User:Greenairplanes/Green airplanes

Green Airplanes
 * A green airplanes or environmentally friendly airplane is any type of aircraft, whether commercial or private, which has less negative effect on the environment than the current basic passenger and cargo jets that have gone several decades without major changes in design or efficiency. The term is used to describe any aircraft that has taken the expensive gamble of redesigning the aerodynamic features of the plane as well as increasing engine efficiency to decrease fuel consumption and environmental impact.


 * Green airplanes can have one, or several improvements which can limit their negative ecological effect. Improvements may include fixing plane design to decrease drag, using new fuel efficient engines, using biofuels, improving the routes flown, or using lighter materials to build the planes. Although there are a few smaller aircraft being invented to fly on electric and solar based power sources, most green airplanes are using more fuel efficient processes and technologies to achieve cost-effective solutions to decrease fuel consumption and their carbon emissions.

Basic overview
Aircraft systems convert fuel energy to mechanical energy and accomplish the goal of moving people and cargo from place to place. Unfortunately this fuel energy conversion creates carbon dioxide, nitrous oxides, particles, and other greenhouse gases which contribute to the global warming phenomenon. Some facts about aircraft:
 * Globally, world’s 16,000 commercial jet aircraft generate more than 600 million tons of carbon dioxide per year.41
 * Commercial aircraft is second only to highway vehicles as consumers of motor fuels42
 * Demand for aircraft is growing twice as fast as demand for highway vehicles24
 * Fuel is the second highest expense for airlines after labor38
 * Air traffic is expected to double in the US by 2017 and internationally by 2010 according to Federal Aviation Administration43
 * 32 of 50 biggest US airports have current plans to expand43
 * Automobiles have undergone extensive design change over last half-century23
 * Aircraft design has remained generally the same over the same time period


 * Retrofitting old aircraft is very expensive39
 * Sustainable aircraft is increasingly tougher to create because of a 57% decline in aerospace engineers since 199024
 * As bad as airplane efficiency is, it is 15% more efficient than train transport28
 * Travel emissions are not regulated under the Kyoto Protocol43
 * The International Air Transport Association (IATA) has set goal of creating a zero emission plane in 50 years22
 * European Union plans to have an emissions cap and trading system on airlines by 201222
 * MIT made green airplane using 70% less fuel than current planes23
 * Reduces noise, carbon output, and nitrous oxide output
 * Funded by NASA

The technology is available but barriers remain. Airplanes continue to pollute at a rate well above 600 million tons of carbon dioxide a year. The current green airplanes of today use 70% less fuel, produce 75% less nitrous oxides, and require less real estate and air space for takeoffs and landings.23 But even these standards can be improved. So far airlines have been unwilling to retrofit aging, fuel inefficient airplanes and governments have yet to adopt a tax on air travel or come up with an emissions trading program.

Inefficiencies and Pollution
At its’ current rate of use the airline industry contribute over 3% to the world’s greenhouse gas pollution. Aviation emissions increased 87% between 1990 and 2006 and demand is growing.17 The lack of efficient, green airplanes on the assembly line adds to the uncertainty of the future impact airplanes may have on the environment as demand increases over the next 40 years. Some scenarios anticipate aircraft will contribute up to 15% of global greenhouse gas emissions by 2050.17 Some of the products of inefficient airplanes are as follow:


 * Carbon dioxide -the main byproduct of combustion engines and leading contributor to global warming. Airplanes contribute 2% to rising CO2 levels17
 * Nitrous oxides – nitric oxide and nitrogen dioxide combine to form nitrous oxides. These oxides help form O3, ozone in the upper troposphere which furthers the effect of global warming. Whereas carbon dioxide has the same effect no matter where it is released, nitrous oxides potent, global warming effects are compounded the higher in elevation they are released30. Over the short term, they more than double the effects of CO2 alone.30 One airplane taking off and landing from JFK airport in the mid 1990s would have produced as much nitrous oxide as a car driven 26,500 miles.30
 * Water vapor – product of burning hydrocarbons. This greenhouse gas forms contrails which are easily seen trailing planes. These contrails commonly form artificial clouds which contribute to the global warming effect.
 * Carbon monoxide – bonds with oxygen to form carbon dioxide immediately upon release
 * Hydrocarbons – combine with nitrous oxides and sunlight to contribute to the formation of the tropospheric ozone and greenhouse gases.
 * Particulates - tiny subdivisions of solid or liquid matter suspended in a gas or liquid. These particulates, or soot, scatter and absorb solar and infrared radiation in the atmosphere and contribute to global warming.
 * Noise pollution – the noise from airplanes can have negative health and social effects on people35

All of these factors combine to attribute to the growing levels of greenhouse gases in the atmosphere. Although aircraft pollution does not contribute as much greenhouse gases into the environment as highway vehicles, its effects are multiplied due to the proximity of the aircraft to the fragile ozone layer. Flying near the stratosphere exponentially increases the total impact of man-made climate change.17 Consider these facts:
 * Air travel destroys good ozone which is necessary to protect humans from ultraviolet radiation produced by the sun. This also includes flights by military supersonic jets that consume more fuel than commercial airliners.30 These jets fly in the stratosphere and further damage the ozone.
 * Air travel creates pollution in the troposphere where most commercial planes fly. This pollution then becomes ozone in the upper troposphere and is a potent climate-changing greenhouse gas.30

Energy Efficiency
An automobile’s fuel efficiency is based on the average miles per gallon on a highway as well as in a city. This number is easily transparent and available for anyone looking to buy a car. An airplane’s fuel efficiency is less transparent in that there are many variables that contribute to its’ degree of efficiency. Some of the few variables include speed of the plane, weight load, and wind speed. Green aircraft seek to cut down on the inefficient makeup of a plane as well as inefficient flight techniques.

Weight load

 * The main goal is to reduce drag, which must be opposed to thrust for an airplane to progress. Drag is proportional to the lift required for flight, which is equal to the weight of the aircraft.15 Mass reduction is a principal source of efficiency gains in aircraft. Carbon fiber is as a very light building material and is being used to in place of aluminum. Making wings out of carbon fiber decreases fuel consumption up to 20%. The carbon fiber is both lighter and more durable and can make for enormous fuel efficiencies. Heavy structures and big planes mean planes have to carry a lot of fuel. The additional fuel needed contributes to an even heavier plane and more fuel consumption39. Reducing the weight of the structure of the plane will require less fuel with the rule-of-thumb being that a 1% weight reduction corresponds to around a .75% reduction in fuel consumption.15 With 30% of aviation costs being fuel39, reducing weight load can decrease emissions as well as decrease costs.

Advanced airframe configuration

 * Wide body planes are not necessarily more fuel efficient than narrow body planes.39 The use of skinner wings and smaller tails helps reduce the drag and amount of fuel needed.23 Winglets are a vertical extension of the wing tips. Their intended effect is always to reduce the aircraft's drag by altering the airflow near the wingtips. This painless modification to the end of each wing converts some of the other-wise wasted energy from a process known as wingtip vortex, and turns it into a thrust. They can improve fuel economy up to 7%.20

Energy efficient engines

 * Energy efficiency of jet engines installed in vehicles has two main components:21
 * Cycle efficiency - how efficiently the engine can accelerate the jet
 * Propulsive efficiency - how much of the energy of the jet ends up in the vehicle body rather than being carried away as kinetic energy of the jet.

Biofuels

 * Virgin Atlantic leads the way in alternative energy for aviation. In 2006 Virgin Atlantic used all its profits for research and development of alternative fuels. They currently use 80% jet fuel and 20% biofuel22
 * The drawback of biofuels is that require increased land use and put pressures on food prices and may increase greenhouse gas emission just to produce them.

Air traffic controls

 * More direct routes will cut down on unnecessary fuel use
 * Less layovers and more direct flights since aircraft burn the most fuel during the climb and descents39
 * Slower speeds which help increases gas mileage

Fuller capacity

 * 20% of flights are not at full capacity. Planes that do not fill up can be considered more environmentally unsustainable since carbon dioxide emissions increase per passenger. Max loads increase efficiencies as the weight of passengers is negligible when compared to weight of cargo and the plane structure
 * U.S. airplanes averaged 64 mpg in 2009.37 Miles per gallon for airplanes is calculated by how far one seat, regardless of whether it is occupied or not, can travel on one gallon of gas.

Revive or replace old planes

 * Oldest airplanes are the most inefficient. New planes are already 70% more efficient than they were 40 years ago and 20% better than they were 10 years ago.39 Between 1960 and 2000 there was a 55% overall fuel efficiency gain. Currently, old planes that are replaced by more efficient ones are simply sold to other airlines, usually in poor, developing countries. Instead of retiring the inefficient planes they are simply moved to another part of the world.

Increase price of flights

 * A 10% increase in fares will equal a 5% to 15% reduction in demand. An increase in price may help alleviate any unneeded leisure travel that cheap airfare promotes.

Tax on air travel and a global emissions trading system

 * Aviation is untaxed, meaning it has a huge economic advantage over driving.39 A tax on airfares would level the playing field and correct the price of flights to match the true market and ecological value, so far neither has been enacted.

Types of Sustainable Airplanes
Green airplanes include aircraft types that function fully or partly on alternative energy sources other than conventional combustion engines powered by fossil fuels. Another option is the use of fuel-less flight.

Electric Airplanes:
An electric aircraft is an aircraft that runs on electric motors rather than internal combustion engines, with electricity coming from fuel cells, solar cells, ultracapacitors, power beaming,[1] and/or batteries.47

Solar Powered Airplanes:
Solar powered airplanes are vehicles that are powered by solar energy obtained from solar panels on the surface of the aircraft. Photovoltaic (PV) cells convert the Sun's energy directly into electrical energy. The first solar powered airplane took flight in the early 1970s and ever since research and development has gone into improving the idea of sun powered flight. NASA has had the most success in development in solar powered aircraft with their Helios Prototype which sustained flight for 15 hours50 and set a new record world altitude record for propeller-driven aircraft of almost 97,000 feet.48 The “Hy-Bird” project with Solar Impulse has set a goal to fly around the world in a solar airplane.49

Hybrid Airplanes:
There are a variety of hybrid aircraft technologies. A Hybrid Aircraft combines the characteristics of a fixed wing aircraft with lighter than air technologies.[|51] Hybrid Aircraft use the advantages of aerodynamic lift derived from the lifting-body hull shape, as found in an airplane, and efficiencies of lighter-than-air derived from the buoyancy of the helium filled envelope, like an airship.52 NASA and Boeing have been working together to develop plans for a hydrogen-powered jet airplane. They hope to reform Jet-A fuel into hydrogen creating a more electric airplane. This would reduce airport emissions using solid oxide fuel cells. They plan to have the first hydrogen fuel cell commercial airplane ready in 2015.53

Gravity Powered Aircraft:
Gravity powered aircraft combine the technology of a glider and aerostatic lift. The aircraft uses helium filled compartments to float off the ground.54 The aircraft uses buoyancy principles to float up to an altitude where the helium is no longer lighter than the air that surrounds the aircraft. At this point gravity begins to pull the aircraft back to the ground where its glider technology comes into play. As the plane loses altitude the helium once again becomes more buoyant than the surrounding air causing the aircraft to rise again. This cycle repeats itself until the onboard pumps empty the helium chambers allowing the aircraft to glide back to earth for its landing.55 This gravity powered aircraft technology was developed by Robert D. Hunt.54

Carbon Standards
The International Civil Aviation Organization (ICAO)46 has drafted a timetable for developing a global carbon dioxide standard for new aircraft types, among other recommendations from the organization’s committee on aviation environmental protection. The organization has created a CO2 standard they want to be implemented by 2013. The first stage of the plan is to have 15% stronger nitrogen oxides standards for new aircraft engines made after December of 2013. The ultimate goal is to have a 2% annual improvement in fuel efficiency globally until 205045

Environmental:
An Aviation and Global Climate Change study, from the UK-based Friends of the Earth, found air travel to be the world’s fastest growing source of greenhouse gas emissions. Their study indicates the world’s 16,000 commercial jet aircraft generate more than 600 million tons of carbon dioxide (CO2) each year.1 Currently air travel accounts for 3.5% of global warming by human activities.2 By 2050 Air travel could account for as much as 15% of the total green houses emissions produced by humans.3 The European Commission reports that greenhouse emissions could increase by 150% by 2012.3 Nitrogen oxides (NOx) and water vapor have a more significant effect on the climate when emitted at altitude than at ground level. Therefore any strategy to reduce aircraft emissions will need to consider all greenhouse gases and not just CO2 alone.2 Aircraft vapor trails or contrails, can lead to the formation of cirrus clouds in the atmosphere. Contrails and cirrus clouds warm the earth’s surface magnifying the global warming effect of aviation. The exhaust from aircraft engines is made up of: 7% to 8% CO2 and water vapor; 0.5% nitrogen oxides, unburned hydrocarbons, carbon monoxide and sulphur oxides; traces of hydroxyl family and nitrogen compounds and small amounts of soot particles (although the industry has managed to more or less eliminate soot emissions over the past few decades). Between 91.5% and 92.5% of aircraft engine exhaust is normal atmospheric oxygen and nitrogen.4

Health:
Airtravel has been linked to human health issues including, noise pollution and air pollution.1 These pollutants cause human health issues such as respiratory problems, cardiopulmonary disease and lung cancer. A 1998 report estimated that up to 24,000 people die prematurely each year in the UK as a direct result of air pollution.5 According to the World Health Organisation, up to 13,000 deaths per year among children age 0–4 years across Europe are directly attributable to outdoor pollution. The WTO estimates that if pollution levels were returned to within EU limits, more than 5,000 of these lives could be saved each year. There is recent evidence to show that areas around airports can be as polluted as some major city centers.1

Boeing:
Boeing recognizes the serious challenges facing our eco-system and is committed to improving the environmental performance of its operations, products and services. Our greatest contribution to meeting the challenge is to pioneer new technologies for environmentally progressive products and services -- and to design, develop and build them in an environmentally responsible manner.6 Some of Boeings policies include; pioneer new technology to improve global air travel, improve research to improve efficiencies, reduce CO2 emissions by 15% for each new generation of air craft.7 Boeing set the following goals to be completed between 2007-2012:8


 * 25 percent reduction in greenhouse gas emissions (on a revenue-adjusted basis).
 * 25 percent reduction in energy consumption (on a revenue-adjusted basis).
 * 25 percent reduction in water consumption (on a revenue-adjusted basis).
 * 25 percent reduction in hazardous waste generation (on a revenue-adjusted basis).
 * 25 percent improvement in solid waste recycling rates (on a total or "absolute" basis).

Airbus:
Over the courseSuperscript text of its 40-year history, Airbus has put the highest priority on environmental performance. From the beginning, the company has adhered to its philosophy of increasing the number of passengers (or amount of freight) per flight, while reducing overall energy consumption and perceived noise. With this goal in mind, Airbus has contributed significantly to the aviation industry’s improved eco-efficiency over the past decades. The pioneering A320 – which Airbus introduced in 1988 – provides the lowest fuel burn per trip of any single aisle aircraft with more than 100 seats, and its 21st century flagship A380 has a relative fuel efficiency of 2.9 litres. Airbus aircraft show significant progress in eco-efficiency across the board when compared to aircraft from the 1970s, including a 20-decibel decrease in noise with 75 per cent less noise annoyance. Air quality also has been drastically improved with a 90 per cent reduction in unburned hydrocarbon (HC) and smoke emissions, and a more than 50 per cent reduction in carbon monoxide.9 Airbus to date has accomplished the following goals in their environmental efforts.10 The following goals have been set by Airbus to be completed by 2020.11
 * ISO 14001 certified: certified facilities ensures the entire aircraft manufacturing process meets increasingly strict environmental standards.
 * Practices “eco-efficiency” by making their nearly 3000 suppliers more ecologically efficient from production to disassembly.
 * Airbus recycles or reuses 80-85% of a decommissioned aircraft.
 * 30% reduction in energy comsumption
 * 50% reduction in CO2 emmisions
 * 50% reduction in water consumption
 * 80% reduction in waste production
 * Minimize disturbance levels
 * Respect landscape and biodiversity
 * Limit the impact of oversize transport activities

Design Competition for New Aircraft
NASA 2.1 million dollar competition. Their objective was to develop concepts for, and evaluate the potential of, quieter subsonic commercial planes that would burn 70 percent less fuel and emit 75 percent less NOx than today’s commercial planes. NASA also wanted an aircraft that could take off from shorter runways. Participating companies and Universities included, MIT, Boeing, GE Aviation, and Northrop Gumman.12 Airbus recently unveiled its second global student contest. Each submission is to be viewed for its contribution to the ‘Environmental Life Cycle’ – an innovative approach Airbus uses to improve the environmental performance of an aircraft and its production process. Submissions must have ideas for five stages: design; supply chain; manufacturing; aircraft operations and aircraft end-of-life.11 Another competition run by NASA in cooperation with the CAFE (Comparative Aircraft Flight Efficiency) Foundation – has been named the Green Flight Challenge, and its aim is to find a new enviro-aircraft design based on the following credentials, the aircraft must be able to fly at an average speed of 100 miles an hour over a distance of 200 miles and the aircraft’s performance must not fall below 200 miles per gallon.13

Online Sources

 * 1) http://www.foe.co.uk/resource/reports/aviation_climate_change.pdf
 * 2) http://www.ipcc.ch/index.htm
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 * 4) http://www.enviro.aero/aviationsroleinclimatechange.aspx
 * 5) http://www.dh.gov.uk/ab/comeap/index.htm
 * 6) http://www.boeing.com/aboutus/environment/
 * 7) http://www.boeing.com/aboutus/environment/policies.html
 * 8) http://www.boeing.com/aboutus/environment/measures.html
 * 9) http://www.airbus.com/en/corporate/ethics/environment/vision/
 * 10) http://www.airbus.com/en/corporate/ethics/environment/eco-efficiency/
 * 11) http://www.energyboom.com/transportation/airbus-launches-2010-fyi-contest-green-aviation-industry
 * 12) http://web.mit.edu/press/2010/green-airplanes.html
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 * 14) http://www.enviro-news.com/news/nasa_challenge_encourages_new_green_aircraft_designs.html
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 * 19) http://en.wikipedia.org/wiki/Pollution
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 * 21) http://en.wikipedia.org/wiki/Jet_engine
 * 22) http://www.seatguru.com/articles/green_aircraft_and_airlines.php
 * 23) http://web.mit.edu/press/2010/green-airplanes.html
 * 24) http://news.cnet.com/8301-11128_3-9931580-54.html
 * 25) http://www.energyboom.com/transportation/airbus-launches-2010-fyi-contest-green-aviation-industry
 * 26) http://www.foxnews.com/story/0,2933,572708,00.html
 * 27) http://www.science20.com/news_articles/sharks_inspire_energy_efficient_airplanes
 * 28) http://www.lafn.org/~dave/trans/energy/rail_vs_airEE.html
 * 29) http://www.transportenvironment.org/News/2009/12/Aircraft-energy-efficiency-has-not-improved-in-a-decade/
 * 30) http://www.sightline.org/research/energy/res_pubs/rel_air_travel_aug04
 * 31) http://www.boeing.com/commercial/aeromagazine/articles/qtr_4_07/article_02_1.html
 * 32) http://www.wired.com/autopia/2009/12/boeing-787-dreamliner/
 * 33) http://nextbigfuture.com/2009/07/future-fuel-efficient-airplanes.html
 * 34) http://www.enviro.aero/Default.aspx
 * 35) http://ehp.niehs.nih.gov/qa/105-12focus/focus.html
 * 36) http://www.smartertravel.com/travel-advice/minimize-the-environmental-impact-of-your-air-travel.html?id=2533153
 * 37) http://online.wsj.com/article/SB10001424052748704901104575423261677748380.html?mod=WSJ_hpp_RIGHTTopCarousel_1
 * 38) http://www.globalchange.com/aviation-fuel-efficiency-and-climate-change.htm
 * 39) http://www.switched.com/2008/06/30/airbus-unveils-carbon-fiber-plane/
 * 40) http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840021807_1984021807.pdf
 * 41) http://observer.guardian.co.uk/carbontrust/story/0,16099,1511925,00.html
 * 42) http://www.annualreviews.org/doi/pdf/10.1146/annurev.eg.17.110192.002541
 * 43) www.acac.org.ma/SEMINAIRES/Sem20-12-05Damas/5.ppt
 * 44) http://www.thedailygreen.com/environmental-news/latest/green-plane-travel-tips-0525