The operator of Dounreay nuclear power plant in Caithness admitted illegally dumping radioactive waste and releasing nuclear fuel particles into the sea more than 40 years ago.
The UK Atomic Energy Authority (UKAEA) pled guilty to four charges under the Radioactive Substances Act 1960: one of disposing of radioactive waste at a landfill site at the plant between 1963 and 1975 and three of allowing nuclear fuel particles to be released into the Pentland Firth between 1963 and 1984.
The charges were brought after UKAEAwas reported to the procurator-fiscal following a lengthy investigation by the Scottish Environment Protection Agency (Sepa).
Wick Sheriff Court heard yesterday that fuel fragments which were supposed to be disposed of in a storage shaft had been put in 46,000 cubic metres of landfill. The error came to light in July 1999.
Alasdair MacDonald, procurator-fiscal forCaithness, Sutherland and Easter Ross, said six radioactive particles were removed from the landfill and two from the coast.
He added that such solid radioactive waste could only have legally been disposed of in a low-level pit. Between December 1963 and December 1984, nuclear particles entered the sea from a drain.
The court heard was told that this drain was supposed to contain only liquid waste, but storage tanks were not properly filtered, allowing contaminated material to escape.
Mr MacDonald told the court that, between 1976 and the end of 2006, 1401 radioactive particles were recovered by UKAEA from the foreshore and nearby Sandside Beach.
He said Sepa had found between 1000 and 4000 particles within 15ft of an overflow pipe at Dounreay.
UKAEA also admitted allowing fragments to escape from two other pipes at the site.
Mr. MacDonald said: "This appears to be a clear unauthorised disposal of solid radioactive waste as a matter of incompetence. It has not only lasting consequences for the future, but provides a clear signpost back to the mistakes of the past. Particles were literally flushed out to sea over a 20-year period."
Mr. MacDonald said four nuclear fragments recovered from Dounreay's foreshore and two from the sea bed were considered "very dangerous" and could be fatal if ingested.
David Stewart, for UKAEA, said it was accepted that a small amount of radioactive material had been found in the landfill site and had been released into the sea. But a study had shown only an extremely small possibility of a member of the public coming into contact with a particle on local beaches.
Sheriff Andrew Berry deferred sentence until February 15.
Dr John Crofts, director of safety with UKAEA, said outside the court: "UKAEA deeply regrets that some particles were released from the site. The practices which gave rise to these particles ceased long ago."
A spokesman for Friends of the Earth Scotland said these incidents illustrate "the idiocy of considering an expansion of nuclear power in Scotland".
Dounreay, a former fast reactor research and development centre, was shut in 1994 and is earmarked for a GBP2.9bn decommissioning by 2033.
Last year UKAEA was fined GBP2m after 266 litres of hazardous, dissolved spent fuel spilled on to a laboratory floor at the plant.
Champlain Hudson Power Express Converter Station brings Canadian hydropower via HVDC to Queens, converting 1,250 MW to AC for New York City's grid, replacing a retired fossil site with a zero-emission, grid-scale clean energy hub.
Key Points
A Queens converter turning 1,250 MW HVDC hydropower into AC for NYC's grid, repurposing an Astoria fossil site.
✅ 340-mile underwater/underground HVDC link from Quebec to Queens
✅ 1,250 MW DC-AC conversion feeding directly into NY grid by 2026
New York Governor Kathy Hochul has announced the start of construction on the converter station of the Champlain Hudson Power Express transmission line, a project to bring electricity generated from Canadian hydropower to New York City.
The 340 mile (547 km) transmission line is a proposed underwater and underground high-voltage direct current power transmission line to deliver the power from Quebec, Canada, to Queens, New York City. The project is being developed by Montreal-based public utility Hydro-Quebec (QBEC.UL) and its U.S. partner Transmission Developers, while neighboring New Brunswick has signed NB Power deals to bring more Quebec electricity into the province.
The converter station for the line will be the first-ever transformation of a fossil fuel site into a grid-scale zero-emission facility in New York City, its backers say.
Workers have already removed six tanks that previously stored 12 million gallons (45.4 million liters) of heavy oil for burning in power plants and nearly four miles (6.44 km) of piping from the site in the Astoria, Queens neighborhood, echoing Hydro-Quebec's push to wean the province off fossil fuels as regional power systems decarbonize.
The facility is expected to begin operating in 2026, even as the Ontario-Quebec power deal was not renewed elsewhere in the region. Once the construction is completed, it will convert 1,250 megawatts of energy from direct current to alternating current power that will be fed directly into the state's power grid, helping address transmission constraints that have impeded incremental Quebec-to-U.S. power deliveries.
“Renewable energy plays a critical role in the transformation of our power grid while creating a cleaner environment for our future generations,” Hochul said. The converter station is a step towards New York’s target for 70% of the state’s electricity to come from renewable sources by 2030, as neighboring Quebec has closed the door on nuclear power and continues to lean on hydropower.
OPG-TVA SMR Partnership advances advanced nuclear technology and small modular reactors for 24/7 carbon-free baseload power, enabling net-zero goals, cross-border licensing, and deployment within a North American clean energy hub.
Key Points
A cross-border effort by OPG and TVA to develop, license, and deploy SMRs for reliable, carbon-free baseload power.
✅ Coordinates design, licensing, construction, and operations
✅ Supports 24/7 baseload, net-zero targets, and energy security
✅ Leverages Darlington and Clinch River early site permits
Two of North America's leading nuclear utilities unveiled a pioneering partnership to develop advanced nuclear technology as an integral part of a clean energy future and creating a North American energy hub. Ontario Power Generation, whose OPG's SMR commitment is well established, and the Tennessee Valley Authority will jointly work to help develop small modular reactors as an effective long-term source of 24/7 carbon-free energy in both Canada and the U.S.
The agreement allows the companies to coordinate their explorations into the design, licensing, construction and operation of small modular reactors.
"As leaders in our industry and nations, OPG and TVA share a common goal to decarbonize energy generation while maintaining reliability and low-cost service, which our customers expect and deserve," said Jeff Lyash, TVA President and CEO. "Advanced nuclear technology will not only help us meet our net-zero carbon targets but will also advance North American energy security."
"Nuclear energy has long been key to Ontario's clean electricity grid, and is a crucial part of our net-zero future," said Ken Hartwick, OPG President and CEO. "Working together, OPG and TVA will find efficiencies and share best practices for the long-term supply of the economical, carbon-free, reliable electricity our jurisdictions need, supported by ongoing Pickering life extensions across Ontario's fleet."
OPG and TVA have similar histories and missions. Both are based on public power models that developed from renewable hydroelectric generation before adding nuclear to their generation mixes. Today, nuclear generation accounts for significant portions of their carbon-free energy portfolios, with Ontario advancing the Pickering B refurbishment to sustain capacity.
Both are also actively exploring SMR technologies. OPG is moving forward with plans to deploy an SMR at its Darlington nuclear facility in Clarington, ON, as part of broader Darlington SMR plans now underway. The Darlington site is the only location in Canada licensed for new nuclear with a completed and accepted Environmental Assessment. TVA currently holds the only Nuclear Regulatory Commission Early Site Permit in the U.S. for small modular reactor deployment at its Clinch River site near Oak Ridge, TN.
No exchange of funding is involved. However, the collaboration agreement will help OPG and TVA reduce the financial risk that comes from development of innovative technology, as well as future deployment costs.
"TVA has the most recent experience completing a new nuclear plant in North America at Watts Bar and that knowledge is invaluable to us as we work toward the first SMR groundbreaking at Darlington," said Hartwick. "Likewise, because we are a little further along in our construction timing, TVA will gain the advantage of our experience before they start work at Clinch River."
"It's a win-win agreement that benefits all of those served by both OPG and TVA, as well as our nations," said Lyash. "Moving this technology forward is not only a significant step in advancing a clean energy future and Canada's climate goals, but also in creating a North American energy hub."
"With the demand for clean electricity on the rise around the world, Ontario's momentum is growing. The world is watching Ontario as we advance our work to fully unleash our nuclear advantage, alongside a premiers' SMR initiative that underscores provincial collaboration. I congratulate OPG and TVA – two great industry leaders – for working together to deploy SMRs and showcase and apply Canada's nuclear expertise that will deliver economic, health and environmental benefits for all of us to enjoy," said Todd Smith,Ontario Minister of Energy.
"The changing climate is a global crisis that requires global solutions. The partnership between the Tennessee Valley Authority and Ontario Power Generation to develop and deploy advanced nuclear technology is exactly the kind of innovative collaboration that is needed to quickly bring the next generation of nuclear carbon-free generation to market. I applaud the leadership that both companies are demonstrating to further strengthen our cross-border relationships," said Maria Korsnick, President and CEO, Nuclear Energy Institute.
Smart Renewables and Electrification Pathways Program enables clean energy and grid modernization across Canada, funding wind, solar, hydro, geothermal, tidal, and storage to cut GHG emissions and accelerate electrification toward a net-zero economy.
Key Points
A $964M Canadian program funding clean power and grid upgrades to cut emissions and build net-zero electrified economy.
✅ Funds wind, solar, hydro, geothermal, tidal, and storage projects
✅ Modernizes grids for reliability, digitalization, and resilience
✅ Supports net-zero by 2050 with Indigenous and utility partners
Harnessing Canada's immense clean energy resources requires transformational investments to modernize our electricity grid. The Government of Canada is investing in renewable energy and upgrading the electricity grid, moving toward an electric, connected and clean economy, to make clean, affordable electricity options more accessible in communities across Canada.
The Honourable Seamus O'Regan Jr., Minister of Natural Resources, today launched a $964-million program, alongside a recent federal green electricity contract in Alberta that underscores momentum, to support smart renewable energy and grid modernization projects that will lower emissions by investing in clean energy technologies, like wind, solar, storage, hydro, geothermal and tidal energy across Atlantic Canada.
The Smart Renewables and Electrification Pathways Program (SREPs) supports building Canada's low-emissions energy future and a renewable, electrified economy through projects that focus on non-emitting, cleaner energy technologies, such as storage, and modernizing electricity system operations.
Investing in these technologies reduces greenhouse gas emissions by creating a cleaner, more connected electrical system, supporting progress toward zero-emissions electricity by 2035 goals, while helping Canada reach net-zero emissions by 2050.
Minister O'Regan launched the program during the Canadian Electricity Association's (CEA) virtual regulatory forum on Electricity Regulation & the Four Disruptors – Decarbonization, Decentralization, Digitalization and Democratization, highlighting evolving regulatory approaches as B.C. streamlines clean energy approvals to support deployment nationwide. The launch also coincides with Canadian Environment Week, which celebrates Canada's environmental accomplishments and encourages Canadians to contribute to conserving and protecting the environment.
Through SREPs and other programming, the government is working with provinces and territories, with the Prairie Provinces leading renewable growth in the years ahead, utilities, Indigenous partners and others, including diverse businesses and communities, to deliver these clean and reliable energy initiatives. With Canadian innovation, technology and skilled energy workers, we can provide more communities, households and businesses with an increased supply of clean electricity and a cleaner electrical grid.
To help interested stakeholders find information on SREPs, a new webpage has been launched, which includes a comprehensive guide for eligible projects.
This supports Canada's strengthened climate plan, A Healthy Environment and a Healthy Economy. Canada is advancing projects that support the clean grid of the future and seize opportunities in the global electricity market to boost competitiveness. Collectively with investments from the Fall Economic Statement 2020 and Budget 2021, Canada will achieve our climate change commitments and ensure a healthier environment and more prosperous economy for future generations.
Spain Electricity Prices surge to record highs as the wholesale market hits €339.84/MWh, driven by gas costs and CO2 permits, impacting PVPC regulated tariffs, free-market contracts, and household energy bills, OMIE data show.
Key Points
Rates in Spain's wholesale market that shape PVPC tariffs and free-market bills, moving with gas prices and CO2 costs.
✅ Record €339.84/MWh; peak 20:00-21:00; low 04:00-05:00 (OMIE).
✅ PVPC users and free-market contracts face higher bills.
✅ Drivers: high gas prices and rising CO2 emission rights.
Electricity in Spain's wholesale market will rise in price once more as European electricity prices continue to surge. Once again, it will set a historical record in Spain, reaching €339.84/MWh. With this figure, it is already the fifth time that the threshold of €300 has been exceeded.
This new high is a 6.32 per cent increase on today’s average price of €319.63/MWh, which is also a historic record, while Germany's power prices nearly doubled over the past year. Monday’s energy price will make it 682.65 per cent higher than the corresponding date in 2020, when the average was €43.42.
According to data published by the Iberian Energy Market Operator (OMIE), Monday’s maximum will be between the hours of 8pm and 9pm, reaching €375/MWh, a pattern echoed by markets where Electric Ireland price hikes reflect wholesale volatility. The cheapest will be from 4am to 5am, at €267.99.
The prices of the ‘pool’ have a direct effect on the regulated tariff – PVPC – to which almost 11 million consumers in the country are connected, and serve as a reference for the other 17 million who have contracted their supply in the free market, where rolling back prices is proving difficult across Europe.
These spiraling prices in recent months, which have fueled EU energy inflation, are being blamed on high gas prices in the markets, and carbon dioxide (CO2) emission rights, both of which reached record highs this year.
According to an analysis by Facua-Consumidores en Acción, if the same rates were maintained for the rest of the month, the last invoice of the year would reach €134.45 for the average user. That would be 94.1 per cent above the €69.28 for December 2020, while U.S. residential electricity bills rose about 5% in 2022 after inflation adjustments.
The average user’s bill so far this year has increased by 15.1 per cent compared to 2018, as US electricity prices posted their largest jump in 41 years. Thus, compared to the €77.18 of three years ago, the average monthly bill now reaches €90.87 euros. However, the Government continues to insist that this year households will end up paying the same as in 2018.
As Ruben Sanchez, the general secretary of Facua commented, “The electricity bill for December would have to be negative for President Sanchez, and Minister Ribera, to fulfill their promise that this year consumers will pay the same as in 2018 once the CPI has been discounted”.
Global Electricity Demand Surge strains power markets, fuels price volatility, and boosts coal and gas generation as renewables lag, driving emissions, according to the IEA, with grids and clean energy investment crucial through 2024.
Key Points
A surge in power use that strained supply, raised prices, and drove power-sector CO2 emissions to record highs.
✅ 6% demand growth in 2021; largest absolute rise ever
✅ Coal up 9%; gas +2%; renewables +6% could not meet demand
✅ Prices doubled vs 2020; volatility hit EU, China, India
Global electricity demand surged above pre-pandemic levels in 2021, creating strains in major markets, pushing prices to unprecedented levels and driving the power sector’s emissions to a record high. Electricity is central to modern life and clean electricity is pivotal to energy transitions, but in the absence of faster structural change in the sector, rising demand over the next three years could result in additional market volatility and continued high emissions, according an IEA report released today.
Driven by the rapid economic rebound, and more extreme weather conditions than in 2020, including a colder than average winter, last year’s 6% rise in global electricity demand was the largest in percentage terms since 2010 when the world was recovering from the global financial crisis. In absolute terms, last year’s increase of over 1 500 terawatt-hours was the largest ever, according to the January 2022 edition of the IEA’s semi-annual Electricity Market Report.
The steep increase in demand outstripped the ability of sources of electricity supply to keep pace in some major markets, with shortages of natural gas and coal leading to volatile prices, demand destruction and negative effects on power generators, retailers and end users, notably in China, Europe and India. Around half of last year’s global growth in electricity demand took place in China, where demand grew by an estimated 10%, highlighting that Asia is set to use half of global electricity by 2025 according to the IEA. China and India suffered from power cuts at certain points in the second half of the year because of coal shortages.
“Sharp spikes in electricity prices in recent times have been causing hardship for many households and businesses around the world and risk becoming a driver of social and political tensions,” said IEA Executive Director Fatih Birol. “Policy makers should be taking action now to soften the impacts on the most vulnerable and to address the underlying causes. Higher investment in low-carbon energy technologies including renewables, energy efficiency and nuclear power – alongside an expansion of robust and smart electricity grids – can help us get out of today’s difficulties.”
The IEA’s price index for major wholesale electricity markets almost doubled compared with 2020 and was up 64% from the 2016-2020 average. In Europe, average wholesale electricity prices in the fourth quarter of 2021 were more than four times their 2015-2020 average, and wind and solar generated more electricity than gas in the EU during the year. Besides Europe, there were also sharp price increases in Japan and India, while they were more moderate in the United States where gas supplies were less perturbed.
Electricity produced from renewable sources grew by 6% in 2021, but it was not enough to keep up with galloping demand. Coal-fired generation grew by 9%, with soaring electricity and coal use serving more than half of the increase in demand and reaching a new all-time peak as high natural gas prices led to gas-to-coal switching. Gas-fired generation grew by 2%, while nuclear increased by 3.5%, almost reaching its 2019 levels. In total, carbon dioxide (CO2) emissions from power generation rose by 7%, also reaching a record high, after having declined the two previous years.
“Emissions from electricity need to decline by 55% by 2030 to meet our Net Zero Emissions by 2050 Scenario, but in the absence of major policy action from governments, those emissions are set to remain around the same level for the next three years,” said Dr Birol. “Not only does this highlight how far off track we currently are from a pathway to net zero emissions by 2050, but it also underscores the massive changes needed for the electricity sector to fulfil its critical role in decarbonising the broader energy system.”
For 2022-2024, the report anticipates electricity demand growing 2.7% a year on average, although the Covid-19 pandemic and high energy prices bring some uncertainty to this outlook. Renewables are set to grow by 8% per year on average, and low-emissions sources are expected to serve more than 90% of net demand growth during this period. We expect nuclear-based generation to grow by 1% annually during the same period.
As a consequence of slowing electricity demand growth and significant renewables additions, fossil fuel-based generation is expected to stagnate in the coming years, and renewables are set to surpass coal by 2025 with coal-fired generation falling slightly as phase-outs and declining competitiveness in the United States and Europe are balanced by growth in markets like China, where electricity demand trends remain a puzzle in recent analyses, and India. Gas-fired generation is seen growing by around 1% a year.
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.
