Sustainable Solutions
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collapse Topic : Commercial Transportation (1)
collapse Topic : Sustainability Background (1)
collapse Topic : Sustainable Solutions (7)
Product Lifecycle
Fuel Efficiency
Driving Behaviors
Alternative Fuel Sources
Public Transportation System
Land Use Planning
Long-term Change
collapse Topic : Transportation History (1)
collapse Topic : Transportation Issues (1)

​Alternative Fuel Sources

​Developments in alternative fuel source options may provide long term solutions to many of the problems that our reliance on transportation has caused.
  • ​Several alternatives to traditional gasoline and diesel fuel are in existence today, each having its own set of advantages and drawbacks.

First Generation Biofuels

  • Biodiesel is made from plant oils, typically soybean. It can be used in any diesel engine with little to no modification of the engine. Biodiesel reduces most greenhouse gas emissions, but concerns include:
  • Corn grain ethanol reduces greenhouse gas emissions and comes from corn, a plentiful crop in the United States. Corn grain ethanol also comes with concerns, which include:
  • Ethanol can also be generated from sugarcane stalks or sugar beets. However, it comes with similar concerns to corn grain ethanol, including cost, food shortages, and habitat destruction.

Second Generation Biofuels

  • Second generation biofuels are biofuels created from the “leftovers” of crop and forest harvesting as well as non-food crops. This eliminates the food shortage issue of corn grain ethanol and uses the plant more efficiently.
    • There are still issues with land use and clearing land area for crops, which can destroy carbon-sequestering ecosystems.

  • Cellulose is found in all plant material and may be utilized to manufacture biofuels.
    • This advanced cellulosic biofuel can be derived from agricultural waste and fast-growing switchgrass.
    • Advanced cellulosic biofuels, like other forms, reduces greenhouse gas emissions.
    • Production is not limited to regions where corn can be produced, and it does not require the same excessive use of fertilizers, pesticides, and energy and water to grow as traditional crops.
    • The refining process for advanced cellulosic biofuels is more complex than that of corn grain ethanol, but the resulting product has a higher energy yield. http://www.seco.cpa.state.tx.us/re_ethanol_cellulosic.htm 

Third Generation Biofuels

  • While still a highly experimental process, researchers are looking into the possibility of converting oil produced from the growth of algae into biodiesel, and then using the carbohydrate content for ethanol.
    • These fuels reduce greenhouse gas emissions, but growing the algae in high enough concentrations is complex and expensive.
    • It is possible for algae to double in volume overnight under the right conditions.
    • Algae production may also remove carbon from the atmosphere through photosynthesis. http://www.popularmechanics.com/science/energy/biofuel/4213775 

Electric

  • Using battery power does not result in any tailpipe emissions, and they are 99% cleaner than gasoline-powered vehicles. However, concerns with battery power include:
    • Recharging from conventional energy sources often results in using energy that was generated from power plants that emit high levels of greenhouse gasses and pollutants.
      • Approximately 90% of Wisconsin’s generating capacity comes from power plants that burn fossil fuels.
      • Using solar energy to recharge the battery can eliminate this issue.

  • Limited range and time to recharge

  • Proper manufacturing and disposal of the batteries themselves can be problematic. http://www.ucsusa.org/clean_vehicles/technologies_and_fuels/hybrid_fuelcell_and_electric_vehicles/battery-electric-vehicles.html 

Hydrogen

  • Hydrogen fuel cell vehicles run off of energy generated from the reaction between hydrogen and oxygen, with water being the only byproduct. When pure hydrogen is used, the result is zero fossil fuel use and zero greenhouse gas emissions.

  • We are currently only capable of producing hydrogen through a process that requires fossil fuels, which results in the production of greenhouse gasses.
    • If we can develop a way to utilize solar energy to produce hydrogen, then there will be zero greenhouse gas emissions.

  • Fuel cell vehicles are at this point primarily prototypes, and therefore current costs are high.

  • Fuel cells do not need to be plugged in, but need to be refueled more frequently than traditional gasoline vehicles. http://www.ucsusa.org/clean_vehicles/technologies_and_fuels/hybrid_fuelcell_and_electric_vehicles/fuel-cell-vehicles.html 

Hybrid Electric

  • Hybrid electric vehicles include an electric motor along with a combustion engine. This alleviates some of the concerns related to range and recharge time. However, hybrid electric vehicles still emit greenhouse gasses and have the same environmental concerns related to battery use.

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