1. Energy Resources

2. What are energy resources?
An energy resource is anything that can be used to generate power for human use. There are two categories of energy resource:
non-renewable energy resources will eventually run out – once used they cannot be used again. Examples are fossil fuels (coal, oil, natural gas) and nuclear fuels (uranium, plutonium).
Photo credit: © 2012 Warren Gretz / NOE / NREL
Cherokee Station coal-powered plant, Denver, Colorado
renewable energy resources can be replaced or regenerated and will never run out. Examples are wind, hydroelectricity and solar power.

3. What is biomass? Photo credits
biomass combustion: © 2012 Virginija Valatkiene, Shutterstock.com
biofuels: © 2012 Nebraska Soybean Board / NREL
A soybean powered bus that runs on soybean bio-diesel.
biogas: © 2012 California Polytechnic State University / NREL
Anaerobic digester and biogas storage on a pig farm in The Philippines. 3

4. How do wind turbines work?
Wind turbines have large blades that capture the kinetic energy of the wind.
This kinetic energy directly turns a turbine and generates electricity.
Wind turbines are a source of 'clean energy’ as they do not produce polluting waste.
However, some people consider them to be noisy and an eyesore. There is also some concern that, if wind turbines are poorly located, they could kill migrating birds. 4

5. How does a hydroelectric dam work?
Photo credit: © 2012 NREL / US Army Corps of Engineers
The Ice Harbor Dam across the Snake River in the US state of Washington. It has a capacity of 600–700 MW.
Teacher notes
This four-stage animation illustrates how hydroelectric power works. While viewing the animation students could be asked to consider the energy transfers that are taking place and the possible environmental impacts of hydroelectric power. 5

6. How is tidal power used? Teacher notes
This four-stage animation can be used to demonstrate how tidal power works. When showing the animation, it is important to stress that electricity is only generated when the tide is flowing in or out but not when the tide is at its highest or lowest points. 6