This animated slideshow introduces biodiesel as a fuel alternative. With concern about the use of petroleum-based fuels at an all-time high, biodiesel is experiencing a popularity surge. And algaeâotherwise known to some as pond scumâ are grabbing headlines as the next potential biodiesel superstar. But how and why do algae make oil? And why do they make so much of it? In this audio slide show, U.C. Berkeley's Kris Niyogi describes the process and its potential.

This simplified animation of a geothermal power plant from the U.S. Department of Energy illustrates commonalities with traditional power-generating stations. While there are many types of geothermal power plants, this animation shows a generic plant.

This interactive visualization provides information in text, graphic, and video format about renewable energy technologies. Resource in the Student's Guide to Global Climate Change, part of EPA Climate Change Division.

This video segment examines ethanol, a cleaner-burning fuel alternative to gasoline, and the efforts to produce it more efficiently.

Students investigate passive solar building design with a focus on heating. Insulation, window placement, thermal mass, surface colors, and site orientation are addressed in the background materials and design preparation. Students test their projects for thermal gains and losses during a simulated day and night then compare designs with other teams for suggestions for improvements.

This video addresses the importance of efficiency in providing power to an increasingly large global population.

In this lab activity, students investigate how to prepare a biofuel source for conversion to a combustible product. The activity models how raw materials are refined to process liquid fuels.

In this learning activity, students use a web-based carbon calculator to determine their carbon footprint on the basis of their personal and household habits and choices. Students identify which personal activities and household choices produce the most CO2 emissions, compare their carbon footprint to the U.S. and global averages, and identify lifestyle changes they can make to reduce their footprint.

This short video reviews how nations and individuals can work together to reduce the emission of CO2. It discusses strategies to reduce greenhouse gas emissions (energy conservation, renewable energies, change in energy use) and the role that government can play in this process.

This video describes how geothermal heat resources in California have been tapped to supply 850 MW of electricity. Images and animations show how the area known as The Geysers has been developed to capture steam, produced from trapped rainwater and heated by the earth. Major challenges include finding suitable geothermal resources to develop, and ensuring that underground water is replenished.