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.

In this activity, students explore the basic living requirements of algae (phytoplankton)through hands-on experience and an interactive game. Students investigate what algal biofuels are, how they are made, where they can grow, and, most importantly, why this topic should be investigated. Algal biofuels are an emerging source of renewable energy.

This is a team-based activity that teaches students about the scale of the greenhouse gas problem and the technologies that already exist which can dramatically reduce carbon emissions. Students select carbon-cutting strategies to construct a carbon mitigation profile, filling in the wedges of a climate stabilization triangle.

In this activity, students explore real data about renewable energy potential in their state using a mapping tool developed by NREL (National Renewable Energy Laboratory) to investigate the best locations for wind energy, solar energy, hydropower, geothermal energy, and biomass.

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.

This hands-on activity introduces students to the process of fermenting different carbohydrate sources into ethanol. Teachers demonstrate yeasts' inability to metabolize certain food sources.

In this activity, students consider the impact and sustainability of use of different classes of biofuels on the economy, the environment, and society. Students also learn about bioelectricity and how converting biomass to electricity may be the more efficient way to fuel cars in the 21st century.

In this video, students explore the work of Jay Keasling, a biologist who is experimenting with ways to produce a cleaner-burning fuel from biological matter using genetically modified microorganisms.

This video is one of a series of videos from the Switch Energy project. It describes three types of geothermal sources -- rare ones in which high temperatures are naturally concentrated near the surface, deep wells that require fracturing the rock and then circulating water to bring heat to the surface, and low temperature sources that use constant temperatures just below the surface to heat or cool a building. The latter two are more widely available but cost-prohibitive today.

In this activity, students conduct a life cycle assessment of energy used and produced in ethanol production, and a life cycle assessment of carbon dioxide used and produced in ethanol production.