As controversial and contentious as the recently passed deficit reduction package proved to be, Gov. Martin O'Malley and members of the General Assembly must now confront an equally difficult and quarrelsome issue: how to better regulate the state's electric utilities. Like the budget deficit, it's a complex and long-standing problem that's likely to require some painful choices.
While it's clear that Maryland's 1999 deregulation law was deeply flawed, and while the recent transition to market prices was more painful than it needed to be, Baltimore's relatively high electricity rates are only part of the problem. Reliability is just as important an issue. If not addressed, Baltimore-area residents could face the prospect of blackouts or brownouts on hot summer days as early as 2011.
The issues of price and reliability are closely related and stem from a dysfunctional market for power. As a net importer of electricity, the Baltimore-Washington area has limited options - put in more power lines, build more (or expand existing) power plants, invest in conservation measures, or pursue some combination of the three.
Two major new transmission lines have been approved by PJM Interconnection, the organization that coordinates wholesale electricity supplies for the region. They could help, but neither is likely to be completed in three years, nor would they fully solve the problem.
Conservation and alternative energy sources could also prove helpful, but they, too, have their limits. It's all very well to buy energy-saving appliances, but Maryland's power capacity shortfall - potentially 1,500 megawatts (roughly the equivalent of Constellation's Brandon Shores plant) in five years - is bigger then that.
Adding sufficient capacity would certainly solve the problem, but whether Constellation Energy and other generators in the region are willing to make the investment remains to be seen. The catch is that the lack of capacity and congestion on the grid allow generators to charge more, a strong disincentive to invest in risky infrastructure.
More will be known when PJM conducts auctions next month and in May to determine where the grid's power will likely come from in 2011 and 2012, but Maryland needs to develop a sound regulatory strategy. It could, for instance, be advantageous to require Baltimore Gas and Electric to lock into long-term contracts as an incentive for companies to invest more in new generation.
Members of the Public Service Commission are scheduled to begin briefing lawmakers on some of those options tomorrow. The grim reality is that the high prices BGE customers pay today aren't going away; that's the nature of the marketplace. But things could get a lot worse in the not-too-distant future and it's up to the PSC, as well as Governor O'Malley and the General Assembly, to do a better job of regulating the electric system than those who came before them.
California Wildfire Smoke Impact on Solar reduces photovoltaic output, as particulate pollution, soot, and haze dim sunlight and foul panels, cutting utility-scale generation and grid reliability across CAISO during peak demand and heatwaves.
Key Points
How smoke and soot cut solar irradiance and foul panels, slashing PV generation and straining CAISO grid operations.
✅ CAISO reported ~30% drop versus July during peak smoke.
✅ Longer fire seasons threaten solar reliability and capacity planning.
Smoke from California’s unprecedented wildfires was so bad that it cut a significant chunk of solar power production in the state, even as U.S. solar generation rose in 2022 nationwide. Solar power generation dropped off by nearly a third in early September as wildfires darkened the skies with smoke, according to the US Energy Information Administration.
Those fires create thick smoke, laden with particles that block sunlight both when they’re in the air and when they settle onto solar panels. In the first two weeks of September, soot and smoke caused solar-powered electricity generation to fall 30 percent compared to the July average, according to the California Independent System Operator (CAISO), which oversees nearly all utility-scale solar energy in California, where wind and solar curtailments have been rising amid grid constraints. It was a 13.4 percent decrease from the same period last year, even though solar capacity in the state has grown about 5 percent since September 2019.
California depends on solar installations for nearly 20 percent of its electricity generation, and has more solar capacity than the next five US states trailing it combined as it works to manage its solar boom sustainably. It will need even more renewable power to meet its goal of 100 percent clean electricity generation by 2045, building on a recent near-100% renewable milestone that underscored the transition. The state’s emphasis on solar power is part of its long-term efforts to avoid more devastating effects of climate change. But in the short term, California’s renewables are already grappling with rising temperatures.
Two records were smashed early this September that contributed to the loss of solar power. California surpassed 2 million acres burned in a single fire season for the first time (1.7 million more acres have burned since then). And on September 15th, small particle pollution reached the highest levels recorded since 2000, according to the California Air Resources Board. Winds that stoked the flames also drove pollution from the largest fires in Northern California to Southern California, where there are more solar farms.
Smaller residential and commercial solar systems were affected, too, and solar panels during grid blackouts typically shut off for safety, although smoke was the primary issue here. “A lot of my systems were producing zero power,” Steve Pariani, founder of the solar installation company Solar Pro Energy Systems, told the San Mateo Daily Journal in September.
As the planet heats up, California’s fire seasons have grown longer, and blazes are tearing through more land than ever before, while grid operators are also seeing rising curtailments as they integrate more renewables. For both utilities and smaller solar efforts, wildfire smoke will continue to darken solar energy’s otherwise bright future, even as it becomes the No. 3 renewable source in the U.S. by generation.
Electrically Smart Roads integrate solar road surfaces, inductive charging, IoT sensors, AI analytics, and V2X to power lighting, deicing, and monitoring, reducing grid dependence while enabling dynamic EV charging and real-time traffic management.
Key Points
Electrically smart roads generate power, sense conditions, and charge EVs using solar, IoT, AI, and dynamic infrastructure.
✅ Solar surfaces, verges, and gantries generate on-site electricity
✅ Inductive lanes enable dynamic EV charging at highway speeds
✅ Embedded IoT sensors and AI deliver real-time traffic insights
As more and more capabilities are added to roads instead of simply covering a country with extra roads, they are starting to make their own electricity, notably as solar road surface but then with added silent wind turbines, photovoltaic verges and barriers and more.
That toll gate, street light and traffic monitoring system all need electricity. Later, roads that deice and charge vehicles at speed will need huge amounts of electricity. For now, electricity for road systems is provided by very expensive infrastructure to the grid, and grid flexibility for EVs remains a concern, except for a few solar/ wind street lights in China and Korea for example. However, as more and more capabilities are added to roads instead of simply covering a country with extra roads, they are starting to make their own electricity, notably as solar road surface but then with added silent wind turbines, photovoltaic verges and barriers and more. There is also highly speculative work in the USA and UK on garnering power from road surface movement using piezoelectrics and electrodynamics and even its heat.
#google#
China plans to create an intelligent transport system by 2030. The country hopes to build smart roads that will not only be able to charge electric cars as they drive but also monitor temperature, traffic flow and weight load using artificial intelligence. Indeed, like France, the Netherlands and the USA, where U.S. EV charging capacity is under scrutiny, it already has trials of extended lengths of solar road which cost no more than regular roads. In an alternative approach, vehicles go under tunnels of solar panels that also support lighting, light-emitting signage and monitoring equipment using the electricity made where it is needed. See the IDTechEx Research report, Electrically Smart Roads 2018-2028 for more.
Raghu Das, CEO of IDTechEx says, "The spiral vertical axis wind turbines VAWT in Asia rarely rotate because they are too low but much higher versions are planned on large UK roadside vehicle charging centres that should work well. H shaped VAWT is also gaining traction - much slower and quieter than the propeller shape which vibrates and keeps you awake at night in an urban area.
The price gap between the ubiquitous polycrystalline silicon solar cell and the much more efficient single crystal silicon is narrowing. That means that road furniture such as bus shelters and smart gantries will likely go for more solar rather than adding wind power in many cases, a shift mirrored by connected solar tech in homes, because wind power needs a lot of maintenance and its price is not dropping as rapidly."
The IDTechEx Research report, Off Grid Electric Vehicle Charging: Zero Emission 2018-2028 analyses that aspect, while vehicle-to-grid strategies may complement grid resources. The prototype of a smart road is already in place on an expressway outside of Jinan, providing better traffic updates as well as more accurate mapping. Verizon's IoT division has launched a project around intelligent asphalt, which it thinks has the potential to significantly reduce fossil fuel emissions and save time by reducing up to 44% of traffic backups. It has partnered with Sacramento, California, to test this theory.
"By embedding sensors into the pavement as well as installing cameras on traffic lights, we will be able to study and analyze the flow of traffic. Then, we will take all of that data and use it to optimize the timing of lights so that traffic flows easier and travel times are shorter," explains Sean Harrington, vice president of Verizon Smart Communities.
Colorado's Department of Transportation has recently announced its intention to be the first state to pilot smart roads by striking a five-year deal with a smart road company to test the technology. Like planned auto-deicing roads elsewhere, the aim of this project is, first and foremost, to save lives. The technology will detect when a car suddenly leaves a road and send emergency assistance to the area. The IDTechEx Research report Electrically Smart Roads 2018-2028 describes how others work on real time structural monitoring of roads and embedded interactive lighting and road surface signage.
"Smart pavement can make that determination and send that information directly into a vehicle," Peter Kozinski, director of CDOT's RoadX division, tells the Denver Post. "Data is the new asphalt of transportation." Sensors, processors and other technology are embedded in the Colorado road to extend capability beyond accidents and reach into better road maintenance. Fast adoption relies on the ability to rapidly install sensor-laden pavement or lay concrete slabs. Attention therefore turns to fast adaptation of existing roads. Indeed, even for the heavy coil arrays used for dynamic vehicle charging, even as state power grids face new challenges, in Israel there are machines that can retrofit into the road surface at a remarkable two kilometres of cut and insert in a day.
"It's hard to imagine that these things are inexpensive, with all the electronics in them," Charles Schwartz, a professor of civil and environmental engineering at the University of Maryland, tells the Denver Post concerning the vehicle sensing project, "but CDOT is a fairly sophisticated agency, and this is an interesting pilot project. We can learn a lot, even if the test is only partially successful."
Drax Biomass Conversion accelerates renewable energy by replacing coal with wood pellets, sustainable forestry feedstock, and piloting carbon capture and storage, supporting the UK grid, emissions cuts, and a net-zero pathway.
Key Points
Drax Biomass Conversion is Drax's shift from coal to biomass with CCS pilots to cut emissions and aid UK's net-zero.
✅ Coal units converted to biomass wood pellets
✅ Sourced from sustainable forestry residues
✅ CCS pilots target lifecycle emissions cuts
A power station that used to be the biggest polluter in western Europe has made a near-complete switch to renewable energy, mirroring broader shifts as Denmark's largest energy company plans to end coal by 2023.
The Drax Power Station in Yorkshire, England, used to spew out millions of tons of carbon dioxide a year by burning coal. But over the past eight years, it has overhauled its operations by converting four of its six coal-fired units to biomass. The plant's owners say it now generates 15% of the country's renewable power, as Britain recently went a full week without coal power for the first time.
The change means that just 6% of the utility's power now comes from coal, as the wider UK coal share hits record lows across the national electricity system. The ultimate goal is to stop using coal altogether.
"We've probably reduced our emissions more than any other utility in the world by transforming the way we generate power," Will Gardner, CEO of the Drax Group, told CNN Business.
Subsidies have helped finance the switch to biomass, which consists of plant and agricultural matter and is viewed as a promising substitute for coal, and utilities such as Nova Scotia Power are also increasing biomass use. Last year, Drax received £789 million ($1 billion) in government support.
Is biomass good for the environment?
While scientists disagree over the extent to which biomass as a fuel is environmentally friendly, and some environmentalists urge reducing biomass use amid concerns about lifecycle emissions, Drax highlights that its supplies come from from sustainably managed and growing forests.
Most of the biomass used by Drax consists of low-grade wood, sawmill residue and trees with little commercial value from the United States. The material is compressed into sawdust pellets.
Gardner says that by purchasing bits of wood not used for construction or furniture, Drax makes it more financially viable for forests to be replanted. And planting new trees helps offset biomass emissions.
Forests "absorb carbon as they're growing, once they reach maturity, they stop absorbing carbon," said Raphael Slade, a senior research fellow at Imperial College London.
But John Sterman, a professor at MIT's Sloan School of Management, says that in the short term burning wood pellets adds more carbon to the atmosphere than burning coal.
That carbon can be absorbed by new trees, but Sterman says the process can take decades.
"If you're looking at five years, [biomass is] not very good ... If you're looking at a century-long time scale, which is the sort of time scale that many foresters plan, then [biomass] can be a lot more beneficial," says Slade.
Carbon capture
Enter carbon capture and storage technology, which seeks to prevent CO2 emissions from entering the atmosphere and has been touted as a possible solution to the climate crisis.
Drax, for example, is developing a system to capture the carbon it produces from burning biomass. But that could be 10 years away.
The Coal King is racing to avoid bankruptcy
The power station is currently capturing just 1 metric ton of CO2 emissions per day. Gardner says it hopes to increase this to 10,000 metric tons per day by the mid to late 2020s.
"The technology works but scaling it up and rolling it out, and financing it, are going to be significant challenges," says Slade.
The Intergovernmental Panel on Climate Change shares this view. The group said in a 2018 report that while the potential for CO2 capture and storage was considerable, its importance in the fight against climate change would depend on financial incentives for deployment, and whether the risks of storage could be successfully managed. These include a potential CO2 pipeline break.
In the United Kingdom, the government believes that carbon capture and storage will be crucial to reaching its goal of achieving net-zero greenhouse gas emissions by 2050, even as low-carbon generation stalled in 2019 according to industry analysis.
It has committed to consulting on a market-based industrial carbon capture framework and in June awarded £26 million ($33 million) in funding for nine carbon capture, usage and storage projects, amid record coal-free generation on the British grid.
Cold-Climate Heat Pumps deliver efficient heating and cooling for Northern B.C. Net Zero Ready homes, with air-source Mitsubishi H2i systems, triple-pane windows, blower door ACH 0.8, BC Hydro rebates, and CleanBC incentives.
Key Points
Electric air-source systems that heat and cool in subzero climates, cutting emissions and lowering energy costs.
✅ Net Zero Ready, Step Code 5, ACH 0.8 airtightness
✅ Operate efficiently to about -28 C with backup heat
✅ Eligible for BC Hydro and CleanBC rebates
Heat pump provides heating, cooling in northern B.C. home It's a tradition at Vanderhoof-based Northern Homecraft that, on the day of the blower door test for a just-completed home, everyone who worked on the build gathers to watch it happen. And in the spring of 2021, on a dazzling piece of land overlooking the mouth of the Stuart River near Fort St. James, that day was a cause for celebration.
A new 3,400-square foot home subjected to the blower door test – a diagnostic tool to determine how much air is entering or escaping from a home – was rated as having just .8 air changes per hour (ACH). That helps make it a Net Zero Ready home, and BC Energy Code Step 5 compliant. That means it would take about a third of the amount of energy to heat the home compared to a typical similar-sized home in B.C. today.
From an energy-efficiency perspective, this is a home whose evident beauty is anything but skin deep.
"The home has lot of square footage of finished living space, and it also has a lot of glazing," says Northern Homecraft owner Shay Bulmer, referring to the home's large windows. "We had a lot of window space to deal with, as well as large vaulted open areas where you can only achieve so much additional insulation. There were a few things that the home had going against it as far as performance goes. There were challenges in keeping it comfortable year-round."
Well-insulated home ideal for heat pump option Most homes in colder areas of B.C. lean on gas-fueled heating systems to deal with the often long, chilly winters. But with the arrival of cold climate heat pumps capable of providing heat efficiently when temperatures dip as low as -30°C, there's now a clean option for those homes, and using more electricity for heat is gaining support in the North as well.
Heat pumps are an increasingly popular option, both for new and existing homes, because they avoid carbon emissions associated with fossil use while also offering summer cooling, even as record-high electricity demand in Yukon underscores the need for efficient systems.
The Fort St. James home, which was built with premium insulation, airtightness and energy efficiency in mind, made the decision to opt for a heat pump even easier. Still, the heat pump option took the home's owners Dexter and Cheryl Hodder by surprise. While their focus was on designing a home that took full advantage of views down to the river, the couple was under the distinct impression that heat pumps couldn't cut it in the chilly north.
"I wasn't really considering a heat pump, which I thought was only a good solution in a moderate climate," says Dexter, who as director of research and education for the John Prince Research Forest, studies wildlife and forestry interactions in north central B.C. "The specs on the heat pump indicate it would work down to -28°C, and I was skeptical of that. But it worked exactly to spec. It almost seems ridiculous to generate heat from outside air at those low temperatures, but it does."
Getting it right with support and rebates Northern Homecraft took advantage of BC Hydro's Mechanical System Design Pilot program to ensure proper heat pump system design, installation, and verification for the home were applied, and with BC Hydro's first call for power in 15 years driven by electrification, the team prioritized efficient load management.
Based on the home's specific location, size, and performance targets, they installed a ducted Mitsubishi H2I air-source heat pump system. Windows are triple pane, double coated, and a central feature of the home, while insulation specifications were R-40 deep frame insulation in the exterior walls, R-80 insulation in the attic, and R-40 insulation in the vaulted ceilings.
The combination of the year-round benefits of heat pumps, their role in reducing fossil fuel emissions, and the availability of rebates, is making the systems increasingly attractive in B.C., especially as two new BC generating stations were recently commissioned to expand clean supply.
BC Hydro offers home renovation rebates of up to $10,000 for energy-efficient upgrades to existing homes. Rebates are available for windows and doors, insulation, heat pumps, and heat pump hot water heaters. In partnership with CleanBC, rebates of up to $11,000 are also available – when combined with the federal Greener Homes program – for those switching from fossil fuel heating to an electric heat pump.
'Heat dome' pushes summer highs to 40°C Cooling wasn't really a consideration for Dexter and Cheryl when they were living in a smaller bungalow shaded by trees. But they knew that with the big windows, vaulted ceiling in the living room, and an upstairs bedroom in the new home, there may come a time when they needed air conditioning.
That day arrived shortly after the home was built, as the infamous "heat dome" settled on B.C. and drove temperatures at Fort St. James to a dizzying 40°C.
"It was disgustingly hot, and I don't care if I never see that again here," says Hodder, with a laugh. "But the heat pump maintained the house really nicely throughout, at about 22 degrees. The whole house stayed cool. We just had to close the door to the upper bedroom so it wasn't really heating up during the day."
Hodder says he had to work with the heat pump manufacturer Mitsubishi a couple times over that first year to fix a few issues with the system's controls. But he's confident that the building's tight and well-insulated envelope, and the heat pump's backup electric heat that kicks in when temperatures dip below -28°C, will make it the system-for-all-seasons it was designed to be.
Even with the use of supplemental electric heating during the record chill of December-January, the home's energy costs weren't much higher than the mid-winter energy bills they used to pay in the couple's smaller bungalow that relied on a combination of gas-fired in-floor heating and electric baseboards, as gas-for-electricity swaps are being explored elsewhere.
Fort St. James is a former fur trading post located northwest of Prince George and a short drive north of Vanderhoof. Winters are cold and snowy, with average daily low temperatures in December and January of around -14°C.
"During the summer and into the fall, we were paying well less than $100 a month," says Hodder, looking back at electricity bills over the first year in the home. "And that's everything. We're only electric here, and we also had both of us working from home all last year."
Word of mouth making heat pumps popular in Fort St. James While the size of the home presented new challenges for the builders, it's one of five Net Zero Ready or Net Zero homes – all equipped with some form of heat pump – that Northern Homecraft has built in Fort St. James, even as debates about going nuclear for electricity continue in B.C.
The smallest of the homes is a two-bedroom, one-bathroom home that's just under 900 square feet. Northern Homecraft may be based in Vanderhoof, but it's the much smaller town of Fort St. James where they're making their mark with super-efficient homes. Net Zero Ready homes are up to 80% more efficient than the standard building code, and become Net Zero once renewable energy generation – usually in the form of photovoltaic solar – is installed, and programs like switching 5,000 homes to geothermal show the broader momentum for clean heating.
"We were pretty proud that the first home we built in Fort St. James was the first single family Net Zero Ready home built in B.C.," says Northern Homecraft's Bulmer. "And I think it's kind of caught on in a smaller community where everyone talks to everyone."
US Renewable Power Outlook 2030 projects surging capacity, solar PV and wind growth, grid modernization, and favorable tax credits, detailing market trends, CAGR, transmission expansion, and policy drivers shaping clean energy generation and consumption.
Key Points
A forecast of US power capacity, generation, and consumption, highlighting solar, wind, tax credits, and grid modernization.
✅ Targets 48.4% renewable capacity share by 2030
✅ Strong growth in solar PV and onshore wind installations
✅ Investment and tax credits drive grid and transmission upgrades
GlobalData’s latest report, ‘United States Power Market Outlook to 2030, Update 2021 – Market Trends, Regulations, and Competitive Landscape’ discusses the power market structure of the United States and provides historical and forecast numbers for capacity, generation and consumption up to 2030. Detailed analysis of the country’s power market regulatory structure, competitive landscape and a list of major power plants are provided. The report also gives a snapshot of the power sector in the country on broad parameters of macroeconomics, supply security, generation infrastructure, transmission and distribution infrastructure, about a quarter of U.S. electricity from renewables in recent years, electricity import and export scenario, degree of competition, regulatory scenario, and future potential. An analysis of the deals in the country’s power sector is also included in the report.
Renewable power held a 19% share of the US’s total power capacity in 2020, and in that year renewables became the second-most prevalent source in the U.S. electricity mix by generation; this share is expected to increase significantly to 48.4% by 2030. Favourable policies introduced by the US Government will continue to drive the country’s renewable sector, particularly solar photovoltaics (PV) and wind power, with wind now the most-used renewable source in the U.S. generation mix. Installed renewable capacity* increased from 16.5GW in 2000 to 239.2GW in 2020, growing at a compound annual growth rate (CAGR) of 14.3%. By 2030, the cumulative renewable capacity is expected to rise to 884.6GW, growing at a CAGR of 14% from 2020 to 2030. Despite increase in prices of renewable equipment, such as solar modules, in 2021, the US renewable sector will show strong growth during the 2021 to 2030 period as this increase in equipment prices are short term due to supply chain disruptions caused by the Covid-19 pandemic.
The expansion of renewable power capacity during the 2000 to 2020 period has been possible due to the introduction of federal schemes, such as Production Tax Credits, Investment Tax Credits and Manufacturing Tax Credits. These have massively aided renewable installations by bringing down the cost of renewable power generation and making it at par with power generated from conventional sources. Over the last few years, the cost of solar PV and wind power installations has declined sharply, and by 2023 wind, solar, and batteries made up most of the utility-scale pipeline across the US, highlighting investor confidence. Since 2010, the cost of utility-scale solar PV projects decreased by around 82% while onshore wind installations decreased by around 39%. This has supported the rapid expansion of the renewable market. However, the price of solar equipment has risen due to an increase in raw material prices and supply shortages. This may slightly delay the financing of some solar projects that are already in the pipeline.
The US will continue to add significant renewable capacity additions during the forecast period as industry outlooks point to record solar and storage installations over the coming years, to meet its target of reaching 80% clean energy by 2030. In November 2021, President Biden signed a $1tr Infrastructure Bill, within which $73bn is designated to renewables. This includes not just renewable capacity building, but also strengthening the country’s power grid and laying new high voltage transmission lines, both of which will be key to driving solar and wind power capacity additions as wind power surges in the U.S. electricity mix nationwide.
The US was one of the worst hit countries in the world due to the Covid-19 pandemic in 2020. With respect to the power sector, the electricity consumption in the country declined by 2.5% in 2020 as compared to 2019, even as renewable electricity surpassed coal in 2022 in the generation mix, highlighting continued structural change. Power plants that were under construction faced delays due to unavailability of components due to supply chain disruptions and unavailability of labour due to travel restrictions.
According to the US Energy Information Administration, 61 power projects, having a total capacity of 2.4GWm which were under construction during March and April 2020 were delayed because of the Covid-19 pandemic. Among renewable power technologies, solar PV and wind power projects were the most badly affected due to the pandemic.
In March and April 2020, 53 solar PV projects, having a total capacity of 1.3GW, and wind power projects, having a total capacity of 1.2GW, were delayed due to the Covid-19 pandemic. Moreover, several states suspended renewable energy auctions due to the pandemic.
For instance, New York State Energy Research and Development Authority (NYSERDA) had issued a new offshore wind solicitation for 1GW and up to 2.5GW in April 2020, but this was suspended due to the Covid-19 pandemic. In July 2020, the authority relaunched the tender for 2.5GW of offshore wind capacity, with a submission deadline in October 2020.
To ease the financial burden on consumers during the pandemic, more than 1,000 utilities in the country announced disconnection moratoria and implemented flexible payment plans. Duke Energy, American Electric Power, Dominion Power and Southern California Edison were among the major utilities that voluntarily suspended disconnections.
Boeing 787 More-Electric Architecture replaces pneumatics with bleedless pressurization, VFSG starter-generators, electric brakes, and heated wing anti-ice, leveraging APU, RAT, batteries, and airport ground power for efficient, redundant electrical power distribution.
Key Points
An integrated, bleedless electrical system powering start, pressurization, brakes, and anti-ice via VFSGs, APU and RAT.
✅ VFSGs start engines, then generate 235Vac variable-frequency power
✅ Bleedless pressurization, electric anti-ice improve fuel efficiency
✅ Electric brakes cut hydraulic weight and simplify maintenance
The 787 Dreamliner is different to most commercial aircraft flying the skies today. On the surface it may seem pretty similar to the likes of the 777 and A350, but get under the skin and it’s a whole different aircraft.
When Boeing designed the 787, in order to make it as fuel efficient as possible, it had to completely shake up the way some of the normal aircraft systems operated. Traditionally, systems such as the pressurization, engine start and wing anti-ice were powered by pneumatics. The wheel brakes were powered by the hydraulics. These essential systems required a lot of physical architecture and with that comes weight and maintenance. This got engineers thinking.
What if the brakes didn’t need the hydraulics? What if the engines could be started without the pneumatic system? What if the pressurisation system didn’t need bleed air from the engines? Imagine if all these systems could be powered electrically… so that’s what they did.
Power sources
The 787 uses a lot of electricity. Therefore, to keep up with the demand, it has a number of sources of power, much as grid operators track supply on the GB energy dashboard to balance loads. Depending on whether the aircraft is on the ground with its engines off or in the air with both engines running, different combinations of the power sources are used.
Engine starter/generators
The main source of power comes from four 235Vac variable frequency engine starter/generators (VFSGs). There are two of these in each engine. These function as electrically powered starter motors for the engine start, and once the engine is running, then act as engine driven generators.
The generators in the left engine are designated as L1 and L2, the two in the right engine are R1 and R2. They are connected to their respective engine gearbox to generate electrical power directly proportional to the engine speed. With the engines running, the generators provide electrical power to all the aircraft systems.
APU starter/generators
In the tail of most commercial aircraft sits a small engine, the Auxiliary Power Unit (APU). While this does not provide any power for aircraft propulsion, it does provide electrics for when the engines are not running.
The APU of the 787 has the same generators as each of the engines — two 235Vac VFSGs, designated L and R. They act as starter motors to get the APU going and once running, then act as generators. The power generated is once again directly proportional to the APU speed.
The APU not only provides power to the aircraft on the ground when the engines are switched off, but it can also provide power in flight should there be a problem with one of the engine generators.
Battery power
The aircraft has one main battery and one APU battery. The latter is quite basic, providing power to start the APU and for some of the external aircraft lighting.
The main battery is there to power the aircraft up when everything has been switched off and also in cases of extreme electrical failure in flight, and in the grid context, alternatives such as gravity power storage are being explored for long-duration resilience. It provides power to start the APU, acts as a back-up for the brakes and also feeds the captain’s flight instruments until the Ram Air Turbine deploys.
Ram air turbine (RAT) generator
When you need this, you’re really not having a great day. The RAT is a small propeller which automatically drops out of the underside of the aircraft in the event of a double engine failure (or when all three hydraulics system pressures are low). It can also be deployed manually by pressing a switch in the flight deck.
Once deployed into the airflow, the RAT spins up and turns the RAT generator. This provides enough electrical power to operate the captain’s flight instruments and other essentials items for communication, navigation and flight controls.
External power
Using the APU on the ground for electrics is fine, but they do tend to be quite noisy. Not great for airports wishing to keep their noise footprint down. To enable aircraft to be powered without the APU, most big airports will have a ground power system drawing from national grids, including output from facilities such as Barakah Unit 1 as part of the mix. Large cables from the airport power supply connect 115Vac to the aircraft and allow pilots to shut down the APU. This not only keeps the noise down but also saves on the fuel which the APU would use.
The 787 has three external power inputs — two at the front and one at the rear. The forward system is used to power systems required for ground operations such as lighting, cargo door operation and some cabin systems. If only one forward power source is connected, only very limited functions will be available.
The aft external power is only used when the ground power is required for engine start.
Circuit breakers
Most flight decks you visit will have the back wall covered in circuit breakers — CBs. If there is a problem with a system, the circuit breaker may “pop” to preserve the aircraft electrical system. If a particular system is not working, part of the engineers procedure may require them to pull and “collar” a CB — placing a small ring around the CB to stop it from being pushed back in. However, on the 787 there are no physical circuit breakers. You’ve guessed it, they’re electric.
Within the Multi Function Display screen is the Circuit Breaker Indication and Control (CBIC). From here, engineers and pilots are able to access all the “CBs” which would normally be on the back wall of the flight deck. If an operational procedure requires it, engineers are able to electrically pull and collar a CB giving the same result as a conventional CB.
Not only does this mean that the there are no physical CBs which may need replacing, it also creates space behind the flight deck which can be utilised for the galley area and cabin.
A normal flight
While it’s useful to have all these systems, they are never all used at the same time, and, as the power sector’s COVID-19 mitigation strategies showed, resilience planning matters across operations. Depending on the stage of the flight, different power sources will be used, sometimes in conjunction with others, to supply the required power.
On the ground
When we arrive at the aircraft, more often than not the aircraft is plugged into the external power with the APU off. Electricity is the blood of the 787 and it doesn’t like to be without a good supply constantly pumping through its system, and, as seen in NYC electric rhythms during COVID-19, demand patterns can shift quickly. Ground staff will connect two forward external power sources, as this enables us to operate the maximum number of systems as we prepare the aircraft for departure.
Whilst connected to the external source, there is not enough power to run the air conditioning system. As a result, whilst the APU is off, air conditioning is provided by Preconditioned Air (PCA) units on the ground. These connect to the aircraft by a pipe and pump cool air into the cabin to keep the temperature at a comfortable level.
APU start
As we near departure time, we need to start making some changes to the configuration of the electrical system. Before we can push back , the external power needs to be disconnected — the airports don’t take too kindly to us taking their cables with us — and since that supply ultimately comes from the grid, projects like the Bruce Power upgrade increase available capacity during peaks, but we need to generate our own power before we start the engines so to do this, we use the APU.
The APU, like any engine, takes a little time to start up, around 90 seconds or so. If you remember from before, the external power only supplies 115Vac whereas the two VFSGs in the APU each provide 235Vac. As a result, as soon as the APU is running, it automatically takes over the running of the electrical systems. The ground staff are then clear to disconnect the ground power.
If you read my article on how the 787 is pressurised, you’ll know that it’s powered by the electrical system. As soon as the APU is supplying the electricity, there is enough power to run the aircraft air conditioning. The PCA can then be removed.
Engine start
Once all doors and hatches are closed, external cables and pipes have been removed and the APU is running, we’re ready to push back from the gate and start our engines. Both engines are normally started at the same time, unless the outside air temperature is below 5°C.
On other aircraft types, the engines require high pressure air from the APU to turn the starter in the engine. This requires a lot of power from the APU and is also quite noisy. On the 787, the engine start is entirely electrical.
Power is drawn from the APU and feeds the VFSGs in the engines. If you remember from earlier, these fist act as starter motors. The starter motor starts the turn the turbines in the middle of the engine. These in turn start to turn the forward stages of the engine. Once there is enough airflow through the engine, and the fuel is igniting, there is enough energy to continue running itself.
After start
Once the engine is running, the VFSGs stop acting as starter motors and revert to acting as generators. As these generators are the preferred power source, they automatically take over the running of the electrical systems from the APU, which can then be switched off. The aircraft is now in the desired configuration for flight, with the 4 VFSGs in both engines providing all the power the aircraft needs.
As the aircraft moves away towards the runway, another electrically powered system is used — the brakes. On other aircraft types, the brakes are powered by the hydraulics system. This requires extra pipe work and the associated weight that goes with that. Hydraulically powered brake units can also be time consuming to replace.
By having electric brakes, the 787 is able to reduce the weight of the hydraulics system and it also makes it easier to change brake units. “Plug in and play” brakes are far quicker to change, keeping maintenance costs down and reducing flight delays.
In-flight
Another system which is powered electrically on the 787 is the anti-ice system. As aircraft fly though clouds in cold temperatures, ice can build up along the leading edge of the wing. As this reduces the efficiency of the the wing, we need to get rid of this.
Other aircraft types use hot air from the engines to melt it. On the 787, we have electrically powered pads along the leading edge which heat up to melt the ice.
Not only does this keep more power in the engines, but it also reduces the drag created as the hot air leaves the structure of the wing. A double win for fuel savings.
Once on the ground at the destination, it’s time to start thinking about the electrical configuration again. As we make our way to the gate, we start the APU in preparation for the engine shut down. However, because the engine generators have a high priority than the APU generators, the APU does not automatically take over. Instead, an indication on the EICAS shows APU RUNNING, to inform us that the APU is ready to take the electrical load.
Shutdown
With the park brake set, it’s time to shut the engines down. A final check that the APU is indeed running is made before moving the engine control switches to shut off. Plunging the cabin into darkness isn’t a smooth move. As the engines are shut down, the APU automatically takes over the power supply for the aircraft. Once the ground staff have connected the external power, we then have the option to also shut down the APU.
However, before doing this, we consider the cabin environment. If there is no PCA available and it’s hot outside, without the APU the cabin temperature will rise pretty quickly. In situations like this we’ll wait until all the passengers are off the aircraft until we shut down the APU.
Once on external power, the full flight cycle is complete. The aircraft can now be cleaned and catered, ready for the next crew to take over.
Bottom line
Electricity is a fundamental part of operating the 787. Even when there are no passengers on board, some power is required to keep the systems running, ready for the arrival of the next crew. As we prepare the aircraft for departure and start the engines, various methods of powering the aircraft are used.
The aircraft has six electrical generators, of which only four are used in normal flights. Should one fail, there are back-ups available. Should these back-ups fail, there are back-ups for the back-ups in the form of the battery. Should this back-up fail, there is yet another layer of contingency in the form of the RAT. A highly unlikely event.
The 787 was built around improving efficiency and lowering carbon emissions whilst ensuring unrivalled levels safety, and, in the wider energy landscape, perspectives like nuclear beyond electricity highlight complementary paths to decarbonization — a mission it’s able to achieve on hundreds of flights every single day.
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