This suite of short video clips is part of a series produced by the Switch Energy project. There are several video segments that discuss different perspectives of biofuels as a renewable source of energy.

This animation illustrates how heat energy from deep in Earth can be utilized to generate electricity at a large scale.

This set of flow charts illustrates energy sources and uses in 136 countries around the world. The data from 2007, but is still useful for comparing energy patterns in different countries. This is the first comprehensive package of worldwide, country-level energy flowcharts that has been produced.

This introductory video describes the basic principles of residential geothermal heat pumps.

Sankey (or Spaghetti) diagrams parse out the energy flow by state, based on 2008 data from the Dept. of Energy. These diagrams can help bring a local perspective to energy consumption. The estimates include rejected or lost energy but don't necessarily include losses at the ultimate user end that are due to lack of insulation.

This interactive diagram from the National Academy of Sciences shows how we rely on a variety of primary energy sources (solar, nuclear, hydro, wind, geothermal, natural gas, coal, biomass, oil) to supply energy to four end-use sectors (residential, commercial, industrial, and transportation). It also focuses on lost or degraded energy.

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.