Future of the School Bus


Grade Level & Subject: Grades 9-12: Economics

Length: 1 class period


After completing this lesson, students will be able to:

  • Understand what algae biodiesel is and how it works.
  • Evaluate whether algae biodiesel would be an economically viable choice for their community even if it is more expensive than conventional diesel.
  • Think critically about different ways school buses could be improved for future generations.

National Standards Addressed:

This lesson addresses the following National Education Standards:[1]

As a result of activities in grades 9-12, all students should develop understanding of:

  • Choices made by individuals, firms, or government officials often have long run unintended consequences that can partially or entirely offset the initial effects of the decision.
  • Content Standard: NSS-EC.9-12.2 MARGINAL COST/BENEFIT

As a result of activities in grades 9-12, all students should develop understanding of:

As a result of activities in grades 9-12, all students should develop understanding of:

  • Comparing the benefits and costs of different allocation methods in order to choose the method that is most appropriate for some specific problem can result in more effective allocations and a more effective overall allocation system.

Materials Needed:

  • Projector (optional)
  • Reproducible #1 – Algae Biodiesel
  • Reproducible #2 – Converting Your Town

Students will be assessed through the following activities:

  • Completion of Reproducible #2 – Converting Your Town.
  • Participation in class discussions.



Relevant Vocabulary:

  • Biodiesel:A clean-burning, non-toxic, non-petroleum based fuel that is produced from any vegetable oil or animal fat. Biodiesel dramatically reduces air pollution and is less hazardous to human health.[2]
  • Biofuel:A fuel (as wood or ethanol) composed of or produced from biological raw materials.[3]
  • Diesel:A heavy mineral oil used as fuel in diesel engines.[4] Diesel exhaust contains particulate matter (small particles) that can be very harmful to human health, causing lung damage and aggravating asthma and bronchitis.[5]

Background Information:

Biodieselis a form of diesel fuel that is created from vegetable oils, animal fats, or even recycled grease from kitchens. Biodiesel is a great alternative to regular diesel because it is completely renewable, creates 78% less carbon dioxide emissions, and it can be grown domestically which not only would help the U.S. economy, but would allow the country to become less dependant on foreign fuel sources.[6]

Though scientists began toying with the idea of algae as biofuel in the 1970s, algae biodiesel has only recently become a contender for cleaner, renewable energy. In 2010, the Navy bought over 20,000 gallons of biodiesel for use in jet planes, and companies are hoping that in the next few years, algae biodiesel will be available to the public.[7] Since algae biodiesel will work in regular diesel engines, switching to this source would be relatively easy. Today, algae biodiesel is more expensive than conventional diesel and other biodiesels, but researchers and companies are working hard to find new ways to lower costs. Since biodiesel is better for the environment, in the long run it makes more economic sense to spend a little extra money now rather than a great amount later to fix the problems we have created.



  • National Algal Biofuels Technology RoadmapU.S.Department of Energy:




Warm-up: What Are Buses Like Today?

  1. Ask the class following questions:
  2. How many students in America do you think ride the bus every day? 24 million students.[8]
  3. Why are school buses important? Answers will vary, but ensure that students understand that without school buses, students would need to be driven to school which would result in the use of more fossil fuels, or students would have difficulty getting to school at all. School buses are vital to the education system.
  4. How many miles per gallon does your car at home get? Answers will vary, but if students do not know, explain that the average mpg of passenger cars is about 23.[9]
  5. How many miles per gallon do you think school buses get? 7 miles per gallon on average.[10]
  6. What are some other problems with school buses? Answers will vary, but may include: too crowded; uncomfortable; smell bad; emit CO2 and carbon monoxide; idle and waste fuel; etc.
  7. What do you think school buses will be like in 20 years? What about in 50 years? Answers will vary.

Activity One: Algae Biodiesel

  1. Explain to students that our oil supply is limited, and we must find other ways to fuel our vehicles. Ask students if they know of any other ways of powering our vehicles. Answers will vary, but may include: ethanol, biodiesel, hydrogen, electricity, natural gas, algae. Hand out or show on a projector Reproducible #1 – Algae Biodiesel and have students read out loud or individually.
  2. Hand out Reproducible #2: Converting Your Town and explain to students that they will assess the benefits of algae biodiesel in the future, since algae biodiesel is not yet being used in the public. Have students complete worksheet on their own, and collect it when they have finished.
  3. Once students have finished, lead a discussion about their findings:
  4. Is algae biodiesel a good choice?
  5. How will this affect the economics of the town: will jobs be lost or gained?
  6. Do you see this happening in the future?

Wrap Up: Economics

  1. Ask students to tie this lesson into economics with the following questions:
  2. Right now, algae biodiesel is more expensive than conventional diesel. Would it still make economic sense to use a more expensive fuel? Possibly, because the damage that CO2 and CO do in the long run could require a large amount of money and resources to fix in the future. Therefore, spending extra money today may save money in the future.
  3. What would switching from diesel to biodiesel do to your town economically? Would jobs be lost or gained? Or will it have no effect? Answers will vary: algae biodiesel opens up job opportunities for scientists, researchers, and entrepreneurs that set up algae farms or factories. However, moving away from conventional diesel could also result in a loss of some jobs.

Extension Activities:

  1. Have students research different algae biodiesel companies to explore the innovative ways that they each create their algae biodiesel. Some companies to look at are Solazyme,[11] Solix,[12] and Kai Bioenergy,[13] but there are many others as well.



At the end of this lesson, students will have learned about algae biodiesel and its benefits and drawbacks. Students looked at the economic aspects of switching to algae biodiesel in their own towns, and considered its environmental impacts as well. Students were able to come up with different ways that school buses might be improved for the future.



Katie Alexander – Author

            Education Intern, Earth Day Network

Josh Volinsky – Editor

            Green Schools Coordinator, Earth Day Network

[2]“Emission Controls and Bio-Diesel to Reduce School-Bus Pollution.” Department of Ecology. Retrieved 1 April 2011 from http://www.ecy.wa.gov/news/2003news/2003-214.html.

[3]“Biofuel.” Merriam-Webster Online Dictionary. Retrieved 8 April 2011 from http://www.merriam-webster.com/dictionary/biofuel?show=0&t=1302275916.

[4]“Diesel Fuel.” Merriam-Webster Online Dictionary. Retrieved 8 April 2011 from http://www.merriam-webster.com/dictionary/diesel%20fuel

[5]“Human Health.” Environmental Protection Agency. Retrieved 1 April 2011 from http://epa.gov/cleanschoolbus/humanhealth.htm.

[6]“Just the Basics: Biodiesel.” U.S.Department of Energy. Retrieved 8 April 2011 from http://www1.eere.energy.gov/vehiclesandfuels/pdfs/basics/jtb_biodiesel.pdf.

[7]Graff, Stephen. “Solazyme Developing Cheaper Algae Biofuels, Brings Jobs to Pennsylvania.” Department of Energy Blog. 6 August 2010. Retrieved 1 April 2011 from http://blog.energy.gov/blog/2010/08/06/solazyme-developing-cheaper-algae-biofuels-brings-jobs-pennsylvania.

[8]“Clean School Bus Program.” Environmental Protection Agency. Retrieved 1 April 2011 fromhttp://www.epa.gov/cleanschoolbus/.

[9]“Average Fuel Efficiency of U.S. Passenger Cars and Light Trucks.” Bureau of Transportation Statistics. Retrieved 8 April 2011 from http://www.bts.gov/publications/national_transportation_statistics/html/table_04_23.html.

[10]Laughlin, Michael. “Analysis of U.S. School Bus Populations and Alternative Fuel Potential.” U.S.Department of Energy. April 2004. Retrieved 1 April 2011 from http://www.nrel.gov/docs/fy04osti/35765.pdf.