http://www.eia.doe.gov/kids/energy.cfm?page=about_forms_of_energy-basics#top-container
http://www.kids.esdb.bg/index.html
http://energyquest.ca.gov/index.html
While I was researching, the most impactful websites helped students see that science was relevant in their lives. The government website gives a great overview of the types of energy that is used and how we can help our environment.
These tools would help my students become more scientifically literate students by fostering and support their understanding of energy sources. Part of being scientifically literate is learning how to use the information on the computer. Researching is a skill that they will use for the rest of their education careers.
It would be interesting to have students use these websites and create a brochure on a new way of energy and why it is the best for our ecosystem. Students could work in groups and develop a model based off the ones that they find from the websites. The website from California has an interactive room that students can find timelines of energy usage and scientists that were involved in the creation or improvement of different energies sources.
Some challenges of these sources would be the complexity of the material. My third graders are limited because they do not have experience using the internet as a research tool and there is not many different sources that are not simplified.