Can you answer these questions?

•  What is a payback ratio?
•  What programs are available for consumers wanting to purchase green energy?
•  What are some things YOU can do to contribute to a sustainable future?

Join us on the field trip to find out!

Societies, governments, businesses, and individuals have to make decisions as to which energy source best fits and is most appropriate for their needs. As seen in these Renewable Energy Virtual Field Trips there are advantages and disadvantages to all renewable energy resources. No one renewable energy type will totally replace fossil fuel use; however, the use of a variety of sources provides a measure of security against total grid disruption should any one energy source fail (L.T. Goodlife Publishing Company, Inc. 2004). Educated decisions between renewable energy types and between renewable and non-renewable energies can be made by comparing costs, payback ratios, and environmental impacts. Furthermore, what is most clear to some researchers and educators is that in order to progress toward a sustainable world there has to be a change in paradigm, a change in the way people — a change in the way YOU — view the world and the future. Your actions today, the energy you use, the products you buy, should be such that you meet your current needs without compromising the ability of future of generations to meet their needs.

Payback ratios and Costs
Using payback ratios and costs is an economic approach to comparing energy sources. Payback ratio is defined as the energy output divided by the energy invested, or the “energy generated over the lifetime of the [energy generation] plant [compared] to the energy required to construct and maintain it” (Boyle et al.. 2003). A payback ratio of 1.0 indicates that the power source uses almost as much energy as it produces. Payback ratios consider such actions as building and maintaining the facility and the extraction, transportation, and processing of the energy. The following are typical values for energy options in the northeastern part of North America. For example, “over its working lifetime, a wind turbine is able to generate some 80 times the energy required to produce it” (Boyle 2004) as is shown in the table below.

Notice that biomass is listed twice. The payback ratio for biomass is 5 if the crops are grown specifically for energy production. If wastes from forestry, crops, manure, or municipalities are used, then the payback ratio is 27 (Godfrey et.al. 2003). This is because of the energy required to plant, maintain, and harvest energy production crops. Notice the high to low payback ratio order in which the renewables occur: hydroelectric, wind, solar, biomass, and fuel cell. It is important to understand that payback ratios are NOT necessarily reflective of sustainability. For example, hydroelectric dams have a high payback ratio but, after our field trip we know that there are strong negative environmental impacts associated with dams. Fuel cells have a low payback ratio because the technology is still quite expensive, as is solar, but we know that hydrogen has a very high sustainability potential.

Another way to examine energy sources is to compare their costs, most often labeled in cents per kilowatt hour (cents/kWh). The most recent edition of the California Energy Commission's Energy Technology Status Report (1996) lists the following costs for various fuels:

How YOU Can Become More Sustainable.
According to the Union of Concerned Scientists (2004) “electricity generation is the largest industrial polluter in the country.” Fossil fuels and nuclear power are the dirtiest energy sources and yet generate 90% of the electricity for the United States, producing 2/3 of the annual U.S. emissions of sulfur oxide, 30% of the nitrogen oxide emissions, and 40% of the carbon dioxide emissions. Toxic metal emissions and nuclear waste are also results of electricity generation. Right now, it is not possible to avoid fossil fuels and nuclear power altogether, but you, as an energy consumer, can help minimize their use by participating in green pricing, green marketing, or by purchasing green tags.

Green Pricing This is a service that may be provided by your local utility company. The customer does not switch energy providers, but chooses to pay a premium on their electricity bill. This money is used to help cover costs of purchasing clean energy (that is, produced from a renewable energy source). Consult the United States Department of Energy's Green Power Network at to find out if your local energy provider participates.

Green Marketing The customer actually switches to a chosen electricity provider. The customer can choose from a variety of suppliers and service offerings. This service is currently available in Illinois, Maine, Maryland, New Jersey, New York, Pennsylvania, Texas, Virginia, and the District of Columbia. Consult the Green Power Network at for a list of clean energy suppliers.

Green Tags Tradable Renewable Certificates (TRCs) , sometimes called green tags , are available for purchase from someone other than your electricity provider. The TRCs are measured in terms of credits, where one credit equals one kilowatt hour of electricity. Any quantity can be purchased and the money goes to support new renewable energy projects. Thus the consumer is paying for the benefit of adding clean, renewable electricity to the regional or national grid. This market strategy is ideal for people who live in states where green pricing and green marketing options are not available. A list of TRC marketers is available at the Green Power Network.

When considering any of these programs you may want to consider those that are Green-e certified. Green-e is a voluntary certification program for renewable electricity products. It establishes consumer protection and sets environmental standards. At www.green-e.org you can choose your state and view a list of those products and suppliers that are Green-e certified.

Additional ways that you can contribute to a more sustainable future:

• reducing levels of consumption
• purchase and use energy efficient appliances
• install compact flourescent lightbulbs anywhere possible
• live close to work or car pool
• consider alternative transportation such as bicycling, walking, bus riding
• buy and energy efficient vehicle
• install water efficient showerheads and toilets
• composte yard and kitchen food waste
• plant native vegetation in your landscaping
• purchasing products that can be recycled when they are no longer useable (look for the recycle logo on the product),
• purchasing products that are in containers that are recyclable (look for the recycle logo on the product),
• purchasing products that are made from post consumer products. Post consumer products are those that have been used before and recycled. Most products that are made from post consumer materials have a written statement, somewhere on the product or packaging, telling the consumer what percentage of the material is post consumer.
• limit family size to one or two children
• think about the impact your behavior will have on future generations and on the environment today

Every person can help move our society from a carbon-based (fossil fuel) economy to a bio-based economy. Bio-based products are those made from renewable plant or animal materials. These products are recyclable and biodegradable. As stated in our Biofuels field trip, The United States government is participating in purchasing bio-based products. Section 9002 of the 2002 United States Farm Bill mandates that government agencies purchase “bio-based materials in place of petro-based materials and products so long as they are competitive in cost, availability and performance” (Biobased Manufacturers Association 2004). Many bio-based products such as absorbents, adhesives, cleaning agents, fertilizers, packaging, paper products, solvents, and solutions for water and waste treatment are available to consumers. The Biobased Manufacturers Association and other similar organizations can be contacted to help market a bio-based product and/or to help purchasers from any company size or affiliation to locate and make decisions about purchasing bio-based products. A bio-based economy operates with more sustainability than a carbon-based economy. Think before you purchase. Will the product you are considering end up in a landfill after it is no longer useful or can it be recycled, reused, or refilled? The choices you make when buying any product sends a message to producers. It tells them what consumers want.  

Decarbonizing the modern world is going to require a change in paradigm, a change in the way people think and view the world. The World Alliance for Decentralized Energy (WADE) says that:

We must change the entrenched mindsets of governments and energy companies around the world. Their view is that the optimum solution for energy delivery is through conventional central electricity generation, connected to remote consumers by high-cost transmission and distribution networks, and separate heating and cooling. We have surely reached the time when we can say with confidence that this view is wrong.

(James and James 2002)

It is unlikely that any single renewable energy source will totally replace the energy obtained from fossil fuels any time soon. However, it IS likely that using all possible renewable energy sources simultaneously can reduce the demand for fossil fuels to such a point that fossil fuel availability could be considerably extended while at the same time producing a cleaner atmosphere and a cleaner, more sustainable world.

Becoming an informed consumer and a more sustainably oriented person begins with YOU. There are thousands of sources for information on sustainability and renewable energy sources, many of which have been mentioned in our Renewable Energy Virtual Field Trips. Read, learn, become informed, and make sustainable choices.

Recall our earlier questions:

•  What is a payback ratio?
•  What programs are available for consumers wanting to purchase green energy?
•  What are some things YOU can do to contribute to a sustainable future?

If you can't answer these, review the field trip again.

World Wide Web

Biobased Manufacturers www.biobased.org    (Sister organization to New Uses Council. Can take a developed product and help market it to global consumers. Mission is to promote excellence in the manufacture, sale, and use of biobased products and the responsible development of renewable resources.)

U.S. Department of Energy - Energy Information Administration. www.eia.doe.gov/fuelrenewable.html

U.S. Department of Energy. Energy Efficiency and Renewable Energy. Green Power Network www.eere.energy.gov/greenpower/

Union of Concerned Scientists www.ucsusa.org/clean_energy/renewable_energy/

Power Scorecard www.powerscorecard.org/

Biobased Manufacturers Association. 2004. The Biobased Revolution is Underway... Participate In It!. Pamphlet distributed by Biobased Manufacturers Association 11701 Borman Drive, Suite 300 St. Louis, MO 63146-4193. Pamphlet received in April 2004.

Boyle, Godfrey. 2004. Renewable Energy Power for a Sustainable Future . Second edition. Oxford University Press Inc., New York.

Boyle, Godfrey, Everett, Bob, and Ramage, Janet. 2003. Energy Systems and Sustainability Power for a Sustainable Future . Oxford University Press Inc., New York.

James and James. 2002. Cogeneration and On-Site Power Production. On-Line Magazine. Vol 3. NO. 3 May -June 2002.

L.T. Goodlife Publishing Company, Inc. P.O. Box 1943 Ossining, NY 10562. Retrieved April 2004.

Union of Concerned Scientists www.ucsusa.org/clean_energy/renewable_energy/

Special thanks to Dr. Daniel D. Chiras, author of Environmental Science:
Creating a Sustainable Future and Visiting Professor at Colorado College
for reviewing the content of this entire website.

Creation of the Renewable Energy Field Trips Web site was funded by
the Schreyer Institute for Teaching Excellence
and Penn State Erie, The Behrend College.