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In today’s world, there is an increasing interest in individuals who are seeking different ways in which they can reduce their own personal contribution to climate change. While these changes may appear to be small, their potential impacts in reducing greenhouse gas emissions, as well as inspiring others to do the same, can lead to significant changes in the anticipated pattern of global warming. Some ways in which individuals can reduce their carbon footprint include reducing energy and water consumption, recycling as much as possible and utilization of both green and public transportation options.
Public transportation on its own offers various benefits for the environment as it eases congestion, reduces the production of harmful carbon dioxide (CO2) emissions and even significantly reduces transportation costs for the average household1. In fact, it is estimated that if a single individual, who typically commutes using their personal vehicle, switches to public transportation for their daily commute, their annual CO2 emissions can be reduced by a staggering 4,800 pounds per year1.
While the advantages of public transportation are clear in their ability to limit the amount of personal vehicles used each day, a number that is reportedly increasing each year. While public transit agencies have historically relied on diesel fuel to provide energy for their buses’ operation, their interest in continually providing the public with reliable and simultaneously innovatively clean technology for their vehicles remains.
Such clean and energy efficient alternatives to traditional public transportation vehicles include electric vehicles, diesel-electric hybrids, regenerative braking and energy storage within vehicles, use of biofuels, as well as hydrogen fuel cell vehicles2.
The earliest uses of diesel-electric hybrid buses took place during the late 1990s, however, only approximately 0.5% of transit buses were hybrids. By 2011, this statistic rose to approximately 17% of new hybrid buses being utilized by North American public transit agencies. One of the leaders of this transition to hybrid-electric buses is New York City, who currently runs a bus fleet of approximately 5,700 buses and 800 million rides per year, has worked towards adjusting their entire fleet to all electric buses, which they estimate will reduce the city’s greenhouse gas emissions by over 500,000 metric tons of CO2.
While the average cost of running a diesel bus can range from $450,000 to $750,000, electric bus operation averages at a cost of approximately $300,000. Additionally, by reducing the amount of particulate emissions that are released from diesel-fueled buses, the replacement of electric buses is also expected to reduce health care costs associated with heart and lung diseases that are often attributed to inhalation of harmful pollutants.
The incorporation of regenerative braking technologies into transit vehicles is an innovative energy storage mechanism that has been adapted to trains for several decades. These technologies, which capture and store the energy that is generated by the trains’ braking systems, acts as a feedback mechanism to continually provide power to trains within a given network. For example, Amtrak uses regenerative braking technology in approximately 80% of its fleet of electric trains, which allows electricity generated by the braking technologies to return to the power grid by traveling through overhead wires present above the trains2.
While this technology guarantees a way to ensure that all power is preserved and not lost, it is limited when the recovered power is not immediately used. Current research initiatives within the field of transportation has looked to developing regenerative braking technologies that return power to energy storage devices, such as batteries of supercapacitors, in order to ensure that the stored energy can be used at a more feasible convenience for the transit agencies’ purposes.
Transit agencies around the world remain to be innovative leaders in the incorporation of clean technology into their various types of vehicles’ operations. Encouragement by federal and state policies aimed at protecting the wellbeing of the public’s health, as well as the fate of the environment as a whole, has allowed for transit agencies to experiment and reap the benefits that are associated with applying such changes.
- “Public Transportation Reduces Greenhouse Gases and Conserves Energy” – American Public Transportation Association.
- “Transit on the Cutting Edge of Clean Technology” – American Public Transportation Association.