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.
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.
The figure summarizes some of the key variations amongst the six illustrative scenarios used by the Intergovernmental Panel on Climate Change (IPCC) in considering possible future emissions of greenhouse gases during the 21st century.
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 resource consists of an interactive table with a comprehensive list of 29 Greenhouse Gases, their molecular structures, a chart showing a time series of their atmospheric concentrations (at several sampling sites), their global warming potential (GWP) and their atmospheric lifetimes. References are given to the data sets that range from the mid-1990s to 2008.