Geothermal Resource Descriptions

Part 4 of Geothermal Energy Under Our Feet. Hydrothermal A hydrothermal system is defined as a subterranean geothermal reservoir that transfers heat energy upward by vertical circulation of fluids driven by differences in fluid density that correspond to differences in temperature (see Figure 2). Hydrothermal systems can be classified into two types—vapor-dominated and hot water— […]

United States Climate Change Impact Summary

Part 2 of United States Climate Change Impact. Observations show that warming of the climate is unequivocal. The global warming observed over the past 50 years is due primarily to human-induced emissions of heat-trapping gases. These emissions come mainly from the burning of fossil fuels (coal, oil, and gas), with important contributions from the clearing […]

Today’s Alternative Fuel Choices: Propane

Part 7 of Advanced Technology and Alternative Fuel Vehicles. Liquefied petroleum gas (LPG), commonly called propane, is a mixture of at least 90 percent propane, 2.5 percent butane and higher hydrocarbons, and ethane and propylene make up the remaining balance. It is a byproduct of natural gas processing and/or petroleum refining. A propane-powered vehicle can’t […]