Environmental design Environmental design is the process of addressing surrounding environmental parameters when devising plans, programs, policies, buildings, or products. It seeks to create spaces that will enhance the natural, social, cultural and physical environm ...

is an emerging topic in

railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a prep ...

technology. From the 1980s to 2009,

fuel efficiency Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device ...

in diesel locomotives in the USA has increased 85%, allowing these trains to go farther and move more freight while using less fuel. New low-impact

electric Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by ...

and hybrid trains reduce overall carbon emissions. Also, train manufacturers have started utilizing hydrogen technology for propulsion, with carbon emissions only coming from the manufacturing of the hydrogen itself.

Increasing efficiency while lowering emissions

Diesel trains

Diesel trains replaced the steam engine in the late 1920s as a cleaner more efficient way of moving people and goods. Since 1980, the amount of freight being hauled by Diesel Trains has nearly doubled, yet the fuel consumption of trains has virtually stayed the same. Estimates have shown that about of fuel have been saved by increasing the efficiency in diesel trains. US Department of Energy reported that commercial airline energy intensity was , automobiles were , while commuter rail energy intensity was just , which indicates that rail transportation is the most energy efficient of the three. The Union Pacific Rail Road has implemented a particle filter on their diesel engines. Silicon carbide blocks trap particles from the exhaust as they leave the engine, greatly reducing emissions.

Electric trains

Electric trains have always had no direct carbon emissions because they are run entirely by internal electric motors. However, the means of generating the electricity used to power these motors was predominately by burning fossil fuels or coal, both of which produce a large amount of carbon emissions. With the emergence of 'clean energy' generation, electrical trains actually run with very low environmental impact. For example, the proposal for the high-speed rail line between

San Francisco San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17t ...

and

Los Angeles Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

has the potential for zero

greenhouse gas emissions Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and ...

, with the 3,350 GWh each year being generated by California's extensive infrastructure of renewable energy sources.

Hybrid trains

Since 1986, engineers have been developing electric-diesel "hybrid" trains. One type of hybrid train implements battery power when the train is idling and at low speed movement, and a diesel engine at higher speeds. To recharge the batteries, power from the diesel motor, charge utilizing

regenerative braking Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction mo ...

, or a combination of both is used. According to the

Institute of Electrical and Electronics Engineers The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...

, hybrid trains reduce the carbon emissions of Diesel Trains by 19%. Another type of hybrid train, such as the

RailPower Technologies Railpower Technologies is a subsidiary of R.J. Corman Railroad Group that builds environmentally friendly hybrid Green Goat and Genset switching locomotives, founded by Frank Donnelly and Gerard Koldyk. Its locomotives have been purchased by ...

Green Goat, uses a large battery, and a small set of generators ("genset") for power. The genset is run at a constant speed and is attached to a generator to replenish the battery.

Hydrail

Hydrogen propulsion is an emerging technology, and is currently being implemented in locomotives. Hydrogen-powered trains dubbed "

Hydrail In transportation, hydrail is the generic term describing all forms of rail vehicles, large or small, which use on-board hydrogen fuel as a source of energy to power the traction motors, or the auxiliaries, or both. Hydrail vehicles use the chem ...

" emit only water as a by product of combustion, and have a zero direct greenhouse gas emission. However, the process used to generate hydrogen in a form useful to power trains does produce a small amount of greenhouse gases. By using wind energy and electrolysis, 6.85 grams of greenhouse gases per MJ of LHV are produced, which is an insignificant amount compared to the 22 pounds of greenhouse gas emissions from one gallon of gasoline. Trains are prime targets for hydrogen propulsion due to their ability to store massive tanks of hydrogen.

Emissions comparison

Rail transportation emits about 0.2 pounds of greenhouse gases per passenger mile (55 g/km) when each car is filled with 50 passengers. This figure increases to about 0.5 pounds per passenger mile (140 g/km) when only filled with half that amount. These numbers are still much lower than those of Jet transportation, about 1 pound per passenger mile (280 g/km), and that of a solo car driver, about 1.15 pounds per passenger mile (325 g/km). Even the fuel efficient

Prius The is a car built by Toyota which has a hybrid drivetrain, combining an internal combustion engine with an electric motor. Initially offered as a four-door sedan, it has been produced only as a five-door liftback since 2003. In 2007, th ...

emits more greenhouse gases per passenger mile. Estimates have shown that if just 10% of long-distance freight that is currently moving by truck were to be moved instead by diesel trains, the resulting carbon emission reduction would be the equivalent of taking 2 million cars off the road. The results are more dramatic when the diesel train figures are replaced by hybrid and electric train figures.

References

External links

* * * {{DEFAULTSORT:Environmental Design In Rail Transportation Rail technologies Sustainable transport