we look forward to working with SDG&E on next steps."
In an email, SDG&E spokeswoman Helen Gao said, "We are committed to continuing to work collaboratively with local Community Choice Aggregation programs to support their successful launch in 2021 and ensure that our mutual customers receive excellent customer service."
San Diego Community Power's case before the CPUC was joined by the California Community Choice Association, a trade group advocating for CCAs, and the Clean Energy Alliance — the North County-based CCA representing Del Mar, Solana Beach and Carlsbad that is scheduled to launch this summer.
SDCP will begin its rollout this year, folding in about 71,000 municipal, commercial and industrial accounts. The bulk of its roughly 700,000 residential accounts is expected to come in January 2022.
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.
Washington County solar farm incentives aim to steer projects to industrial sites with tax breaks, underground grid connections, decommissioning bonds, and wildlife corridors, balancing zoning, historic preservation, and Maryland renewable energy mandates.
Key Points
Policies steer solar to industrial sites with tax breaks, buried lines, and bonds, aligning with zoning and state goals.
✅ Tax breaks to favor rooftops and parking canopies
✅ Bury new grid lines to shift projects to industrial parks
✅ Require decommissioning bonds and wildlife corridors
Incentives for establishing solar farms at industrial spaces instead of on prime farmland are among the ideas the Washington County Planning Commission is recommending for the county to update its policies regarding solar farms.
Potential incentives would include tax breaks on solar equipment and requiring developers to put power-grid connections and line extensions underground, a move tied to grid upgrade cost debates in other regions, Planning Commission members said during a Monday meeting.
The tax break could make it more attractive for a developer to put a solar farm on a roof or over a parking lot, similar to California's building-solar requirement policies that favor rooftop generation, which could cost more than putting it on farmland, said Commission member Dave Kline, who works for FirstEnergy.
Requiring a company to bury new transmission lines could steer them to industrial or business parks where, theoretically, transmission lines are more readily available, Kline said Wednesday in a phone interview.
Chairman Clint Wiley suggested talking to industrial property owners to create a list of industrial sites that make sense for a solar site, which could generate extra income for the property owner.
Commission members also talked about requiring a wildlife corridor. Anne Arundel County requires such a corridor if a solar site is over 15 acres, according to Jill Baker, deputy director of planning and zoning. The solar site is broken into sections so animals such as deer can get through, she said.
However, that means the solar farm would take up more agricultural land, Commission member Jeremiah Weddle said. Weddle, a farmer, has repeatedly voiced concerns about solar farms using prime farmland.
County zoning law already states solar farms are prohibited in Rural Legacy Areas, Priority Preservation Areas, and within Antietam Overlay zones that preserve the Antietam National Battlefield viewshed. They also cannot be built on land with permanent preservation easements, Baker said.
However, a big reason county officials are looking to strengthen county policies for solar generating systems, or solar farms, is a recent court decision that ruled the Maryland Public Service Commission can preempt county zoning law when it comes to large solar farms.
County zoning law defines a solar energy generating system as a solar facility, with multiple solar arrays, tied into the power grid and whose primary purpose is to generate power to distribute and/or sell into the public utility grid rather than consuming that power on site.
The Maryland Court of Appeals ruled in July that the Public Service Commission can preempt local zoning regarding solar farms larger than 2 megawatts. But the ruling also stated local government is a "significant participant in the process" and the state commission must give "due consideration" to local zoning laws.
County officials are looking at recommendations for solar farms, whether they are over 2 megawatts or not.
Solar farms are a popular issue statewide, especially with Maryland solar subscriptions expanding, and were discussed at a recent Maryland Association of Counties meeting for planners, Planning and Zoning Director Stephen Goodrich said.
The thinking is the best way for counties to express their opinions about a solar project is to participate in the state commission's local public hearings, where issues like how solar owners are paid often arise, Goodrich said. Another popular idea is for the county to continue to follow its process, which requires a public hearing for a special exception to establish a solar farm. That will help the county form an opinion, on individual cases, to offer the state commission, he said.
Recommendations discussed by the Planning Commission include:
A break on personal property taxes, which is on equipment, including affordable battery storage that can firm output, to steer developers away from areas where the county doesn't want solar farms. The Board of County Commissioners have been split on tax-break agreements for solar farms, with a majority recently granting a few.
Protecting valuable historic sites.
Requiring a decommissioning bond for removing the equipment at the end of the solar farm's life. The bond is protection in case the company goes bankrupt. The county commissioners have been making such a bond a requirement when granting recent tax breaks.
Looking at allowing solar farms in stormwater-management areas.
Other counties, particularly in Western Maryland and on the Eastern Shore, are having issues with solar farms even as research to improve solar and wind advances, because land is cheaper and there are wide-open spaces, Goodrich said.
Many solar projects are being developed or proposed because state lawmakers passed legislation requiring 50% of electricity produced in the state to come from renewable sources by 2030, and a federal plan to expand solar is also shaping expectations. Of that 50%, 14.5% is to come from solar energy.
In Maryland, the average number of homes that can be powered by 1 megawatt of solar energy is about 110, according to the Solar Energy Industries Association's website.
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