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Posts from the ‘Air transport’ Category

Commercial hybrid-electric aircraft, reduced carbon emissions

Science Daily, 25 March 2019

Although we’re still a long way from commercial airplanes powered by a combination of fossil fuel and batteries, a recent feasibility study at the University of Illinois explored fuel/battery configurations and the energy lifecycle to learn the tradeoffs needed to yield the greatest reductions in carbon dioxide emissions.

“In the energy supply chain there’s a phrase, from ‘well to wake.’ That is, fuel production begins at the oil well and ends at the wake of the airplane. Tracking costs and environmental implications across this entire lifecycle is important, because the implications for fuel and energy production can be substantially different, depending on the source. In this study, we looked at how technologies need to improve to make a hybridized configuration feasible, where feasibility is assessed based on a need to meet a certain range requirement and feature a large reduction in carbon emissions. The net carbon emissions were calculated from a combination of fuel burn and the carbon impact associated with recharging the batteries,” said Phillip Ansell, assistant professor in the Department of Aerospace Engineering in the College of Engineering at the U of I.

According to Ansell, that second part has been ignored.

“You can get a fuel burn reduction, but if the cleanliness of the electrical grid that’s being used to charge the battery system is not included, you’re missing a significant part of the carbon emissions total,” he said.

The study compared the relative CO2 emissions produced per kilowatt-hour for each individual state across the United States. It includes a map of the U.S. with values of how much carbon is produced per unit of energy.

But, to be commercially acceptable, a hybrid-electric aircraft needs to be able to carry the same number of passengers and travel the same distances as current all-fossil fuel aircraft do, so the study used the parameters for a single-aisle airplane that can carry approximately 140 passengers as a model. They parametrically varied the proportion of power across the propulsion driveshaft that was electrically derived, using configurations where 12.5 percent, 25 percent, or 50 percent of the necessary power was produced by an electric motor. The study didn’t consider cost in dollars, but rather the cost in CO2 emissions — the environmental cost.

The most feasible configuration from the model was a propulsion system that uses a 50 percent electrical-power drivetrain and a battery specific energy density of 1,000 watt-hours per kilogram. This configuration was estimated to produce 49.6 percent less lifecycle CO2 emissions than a modern conventional aircraft with a maximum range equivalent to that of the average of all global flights, making it a viable option for environmentally responsible aviation. However, current battery technologies are quite far from being able to achieve this configuration. Despite this fact, Ansell did say that improvements in batteries will continue to provide gains in capabilities.

“Obviously, the 12.5 percent is the most near-term accessible configuration that was studied, because we’ll need less battery technology progress to get to that point. However, we also see a non-linear relationship between CO2 emissions produced and improvements in hybrid-electric propulsion concepts, where the most rapid proportional reductions in carbon emissions are produced across near-term improvements in technology,” Ansell said. “Achieving the technology improvements for a 50% hybrid system certainly has a very long timetable to get to market, by a long shot, because it’s entirely uncertain if or when that level of energy density of batteries will be manufactured. But at least in the interim, even small gains in component technologies can make a big difference.”

When will technology be able to manufacture a battery lightweight enough yet powerful enough to fly a commercial airplane?

Ansell speculated, “Perhaps in the next 10 years we’ll be able to have a battery that is 400 to 600 watt-hours per kilogram. If we project that out, the levels that we need for larger hybridization factors, or even fully electric commercial aircraft, might be within reach in the next 25 years.”

https://www.sciencedaily.com/releases/2019/03/190325130524.htm

CCC warns without a ‘true zero-carbon plane’ demand for aviation may have to be curbed

Business Green, 14 February 2019

UK’s climate body confirms net zero target assessment will be published in May, stressing greater effort will be needed to cut aviation emissions

Adopting a net zero climate target in the UK would require greater effort to cut emissions from aviation, particularly through developing clean technologies and limiting growth in flight demand, the Committee on Climate Change (CCC) has told the government.

In a letter to the Transport Secretary Chris Grayling, CCC chairman Lord Deben stressed that limiting emissions from UK aviation would require contributions from all parts of the aviation sector, and that the government should avoid relying on biofuels or international carbon offset credits to do the necessary heavy lifting.

Deben welcomed the government’s commitment to keeping UK aviation emissions at 2005 levels by 2050, as advised by the CCC, and to ask the National Infrastructure Commission to scrutinise the case for further airport expansion with consideration of the potential climate impacts.

However, Deben reiterated the CCC’s view that the government should not plan for significant use of biofuels to power planes, due to uncertainty surrounding sustainable biomass supplies and costs.
Instead, he said the government and industry should focus on developing new low emission aircraft designs, improved air space management, and the use of more sustainable fuels in the coming years.

The letter also predicted brokering a long-term climate target for aviation at an international level would help incentivise investment in new, cleaner technologies, but emphasised technologies alone were unlikely to be enough to stem the climate impact of aviation.

“In the absence of a true zero-carbon plane, demand cannot continue to grow unfettered in the long-term,” the letter states.

Deben’s letter on Wednesday comes in response to the government’s Aviation 2050 strategy, which was launched for consultation in December. That draft strategy insisted the UK’s aviation sector could grow to meet rapidly increasing demand for air travel over the next three decades, while at the same time limiting emissions at 2005 levels by the middle of the century.

The strategy attracted criticism from green campaigners who highlighted the lack of detail on exactly how the government plans to limit the climate impact of growing demand for air travel over the next three decades.
Aviation is widely seen as one of the most challenging sectors of the economy to decarbonise, with emissions from the industry having more than doubled since 1990, in contrast to emissions for the economy as a whole having fallen by around 40 per cent.

The Department for Transport, however, has said it is currently developing a long-term policy framework with industry that will address how to ensure sustainable growth, and that it plans to update the aviation strategy at regular intervals. It has also pledged to work at an international level through ICAO to negotiate a long-term global goal for aviation emissions that would be consistent with the Paris Agreement.

The latest developments came as the CCC today confirmed its assessment of the UK’s potential to set a net zero emissions target for the middle of the century would be published on May 2nd 2019, conceding the publication date was “later than requested – a reflection of the scope and importance of the task”.

The UK currently has a legal requirement to achieve an 80 per cent cut in emissions by 2050 against a 1990 baseline, but the government last year asked the CCC to look at whether this should be replaced with a more ambitious goal.

In light of current work to develop both a UK aviation strategy as well as a potential net zero emissions target for the whole economy, CCC chief executive Chris Stark said there was therefore now a “clear opportunity” to clarify the role of aviation in the UK’s long-term climate ambitions.

However, campaigners remain sceptical about the government’s abilit to seize that opportunity. Grayling has faced fierce criticism over his support for aviation expansion and his limited engagement with climate change issues. When announcing the government’s backing for a third runway at Heathrow Airport last summer, the Transport Secretary made no mention of the potential impact the decision could have on the UK’s climate targets, prompting Lord Deben to express “surprise” in another letter from the CCC last year.

The CCC’s latest intervention will therefore ramp up pressure on the government to ensure its aviation ambitions come alongside robust plans to ensure any growth in UK airport capacity does not blow a hole in domestic carbon budgets.

The move also came ahead of Airbus’s shock announcement today that following a review of its operations it will stop making its huge A380 planes by 2021, potentially putting thousands of UK jobs at risk. The plane manufacturing giant said it was also reducing its A380 output in the meantime due to a lack of order backlog with airlines “and in light of developments in aircraft engine technologies”.

The move could have an important impact on emissions scenario planning for the UK and international aviation sector, commentators have pointed out. The huge A380 planes – first launched as a rival to Boeing’s 747s in 2007 – have four engines, while much of the sector has shifted over the past decade towards smaller, more fuel efficient aircraft.

With the CCC planning to publish its net zero emissions assessment in May, this week’s letter suggests the UK’s independent climate body is keen to ensure there is a robust long term plan in place to ensure sustainable growth of the domestic aviation sector in line with the UK’s carbon targets. The pressure is now on the government and aviation sector to set out in much more detail how it foresees an increase in flights in a net zero carbon world.

https://www.businessgreen.com/bg/news-analysis/3071084/ccc-greater-effort-from-aviation-required-for-net-zero-uk

Norway’s plan for for a fleet of electric planes

BBC News, 22 August 2018
By 2040, Norway has promised all of its short-haul flights will be on electric aircraft. It could revolutionise the airline industry.

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Airlines tackle Dreamliner nightmare

The West, 15 September 2018
Since late last year, airlines around the world have been dealing with problems with Rolls-Royce Trent 1000 Package C engines aboard some Boeing 787 Dreamliners. The engines have been affected by a “durability issue” in which compressor blades have been wearing prematurely. In June, it was reported that some older Package B engines were also affected.

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Flight times extended by major airlines to avoid payouts, report claims

The Guardian, 27 August 2018
Plane journeys are taking longer than a decade ago, according to a report that claims the change is down to airlines “padding” their schedules to create the impression passengers were reaching their destinations on time. Carriers are adding extra time to flight schedules, in some cases up to 30 minutes, to ensure they maintain punctuality and are therefore less likely to be liable for compensation payouts, the investigation by Which? Travel claimed.
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Singapore’s Wigetworks readies production-spec Airfish 8 WIG craft

Jane’s 360, 9 April 2018
Wigetworks, a Singapore-based firm specialising in wing-in-ground effect (WIG) technology research and development (R&D), is aiming to finalise the design of the production-ready version of its Airfish 8 (AF8) WIG craft prototype by the end of 2018 and is preparing to commence production when a launch customer is secured, company officials told Jane’s.
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Global pilot shortage hits Australia, with cancelled regional routes just the beginning

ABC News, 22 July 2018
Passengers are becoming used to flights being cancelled due to weather, or even volcanoes, but now a new trend is beginning to upset travel plans across the country. Airlines are having to cancel flights, and even entire routes, because there literally isn’t anyone available to fly the plane.
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First two retired A380 superjumbos to be broken up for parts

Traveller, 7 June 2018
Two of Airbus’s flagship A380 superjumbos are headed for the scrap heap after a search for new operators failed to secure firm bids.

Negotiations with British Airways, Iran Air and Hi Fly, a Portuguese charter specialist, ended without any deals, German investment fund Dr. Peters, which manages the planes, said in a statement to shareholders. The aircraft are already parked in the foothills of the French Pyrenees, where they will be filleted over the next two years by a specialist company and sold in parts.

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Reluctant Americans are behind Qantas’ quest to develop a cargo class

Sydney Morning Herald, 18 April 2018
Qantas’ “out there” idea to develop a new travel class in the cargo hold is aimed at getting middle-class Americans to shake off their reluctance to fly long-haul across the Pacific, Fairfax Media has learned. Last month, Fairfax Media revealed Qantas chief executive Alan Joyce had begun exploring a new “cargo class” concept which could be installed on super long-haul direct flights from Sydney to the US and London.
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Boeing raises prospect of only one pilot in the cockpit of planes

The Guardian, 9 February 2018
Once there were three on the flight deck. Then the number of flight crew fell to two when the Boeing 757 changed the way cockpits were designed in the 1980s. Now, jetmakers are studying what it would take to go down to a single pilot, starting with cargo flights.

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