Bulky and obtrusive rack-mounted solar panels may be a thing of the past.
Spurred by recent advances in technology, solar panel makers are scrambling to come up with neater and cleaner products that will overcome the aesthetic objections of home owners to traditional solar panels.
They are building their technology directly into different kinds of roof tiles, hiding them in walls and lining the tops of patio awnings with them.
"Bottom line, people don't want goofy looking roofs," said Julie Blunden of solar panel manufacturer SunPower Corp.
SunPower is making solar panels designed to work seamlessly with both flat roof tiles and the curved, Spanish-style clay tiles popular in parts of California and other sunny places. SunPower, controlled by Cypress Semiconductor, is the leading U.S. manufacturer, but has half its sales in Europe.
Lumeta, a division of DRI Energy, has similar integrated panels in the final stages of industry certification, manufactured by China's Suntech Power Holdings Corp.
Both SunPower's and Lumeta's panels are made using silicon, the same raw material used in solar panels since the 1950s. Advances in technology using a new semiconductor called copper indium gallium selenide (CIGS) promises much thinner panels that are easier to hide.
For now though, thin-film panels are less efficient than silicon and manufacturers such as DayStar Technologies Inc are focusing on the commercial market because of economies of scale.
"Because it's capital-intensive, the way to get cost down is to get volume up, so the thin-film manufacturers are looking for more high volume production applications - that's how you can get the cost parity to silicon," said Bret Adams, a spokesperson for DayStar.
Although thin film is a relatively new technology, John Langdon of thin-film start-up HelioVolt said he expects it to dominate residential use as it becomes part of the building process.
"Solar power today is where air conditioning was in 1950 - everything is a window unit designed for retrofit on existing construction - its more expensive, its not as good, its not as a cost effective," Langdon said. "But by 1960 no one built a building without saying 'Should I put a central air system in?' - and the same thing is going to happen with solar."
Until recently, solar panels were about six inches thick and mounted with brackets on top of existing roofs or custom designed racks.
But with energy prices climbing, and authorities offering subsidies for solar power, the solar industry is beginning to recognize aesthetics as one of the last barriers to solar power in the residential market, despite a housing slump in the United States.
"At first you don't even notice they're solar," said Tony Fortenberry, who bought a home in Rockland, California, in September with solar panels manufactured by SunPower on its roof.
"The tiles are completely integrated into the roof," Fortenberry said. "It has a more elegant appearance and it doesn't look like an add-on."
The number of solar installations in the United States rose 45 percent to 150 megawatts in 2007, according to the Solar Energy Industry Association, or the equivalent of the total energy use of about 37,500 homes.
Total solar capacity of 3,400 MW, not including pool or lighting systems, was less than 1 percent of U.S. annual use last year, leaving plenty of room for growth.
Although such aesthetic designs are more expensive than the rack-mounted systems, they appear to make sense in new developments, where reduced installation costs and less-invasive designs can help convince builders and prospective buyers of the merits of solar power.
According to SunPower's Blunden, the solar business is dependent on builders, who must be convinced that it is cost-efficient and that buyers will like the way they look.
In the United States, a typical market price for retro-fit add-on systems is about $8 per watt, split roughly equally between hardware and installation. This translates into about $40,000 for a 5 kilowatt system, before government subsidies and reimbursements.
Another product, Lumeta's PowerPly, which has adhesive backing, eliminates the need for a rack-mounted systems and can reduce installation costs by about 70 percent.
For homeowner Fortenberry, the integrated roof was so successful that he questions why the developer didn't go a step further.
"Why do I have a solar panel integrated into my roof? Why isn't my entire roof a solar panel?"
Ukraine-ENTSO-E Grid Synchronization links Ukraine and Moldova to the European grid via secure interconnection, matching frequency for stability, resilience, and energy security, enabling cross-border support, islanding recovery, and coordinated load balancing during wartime disruptions.
Key Points
Rapid alignment of Ukraine and Moldova into the European grid to enable secure interconnection and system stability.
✅ Matches 50 Hz frequency across interconnected systems
✅ Enables cross-border support and electricity trading
✅ Improves resilience, stability, and energy security
On February 24 Ukraine’s electric grid operator disconnected the country’s power system from the larger Russian-operated network to which it had always been linked. The long-planned disconnection was meant to be a 72-hour trial proving that Ukraine could operate on its own and to protect electricity supply before winter as contingencies were tested. The test was a requirement for eventually linking with the European grid, which Ukraine had been working toward since 2017. But four hours after the exercise started, Russia invaded.
Ukraine’s connection to Europe—which was not supposed to occur until 2023—became urgent, and engineers aimed to safely achieve it in just a matter of weeks. On March 16 they reached the key milestone of synchronizing the two systems. It was “a year’s work in two weeks,” according to a statement by Kadri Simson, the European Union commissioner for energy. That is unusual in this field. “For [power grid operators] to move this quickly and with such agility is unprecedented,” says Paul Deane, an energy policy researcher at the University College Cork in Ireland. “No power system has ever synchronized this quickly before.”
Ukraine initiated the process of joining Europe’s grid in 2005 and began working toward that goal in earnest in 2017, as did Moldova. It was part of an ongoing effort to align with Europe, as seen in the Baltic states’ disconnection from the Russian grid, and decrease reliance on Russia, which had repeatedly threatened Ukraine’s sovereignty. “Ukraine simply wanted to decouple from Russian dominance in every sense of the word, and the grid is part of that,” says Suriya Jayanti, an Eastern European policy expert and former U.S. diplomat who served as energy chief at the U.S. embassy in Kyiv from 2018 to 2020.
After the late February trial period, Ukrenergo, the Ukrainian grid operator, had intended to temporarily rejoin the system that powers Russia and Belarus. But the Russian invasion made that untenable. “That left Ukraine in isolation mode, which would be incredibly dangerous from a power supply perspective,” Jayanti says. “It means that there’s nowhere for Ukraine to import electricity from. It’s an orphan.” That was a particularly precarious situation given Russian attacks on key energy infrastructure such as the Zaporizhzhia nuclear power plant and ongoing strikes on Ukraine’s power grid that posed continuing risks. (According to Jayanti, Ukraine’s grid was ultimately able to run alone for as long as it did because power demand dropped by about a third as Ukrainians fled the country.)
Three days after the invasion, Ukrenergo sent a letter to the European Network of Transmission System Operators for Electricity (ENTSO-E) requesting authorization to connect to the European grid early. Moldelectrica, the Moldovan operator, made the same request the following day. While European operators wanted to support Ukraine, they had to protect their own grids, amid renewed focus on protecting the U.S. power grid from Russian hacking, so the emergency connection process had to be done carefully. “Utilities and system operators are notoriously risk-averse because the job is to keep the lights on, to keep everyone safe,” says Laura Mehigan, an energy researcher at University College Cork.
An electric grid is a network of power-generating sources and transmission infrastructure that produces electricity and carries it from places such as power plants, wind farms and solar arrays to houses, hospitals and public transit systems. “You can’t just experiment with a power system and hope that it works,” Deane says. Getting power where it is it needed when it is needed is an intricate process, and there is little room for error, as incidents involving Russian hackers targeting U.S. utilities have highlighted for operators worldwide.
Crucial to this mission is grid interconnection. Linked systems can share electricity across vast areas, often using HVDC technology, so that a surplus of energy generated in one location can meet demand in another. “More interconnection means we can move power around more quickly, more efficiently, more cost effectively and take advantage of low-carbon or zero-carbon power sources,” says James Glynn, a senior research scholar at the Center on Global Energy Policy at Columbia University. But connecting these massive networks with many moving parts is no small order.
One of the primary challenges of interconnecting grids is synchronizing them, which is what Ukrenergo, Moldelectrica and ENTSO-E accomplished last week. Synchronization is essential for sharing electricity. The task involves aligning the frequencies of every energy-generation facility in the connecting systems. Frequency is like the heartbeat of the electric grid. Across Europe, energy-generating turbines spin 50 times per second in near-perfect unison, and when disputes disrupt that balance, slow clocks across Europe can result, reminding operators of the stakes. For Ukraine and Moldova to join in, their systems had to be adjusted to match that rhythm. “We can’t stop the power system for an hour and then try to synchronize,” Deane says. “This has to be done while the system is operating.” It is like jumping onto a moving train or a spinning ride at the playground: the train or ride is not stopping, so you had better time the jump perfectly.
bGen Thermal Energy Storage stores high-temperature heat in crushed rocks, enabling on-demand steam, hot water, or hot air; integrates renewables, shifts load with off-peak electricity, and decarbonizes campus heating at SUNY Purchase with NYPA.
Key Points
A rock-based TES system storing heat to deliver steam, hot water, or hot air using renewables or off-peak power.
✅ Uses crushed rocks to store high-temperature heat
✅ Cuts about 550 metric tons CO2 annually at SUNY Purchase
✅ Integrates renewables and off-peak electricity with NYPA
Brenmiller Energy Ltd. (NASDAQ: BNRG), in collaboration with the New York Power Authority (NYPA), a utility pursuing grid software modernization to improve reliability, has successfully deployed its first bGen™ thermal energy storage (TES) system in the United States at the State University of New York (SUNY) Purchase College. This milestone project, valued at $2.5 million, underscores the growing role of TES in advancing sustainable energy solutions.
Innovative TES Technology
The bGen™ system utilizes crushed rocks to store high-temperature heat, which can be harnessed to generate steam, hot air, or hot water on demand. This approach allows for the efficient use of excess renewable energy or off-peak electricity, and parallels microreactor storage advances that broaden thermal options, providing a reliable and cost-effective means of meeting heating needs. At SUNY Purchase College, the bGen™ system is designed to supply nearly 100% of the heating requirements for the Physical Education Building.
Environmental Impact
The implementation of the bGen™ system is expected to eliminate approximately 550 metric tons of greenhouse gas emissions annually. This reduction aligns with New York State's ambitious climate goals, including a 40% reduction in greenhouse gas emissions by 2030, even as transmission constraints can limit cross-border imports. The project also demonstrates the potential of TES to support the state's transition to a cleaner and more resilient energy system.
Collaborative Effort
The successful deployment of the bGen™ system at SUNY Purchase College is the result of a collaborative effort between Brenmiller Energy and NYPA. The project was partially funded by a grant from the Israel-U.S. Binational Industrial Research and Development (BIRD) Foundation. This partnership highlights the importance of international cooperation in advancing innovative energy technologies, as seen in OPG-TVA nuclear collaboration efforts across North America.
Future Prospects
The successful installation and operation of the bGen™ system at SUNY Purchase College serve as a model for broader adoption of TES technology in institutional settings, as OPG's SMR commitment signals parallel low-carbon investment across the region. Brenmiller Energy and NYPA plan to share the project's findings through a webinar hosted by the Renewable Thermal Collaborative on May 19, 2025. This initiative aims to promote the scalability and replicability of TES solutions across New York State and beyond.
As the demand for sustainable energy solutions continues to grow, the successful deployment of the bGen™ system at SUNY Purchase College marks a significant step forward in the integration of TES technology into the U.S. energy landscape, while projects like Pickering B refurbishment underscore parallel clean power investments. The project not only demonstrates the feasibility of TES but also sets a precedent for future initiatives aimed at reducing carbon emissions and enhancing energy efficiency.
Brenmiller Energy's commitment to innovation and sustainability positions the company as a key player in the evolving energy sector. With continued support from partners like NYPA and the BIRD Foundation, and as jurisdictions advance first SMR deployments in North America, Brenmiller Energy is poised to expand the reach of its TES solutions, contributing to a more sustainable and resilient energy future.
UAE Barakah Nuclear Plant connects Unit 1 to the grid, supplying clean electricity, nuclear baseload power, and lower carbon emissions, with IAEA oversight, FANR regulation, and South Korea collaboration, supporting energy security and economic diversification.
Key Points
The UAE Barakah Nuclear Plant is a four-reactor project delivering clean baseload power and reducing CO2.
✅ Unit 1 online; four reactors to supply 25% of UAE electricity
✅ Cuts 21 million tons CO2 annually; clean baseload for grid
✅ FANR-licensed; IAEA and WANO oversight ensure safety
Unit 1 of the UAE’s Barakah plant — the Arab world’s first nuclear energy plant in the region — has connected to the national power grid, in a historic moment enabling it to provide cleaner electricity to millions of residents and help reduce the oil-rich country’s reliance on fossil fuels.
“This is a major milestone, we’ve been planning for this for the last 12 years now,” Mohamed Al Hammadi, CEO of Emirates Nuclear Energy Corporation (ENEC), told CNBC’s Dan Murphy in an exclusive interview ahead of the news.
Unit 1, which has reached 100% power as it steps closer to commercial operations, is the first of what will eventually be four reactors, which when fully operational are expected to provide 25% of the UAE’s electricity and reduce its carbon emissions by 21 million tons a year, according to ENEC. That’s roughly equivalent to the carbon emissions of 3.2 million cars annually.
The Gulf country of nearly 10 million is the newest member of a group of now 31 countries running nuclear power operations. It’s also the first new country to launch a nuclear power plant in three decades, the last being China’s nuclear energy program in 1990.
“The UAE has been growing from an electricity demand standpoint,” Al Hammadi said. “That’s why we are trying to meet the demand (and) at the same time have it with less carbon emissions.”
The UAE’s electricity mix will continue to include gas and renewable energy, with “the baseload from nuclear,” including emerging next-gen nuclear designs, the CEO added, which he described as a “safe, clean and reliable source of electricity” for the country.
The project is also providing “highly compensated jobs” for the Emiratis and will introduce new industries for the country’s economy, Al Hammadi said. The company noted that it has awarded roughly 2,000 contracts worth more than $4.8 billion for local companies.
International collaboration The UAE’s nuclear watchdog FANR, the Federal Authority for Nuclear Regulation, granted the operating license for Unit 1 in February, after an extensive inspection process to ensure the plant’s compliance with regulatory requirements. The license is expected to last 60 years. The program also involved collaboration with external bodies including the U.N.’s International Atomic Energy Agency (IAEA) and the government of South Korea, and its pre-start-up review was completed in January by the World Association of Nuclear Operators (WANO). The WANO and the IAEA have conducted over 40 inspection and review missions at Barakah.
But the project has its critics, particularly some experts from the independent Nuclear Consulting Group non-profit, who have expressed concern about Barakah’s safety features and potential environmental risks.
In response, ENEC said the “adherence to the highest standards of safety, quality and security is deeply embedded within the fabric of the UAE Peaceful Nuclear Energy Program.”
“The Barakah Plant meets all national and international regulatory requirements and standards for nuclear safety,” a company statement said. It added that the reactor design had been certified by the Korea Institute of Nuclear Safety, FANR and the US-based Nuclear Regulatory Commission, “demonstrating the robustness of this design for safety and operating reliability.”
Worries of regional proliferation The achievement for the UAE is particularly significant given tensions in the wider region over nuclear proliferation.
Some observers have warned of a regional arms race, though the UAE already partakes in what nuclear energy experts call the “gold standard” of civilian nuclear partnerships: The U.S.-UAE 123 Agreement for Peaceful Civilian Nuclear Energy Cooperation. It allows the UAE to receive nuclear materials, equipment and know-how from the U.S. while precluding it from developing dual-use technology by barring uranium enrichment and fuel reprocessing, the processes required for building a bomb.
By contrast, nearby Iran has suspended its compliance to the multilateral 2015 deal that regulated its nuclear power development and many fear its approach toward bomb-making capability. Meanwhile, Saudi Arabia has voiced its desire to develop a nuclear energy program without adhering to a 123 agreement.
And most recently, in the wake of a historic deal that has seen the UAE become the first Gulf country to normalize relations with Israel, Iran responded by warning the agreement would bring a “dangerous future” for the Emirati government.
But ENEC and UAE officials emphasize the program’s commitment to safety, transparency and international cooperation, and its necessity for meeting growing electricity demand by cleaner means.
“The nuclear industry is growing, with milestones around the world being reached, and the UAE is no exception. We are pursuing our electricity demand to meet that in a safe, secure and stable manner, and also doing it in an environmentally friendly way,” Al Hammadi said.
“Having four reactors that will provide 25% of electricity for the nation and will avoid us emitting 21 million tons of CO2 on an annual basis, as part of a broader green industrial revolution approach, is a very serious step to take — and the UAE is not talking about it, it is doing it, and we are reaping the benefits of it as we speak right now.”
Global Renewable Electricity Milestone signals solar, wind, hydro, and geothermal surpass 30% of power generation, driven by falling costs, battery storage, smart grids, and ambitious policy targets that strengthen energy security and decarbonization.
Key Points
It marks renewables exceeding 30% of global power, enabled by cheaper tech, storage, and strong policy.
✅ Costs of solar and wind fall, boosting competitiveness
✅ Storage and smart grids improve reliability and flexibility
✅ Policies target decarbonization while ensuring just transition
A recent report by the energy think tank Ember marks a significant milestone in the global energy transition. For the first time ever, according to their analysis, renewable energy sources like solar, wind, hydro, and geothermal now account for more than 30% of the world's electricity generation, a milestone echoed by wind and solar growth globally. This achievement signifies a pivotal shift towards a cleaner and more sustainable energy future.
The report attributes this growth to several key factors. Firstly, the cost of renewable energy technologies like solar panels and wind turbines has plummeted in recent years, making them increasingly competitive with traditional fossil fuels. Secondly, advancements in battery storage technology are facilitating the integration of variable renewable sources like solar and wind into the grid, addressing concerns about reliability. Thirdly, a growing number of countries are implementing ambitious renewable energy targets and policies, driven by environmental concerns and the desire for energy security.
The rise of renewables is not uniform across the globe. Europe leads the pack, with the European Union generating a staggering 44% of its electricity from renewable sources in 2023. Countries like Denmark, Germany, and Spain are at the forefront of this clean energy revolution. Developing nations are also starting to embrace renewables, driven by factors like falling technology costs and the need for affordable electricity access.
However, challenges remain. Fossil fuels still dominate the global energy mix, accounting for roughly two-thirds of electricity generation. Integrating a higher proportion of variable renewables into the grid necessitates robust storage solutions and smart grid technologies. Additionally, the transition away from fossil fuels needs to be managed carefully to ensure a just and equitable outcome for workers in the coal, oil, and gas sectors.
Despite these challenges, the report by Ember paints an optimistic picture. The rapid growth of renewables demonstrates their increasing viability and underscores the global commitment to a cleaner energy future, and in the United States, for example, renewables are projected to reach one-fourth of U.S. electricity generation, reinforcing this trajectory. The report also highlights the economic benefits of renewables, with new jobs created in the clean energy sector and reduced reliance on volatile fossil fuel prices.
Looking ahead, continued technological advancements, supportive government policies, and increased investment in renewable energy infrastructure are all crucial for further growth, with scenarios such as BNEF's 2050 outlook suggesting wind and solar could provide half of electricity, underscoring the importance of sustained effort. Furthermore, international cooperation is essential to ensure a smooth and equitable global energy transition. Developed nations can play a vital role by sharing technology and expertise with developing countries.
The 30% milestone is a significant step forward, but it's just the beginning. As the world strives to combat climate change and ensure energy security for future generations, renewables are poised to play a central role in powering a sustainable future, with wind and solar surpassing coal in the U.S. offering a clear signal of the shift. The report by Ember serves as a powerful reminder that a clean energy future is not just a dream, but a rapidly unfolding reality.
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.
BC Hydro Holiday Electricity Usage is set to rise as energy demand increases during peak 4-10 pm on Christmas and Boxing Day, driven by larger gatherings, more cooking, and eased COVID-19 restrictions province-wide.
Key Points
Expected rise in power demand on Christmas and Boxing Day evenings versus 2020, driven by larger gatherings and cooking.
✅ Peak hours 4-10 pm expected to rise in provincial load.
✅ 2020 saw 4% and 7% drops vs 2019 on Christmas and Boxing Day.
✅ Holiday lighting adds ~3% to use; switching to LED can save ~$40.
BC Hydro data showed residential electricity load in the Cariboo and throughout the province, even as drought affects generation dynamics heading into winter, dropped on Christmas Day and Boxing Day in 2020.
Northern Community Relations Manager, Bob Gammer, said the decrease was due in part to more people following the COVID-19 restrictions and not getting together for big meals, even though 2018 Earth Hour usage increased elsewhere illustrates how behavior can sometimes raise demand.
However, this year Gammer said between 4 and 10 pm on those two days, BC Hydro does expect to see a change in overall usage, aligning with all-time high demand trends reported recently in B.C.
“On Christmas Day and Boxing Day, we expect to see increases through those hours and a little bit more so between 4 and 10 pm we should see the amount of power being consumed across the province, as record-breaking 2021 demand indicated earlier, going up compared to what it was on those two days last year.”
In 2020 on Christmas Day evening hydro usage dropped by over 4 percent and Boxing Day evening decreased by 7 percent compared to 2019, whereas regions like Calgary's winter demand have seen spikes during extreme cold.
Gammer added after BC Hydro surveyed their customers and introduced a winter payment plan, they expect to see a lot more cooking happening on Christmas Day and Boxing Day this year as people are intending to have larger gatherings and visit friends.
We asked Gammer about hydro usage when it comes to homes decked out for the holidays, and how that compares to newer loads like crypto mining activity in B.C.
“The Christmas lighting displays people have, not just indoors but outdoors as well, what we’re seeing is about a 3 percent increase in electricity consumption overall through the Christmas season. If people switch, if you still have older lights that are incandescent, switch those over to LED, and through the season it could wind up saving you $40 in electricity just switching over about 8 strings of lights to LED.”
