In its drive to go green, the technology industry has so far focused mainly on big targets like corporations and especially computer data centers, the power-hungry computing engine rooms of the Internet economy.
Next come the hundreds of millions of desktop and laptop personal computers in households worldwide.
Microsoft, the nonprofit Climate Savers Computing Initiative and a start-up called Verdiem are combining to put a spotlight on the energy-saving opportunity in PCs, and distributing a free software tool to consumers to help them do it.
The potential savings in both dollars and pollution is huge, analysts say, when the estimated one billion PCs in use globally are taken into account. The research firm Gartner estimates that 40 percent of all carbon dioxide emissions resulting from information technology and telecommunications are attributable to PCs. Data center computers account for 23 percent, and the rest is attributable to printers and telecommunications equipment.
“If you are going to tackle climate change and curb energy use, you have to deal with consumer devices like PCs,” said Andrew Fanara, a product development expert in the Environmental Protection Agency’s Energy Star program, which promotes energy-efficient products and practices.
For more than a decade, the federal Energy Star program has developed voluntary power-management standards for PCs, and suppliers like Intel and Microsoft have steadily improved the energy efficiency of their chips and software. But Mr. Fanara estimated that less than half of PCs met those standards, in part because more energy-efficient hardware adds slightly to production costs.
“There are large potential savings beyond what Energy Star can do,” he said.
The free software, called Edison, is a consumer version of the PC energy-saving software sold to corporate customers by Verdiem, which is financed by Kleiner Perkins Caufield & Byers, a leading venture capital firm and an aggressive investor in green technologies, and other venture investors.
Verdiem, based in Seattle, has 180 corporate and government customers, including Hewlett-Packard, which bundles VerdiemÂ’s Surveyor program on its desktop PCs sold to corporations. Though he will not disclose sales figures, the companyÂ’s chief executive, Kevin Klustner, says revenue should triple this year.
There are other free tools for calculating and managing PC power consumption, including the E.P.A.Â’s EZ Wizard, CO2 Saver and a Google energy-saving gadget. But Edison allows the user more flexibility, especially in making the settings as stringent as they want, analysts say.
If a user sets the software to put the machine in a “deep sleep” mode after a few minutes of not hitting a keystroke, the hard drive powers down and the PC sips just 5 percent of its normal energy consumption.
That kind of energy diet is far from standard practice in homes and offices. Half of all electricity consumed by a standard PC is wasted, according to environmental and industry studies.
Household electricity bills could also be trimmed by $20 to $95 a year for each PC, depending on local power costs and the kind of PCs in use, said Mr. Klustner. “What we’re trying to do is raise the visibility of the power consumption problem on the PC desktop and really bring power management to the masses,” he said.
The Climate Savers group, which includes major technology companies and environmental groups, has set a goal of reducing carbon dioxide emissions from computers by 54 million tons by 2010. That is the equivalent of the yearly pollution from 11 million cars. The goal includes data center computers and PCs, and about half of all PCs are consumer machines.
“This kind of energy-saving technology for consumers is a key ingredient in moving toward that goal,” said Rob Bernard, chief environmental strategist for Microsoft.
The companies said that the Edison software would be available to download on August 6 from the Web sites of Verdiem (verdiem.com), Microsoft (microsoft.com/environment), and Climate Savers (climatesaverscomputing.org).
India spot electricity prices surged on Q3 demand, lifting power tariffs in the spot market as discoms scrambled for supply; Sembcorp SGPL boosted PLF and short-term PPA realizations, benefiting from INR per kWh peaks.
Key Points
India spot electricity prices hit Q3 records amid demand spikes, lifting tariffs and aiding Sembcorp SGPL via PLF gains.
✅ Record 10.6 cents/kWh average; 15-minute peak 20.7 cents/kWh
✅ SGPL shifted output to short-term PPA at 7.3 cents/kWh
✅ PLF ramped above 90%, cutting core losses by 30-40%
Electricity prices in India, now the third-largest electricity producer globally, bolted to a record high of 10.6 cents/kWh (INR5.1/kWh) in Q3.
A jolt in Indian spot electricity prices could save Sembcorp Industries' Indian business from further losses, even though demand has occasionally slumped in recent years, UOB Kay Hian said.
The firm said spot electricity prices in India bolted to a record high of 10.6 cents/kWh (INR5.1/kWh) in Q3 and even hit a 15-minute peak of 20.7 cents/kWh (9.9/kWh). The spike was due to a power supply crunch on higher electricity demand from power distribution companies, alongside higher imported coal volumes as domestic supplies shrank.
As an effect, Sembcorp Industries' Sembcorp Gayatri Power Limited's (SGPL) losses of $26m in Q1 and $29m in Q2 could narrow down by as much as 30-40%.
On a net basis, SGPL will recognise a significantly higher electricity tariff in 3Q17. By tactically shutting down its Unit #3 for maintenance, Unit #4 effectively had its generation contracted out at the higher short-term PPA tariff of around 7.3 cents/kWh (Rs3.5/kWh).
SGPL also capitalised on the price spike in 3Q17 as it ramped up its plant load factor (PLF) to more than 90%.
“On the back of this, coupled with the effects of reduced finance costs, we expect SGPL’s 3Q17 quarterly core loss to shrink by 30-40% from previous quarters,” UOB Kay Hian said.
Whilst electricity prices have corrected to 7.1 cents/kWh (INR3.4/kWh), the firm said it could still remain elevated on structural factors, even as coal and electricity shortages ease nationwide.
Sembcorp Industries' India operations brought in a robust performance for Q3. PLF for Thermal Powertech Corporation India Limited (TPCIL) hit 91%, whilst it reached 73% for SGPL, echoing the broader trend of thermal PLF up across the sector.
Saudi Arabia Wind Power Market set to lead the Middle East, driven by Vision 2030 renewables goals, REPDO tenders, and PIF backing, adding 6.2GW wind capacity by 2028 alongside solar PV diversification.
Key Points
It is the emerging national segment leading Middle East wind growth, targeting 6.2GW by 2028 under Vision 2030 policies.
✅ Adds 6.2GW, 46% of regional wind capacity by 2028
✅ REPDO tenders and PIF funding underpin pipeline
✅ Targets: 16GW wind, 40GW solar under Vision 2030
Saudi Arabia will become a regional heavyweight in the Middle East's wind power market adding over 6GW in the next 10 years, according to new research by Wood Mackenzie Power & Renewables.
The report – 'Middle East Wind Power Market Outlook, 2019-2028’ – said developers will build 6.2GW of wind capacity in the country or 46% of the region’s total wind capacity additions between 2019 and 2028.
Wood Mackenzie Power & Renewables senior analyst Sohaib Malik said: “The integration of renewables in Vision 2030’s objectives underlines strong political commitment within Saudi Arabia.
“The level of Saudi ambition for wind and solar PV varies significantly, despite the cost parity between both technologies during the first round of tenders in 2018.”
Saudi Arabia has set a 16GW target for wind by 2030 and 40GW for solar, plans to solicit 60 GW of clean energy over the next decade, Wood Mackenzie added.
“Moving forward, the Renewable Energy Project Development Office will award 850MW of wind capacity in 2019, which is expected to be commissioned in 2021-2022, and increase the local content requirement in future tendering rounds,” Malik said.
However, Saudi Arabia will fall short of its current 2030 renewables target, despite growth projections and regional leadership, the report said.
Some 70% of the renewables capacity target is to be supported by the Public Investment Fund (PIF), the Saudi sovereign wealth fund, while the remaining capacity is to be awarded through REPDO.
“A central concern is the PIF’s lack of track record in the renewables sector and its limited in-house sectoral expertise,” said Malik
“REPDO, on the other hand, completed two renewables request for proposals after pre-developing the sites,” he said.
PIF is estimated to have $230bn of assets – targeted to reach $2 trillion under Vision 2030 – driven by investments in a variety of sectors ranging from electric vehicles to public infrastructure, Wood Mackenzie said.
“There is little doubt about the fund’s financial muscle, however, its past investment strategy focused on established firms in traditional industries,” Malik added.
“Aspirations to develop a value chain for wind and PV technologies locally is a different ball game and requires the PIF to acquire new capabilities for effective oversight of these ventures,” he said.
The report noted that regional volatility is expected to remain, with strong positive growth, driven by Jordan and Iran in 2018 expected to reverse in 2019, and policy shifts, as in Canada’s scaled-back projections, can influence outcomes.
Post-2020 Wood Mackenzie Power & Renewables sees regional demand returning to steady growth as global renewables set more records elsewhere.
“In 2018, developers added 185MW and 63MW of wind capacity in Jordan and Iran, respectively, compared to 53MW of capacity across the entire region in 2017, following a record year for renewables in 2016,” said Malik.
“The completion of the 89MW Al Fujeij and the 86MW Al Rajef projects in 2018 indicates that Jordan has 375MW of the region’s operational 675MW wind capacity.
“Iran followed with 278MW of installed capacity at the end of 2018. A slowdown in 2019 is expected, as project development activity softens in Iran.
“Additionally, delays in awarding the 400MW Dumat Al Jandal project in Saudi Arabia will limit annual capacity additions to 184MW.”
He added that a maturing project pipeline in the region supports the 2020-2021 outlook, even as wind power grew despite Covid-19 globally.
“Saudi Arabian demand serves as the foundation for regional demand. Regional demand diversification is also occurring, with Lebanon set to add 200-400MW to its existing permitted capacity pipeline of 202MW in 2019,” he said
“These developments pave the way for the addition of 2GW of wind capacity between 2019 and 2021.”
Wood Mackenzie Power & Renewables added that the outlook for solar in the region is “much more positive” than wind.
“Compared to only 6GW of wind power capacity, developers will add 53GW of PV capacity through 2024,” said Malik.
He added: “Solar PV, supported by trends such as China’s rapid PV growth in 2016, has become a natural choice for many countries in the region, which is endowed with world class solar energy resources.
“The increased focus on solar energy is demonstrated by ambitious PV targets across the region.”
Canada Wind Energy Costs are plunging as renewable energy auctions, CfD contracts, and efficient turbines drive prices to 2-4 cents/kWh across Alberta and Saskatchewan, outcompeting grid power via competitive bidding and improved capacity factors.
Key Points
Averaging 2-4 cents/kWh via auctions, CfD support, and bigger turbines, wind is now cost-competitive across Canada.
✅ Alberta CfD bids as low as 3.9 cents/kWh.
✅ Turbine outputs rose from 1 MW to 3.3 MW per tower.
✅ Competitive auctions cut costs ~70% over nine years.
It's taken a decade of technological improvement and a new competitive bidding process for electrical generation contracts, but wind may have finally come into its own as one of the cheapest ways to create power.
Ten years ago, Ontario was developing new wind power projects at a cost of 28 cents per kilowatt hour (kWh), the kind of above-market rate that the U.K., Portugal and other countries were offering to try to kick-start development of renewables.
Now some wind companies say they've brought generation costs down to between 2 and 4 cents — something that appeals to provinces that are looking to significantly increase their renewable energy deployment plans.
The cost of electricity varies across Canada, by province and time of day, from an average of 6.5 cents per kWh in Quebec to as much as 15 cents in Halifax.
Capital Power, an Edmonton-based company, recently won a contract for the Whitla 298.8-megawatt (MW) wind project near Medicine Hat, Alta., with a bid of 3.9 cents per kWh, at a time when three new solar facilities in Alberta have been contracted at lower cost than natural gas, underscoring the trend. That price covers capital costs, transmission and connection to the grid, as well as the cost of building the project.
Jerry Bellikka, director of government relations, said Capital Power has been building wind projects for a decade, in the U.S., Alberta, B.C. and other provinces. In that time the price of wind generation equipment has been declining continually, while the efficiency of wind turbines increases.
Increased efficiency
"It used to be one tower was 1 MW; now each turbine generates 3.3 MW. There's more electricity generated per tower than several years ago," he said.
One wild card for Whitla may be steel prices — because of the U.S. and Canada slapping tariffs on one other's steel and aluminum products. Whitla's towers are set to come from Colorado, and many of the smaller components from China.
Canada introduces new surtaxes to curb flood of steel imports
"We haven't yet taken delivery of the steel. It remains to be seen if we are affected by the tariffs." Belikka said.
Another company had owned the site and had several years of meteorological data, including wind speeds at various heights on the site, which is in a part of southern Alberta known for its strong winds.
But the choice of site was also dependent on the municipality, with rural Forty Mile County eager for the development, Belikka said.
Alberta aims for 30% electricity from wind by 2030
Alberta wants 30 per cent of its electricity to come from renewable sources by 2030 and, as an energy powerhouse, is encouraging that with a guaranteed pricing mechanism in what is otherwise a market-bidding process.
While the cost of generating energy for the Alberta Electric System Operator (AESO) fluctuates hourly and can be a lot higher when there is high demand, the winners of the renewable energy contracts are guaranteed their fixed-bid price.
The average pool price of electricity last year in Alberta was 5 cents per kWh; in boom times it rose to closer to 8 cents. But if the price rises that high after the wind farm is operating, the renewable generator won't get it, instead rebating anything over 3.9 cents back to the government.
On the other hand, if the average or pool price is a low 2 cents kWh, the province will top up their return to 3.9 cents.
This contract-for-differences (CfD) payment mechanism has been tested in renewable contracts in the U.K. and other jurisdictions, including some U.S. states, according to AESO.
Competitive bidding in Saskatchewan
In Saskatchewan, the plan is to double its capacity of renewable electricity, to 50 per cent of generation capacity, by 2030, and it uses an open bidding system between the private sector generator and publicly owned SaskPower.
In bidding last year on a renewable contract, 15 renewable power developers submitted bids, with an average price of 4.2 cents per kWh.
One low bidder was Potentia with a proposal for a 200 MW project, which should provide electricity for 90,000 homes in the province, at less than 3 cents kWh, according to Robert Hornung of the Canadian Wind Energy Association.
"The cost of wind energy has fallen 70 per cent in the last nine years," he says. "In the last decade, more wind energy has been built than any other form of electricity."
Ontario remains the leading user of wind with 4,902 MW of wind generation as of December 2017, most of that capacity built under a system that offered an above-market price for renewable power, put in place by the previous Liberal government.
In June of last year, the new Conservative government of Doug Ford halted more than 700 renewable-energy projects, one of them a wind farm that is sitting half-built, even as plans to reintroduce renewable projects continue to advance.
The feed-in tariff system that offered a higher rate to early builders of renewable generation ended in 2016, but early contracts with guaranteed prices could last up to 20 years.
Hornung says Ontario now has an excess of generating capacity, as it went on building when the 2008-9 bust cut market consumption dramatically.
But he insists wind can compete in the open market, offering low prices for generation when Ontario needs new capacity.
"I expect there will be competitive processes put in place. I'm quite confident wind projects will continue to go ahead. We're well positioned to do that."
Cyprus Electricity Interconnectors link the island to the EU grid via EuroAsia and EuroAfrica projects, enabling renewable energy trade, subsea transmission, market liberalization, and stronger energy security and diplomacy across the region.
Key Points
Subsea links connecting Cyprus to Greece, Israel and Egypt for EU grid integration, renewable trade and energy security.
✅ Connects EU, Israel, Egypt via EuroAsia and EuroAfrica
✅ Enables renewables integration and market liberalization
✅ Strengthens energy security, investment, and diplomacy
Electricity interconnectors bridging Cyprus with the broader geographical region, mirroring projects like the Ireland-France grid link already underway in Europe, are crucial for its diplomacy while improving its game to become a clean energy hub.
In an interview with Phileleftheros daily, Andreas Poullikkas, chairman of the Cyprus Energy Regulatory Authority (CERA), said electricity cables such as the EuroAsia Interconnector and the EuroAfrica Interconnector, could turn the island into an energy hub, creating investment opportunities.
“Cyprus, with proper planning, can make the most of its energy potential, turning Cyprus into an electricity producer-state and hub by establishing electrical interconnections, such as the EuroAsia Interconnector and the EuroAfrica Interconnector,” said Poullikkas.
He said these electricity interconnectors, “will enable the island to become a hub for electricity transmission between the European Union, Israel and Egypt, with developments such as the Israel Electric Corporation settlement highlighting regional dynamics, while increasing our energy security”.
Poullikkas argued it will have beneficial consequences in shaping healthy conditions for liberalising the country’s electricity market and economy, facilitating the production of electricity with Renewable Energy Sources and supporting broader efforts like the UK grid transformation toward net zero.
“Electricity interconnections are an excellent opportunity for greater business flexibility in Cyprus, ushering new investment opportunities, as seen with the Lake Erie Connector investment across North America, either in electricity generation or other sectors. Especially at a time when any investment or financial opportunity is welcomed.”
He said Cyprus’ energy resources are a combination of hydrocarbon deposits and renewable energy sources, such as solar.
This combination offers the country a comparative advantage in the energy sector.
Cyprus can take advantage of the development of alternative supply routes of the EU, as more links such as new UK interconnectors come online.
Poullikkas argued that as energy networks are developing rapidly throughout the bloc, serving the ever-increasing needs for electricity, and aligning with the global energy interconnection vision highlighted in recent assessments, the need to connect Cyprus with its wider geographical area is a matter of urgency.
He argues the development of important energy infrastructure, especially electricity interconnections, is an important catalyst in the implementation of Cyprus goals, while recognising how rule changes like Australia's big battery market shift can affect storage strategies.
“It should also be a national political priority, as this will help strengthen diplomatic relations,” added Poullikkas.
Implementing the electricity interconnectors between Israel, Cyprus and Greece through Crete and Attica (EuroAsia Interconnector) has been delayed by two years.
He said the delay was brought about after Greece decided to separate the Crete-Attica section of the interconnection and treat as a national project.
Poullikkas stressed the Greek authorities are committed to ensuring the connection of Cyprus with the electricity market of the EU.
“All the required permits have been obtained from the competent authorities in Cyprus and upon the completion of the procedures with the preferred manufacturers, construction of the Cyprus-Crete electrical interconnection will begin before the end of this year. Based on current data, the entire interconnection is expected to be implemented in 2023”.
“The EuroAfrica Interconnector is in the pre-works stage, all project implementation studies have already been completed and submitted to the competent authorities, including cost and benefit studies”.
EuroAsia Interconnector is a leading EU project of common interest (PCI), also labelled as an “electricity highway” by the European Commission.
It connects the national grids of Israel, Cyprus and Greece, creating a reliable energy bridge between the continents of Asia and Europe allowing bi-directional transmission of electricity.
The cost of the entire subsea cable system, at 1,208km, the longest in the world and the deepest at 3,000m below sea level, is estimated at €2.5 bln.
Construction costs for the first phase of the Egypt-Cyprus interconnection (EuroAfrica) with a Stage 1 transmission capacity of 1,000MW is estimated at €1bln.
The Cyprus-Greece (Crete) interconnection, as well as the Egypt-Cyprus electricity interconnector, will both be commissioned by December 2023.
PG&E 2024 Rate Hikes signal sharp increases to fund wildfire safety, infrastructure upgrades, and CPUC-backed reliability, with rates expected to stabilize in 2025, affecting rural residents, businesses, and high-risk zones across California.
Key Points
PG&E’s 2024 hikes fund wildfire safety and grid upgrades, with pricing expected to stabilize in 2025.
✅ Driven by wildfire safety, infrastructure, and reinsurance costs
✅ Largest impacts in rural, high-risk zones; business rates vary
✅ CPUC oversight aims to ensure necessary, justified investments
Pacific Gas and Electric (PG&E) is expected to implement a series of rate hikes that, amid analyses of why California electricity prices are soaring across the state, will significantly impact California residents. These increases, while substantial, are anticipated to be followed by a period of stabilization in 2025, offering a sense of relief to customers facing rising costs.
PG&E, one of the largest utility providers in the state, announced that its 2024 rate hikes are part of efforts to address increasing operational costs, including those related to wildfire safety, infrastructure upgrades, and regulatory requirements. As California continues to face climate-related challenges like wildfires, utilities like PG&E are being forced to adjust their financial models to manage the evolving risks. Wildfire-related liabilities, which have plagued PG&E in recent years, play a significant role in these rate adjustments. In response to previous fire-related lawsuits, including a bankruptcy plan supported by wildfire victims that reshaped liabilities, and the increased cost of reinsurance, PG&E has made it clear that customers will bear part of the financial burden.
These rate hikes will have a multi-faceted impact. Residential users, particularly those in rural or high-risk wildfire zones, will see some of the largest increases. Business customers will also be affected, although the adjustments may vary depending on the size and energy consumption patterns of each business. PG&E has indicated that the increases are necessary to secure the utility’s financial stability while continuing to deliver reliable service to its customers.
Despite the steep increases in 2024, PG&E's executives have assured that the company's pricing structure will stabilize in 2025. The utility has taken steps to balance the financial needs of the business with the reality of consumer affordability. While some rate hikes are inevitable given California's regulatory landscape and climate concerns, PG&E's leadership believes the worst of the increases will be seen next year.
PG&E’s anticipated stabilization comes after a year of scrutiny from California regulators. The California Public Utilities Commission (CPUC) has been working closely with PG&E to scrutinize its rate request and ensure that hikes are justifiable and used for necessary investments in infrastructure and safety improvements. The CPUC’s oversight is especially crucial given the company’s history of safety violations and the public outrage over past wildfire incidents, including reports that its power lines may have sparked fires in California, which have been linked to PG&E’s equipment.
The hikes, though significant, reflect the broader pressures facing utilities in California, where extreme weather patterns are becoming more frequent and intense due to climate change. Wildfires, which have grown in severity and frequency in recent years, have forced PG&E to invest heavily in fire prevention and mitigation strategies, including compliance with a judge-ordered use of dividends for wildfire mitigation across its service area. This includes upgrading equipment, inspecting power lines, and implementing more rigorous protocols to prevent accidents that could spark devastating fires. These investments come at a steep cost, which PG&E is passing along to consumers through higher rates.
For homeowners and businesses, the potential for future rate stabilization offers a glimmer of hope. However, the 2024 increases are still expected to hit consumers hard, especially those already struggling with high living costs. The steep hikes have prompted public outcry, with calls for action as bills soar amplifying advocacy group arguments that utilities should absorb more of the costs related to climate change and fire prevention instead of relying on ratepayers.
Looking ahead to 2025, the expectation is that PG&E’s rates will stabilize, but the question remains whether they will return to pre-2024 levels or continue to rise at a slower rate. Experts note that California’s energy market remains volatile, and while the rates may stabilize in the short term, long-term cost management will depend on ongoing investments in renewable energy sources and continued efforts to make the grid more resilient to climate-related risks.
As PG&E navigates this challenging period, the company’s commitment to transparency and working with regulators will be crucial in rebuilding trust with its customers. While the immediate future may be financially painful for many, the hope is that the utility's focus on safety and infrastructure will lead to greater long-term stability and fewer dramatic rate increases in the years to come.
Ultimately, California residents will need to brace for another tough year in terms of utility costs but can find reassurance that PG&E’s rate increases will eventually stabilize. For those seeking relief, there are ongoing discussions about increasing energy efficiency, exploring renewable energy alternatives, and expanding assistance programs for lower-income households to help mitigate the financial strain of these price hikes.
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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