能源有效性与可再生能源(精)

Energy: Forms
Kinetic energy Potential energy Heat
Glossary
kinetic energy
Energy that matter has because of its mass and speed or velocity. Compare potential energy.
Chapter 8
Energy Efficiency and Renewable Energy 能源有效性与可再生能源
Key Concepts
Energy Evaluating energy resources Improving energy efficiency Types and uses of solar energy
High-quality energy Low-quality energy
Evaluating Energy Resources
Renewable energy Non-renewable energy
Future availability
Net energy yield Cost Environmental effects
Types and uses of flowing water Uses of wind energy Types and uses of biomass Use of hydrogen as a fuel Use of geothermal energy Decentralized power systems
As the water boils, heat from the hot stove burner and pan radiate into the surrounding air, even though air conducts very little heat.
Energy: Quality
Glossary
nonrenewable resource Resource that exists in a fixed amount (stock) in various places in the earth's crust and has the potential for renewal by geological, physical, and chemical processes taking place over hundreds of millions to billions of years. Examples are copper, aluminum, coal, and oil. We classify these resources as exhaustible because we are extracting and using them at a much faster rate than they were formed. Compare renin the bottom of a pan causes some of the water to vaporize into bubbles. Because they are lighter than the surrounding water, they rise. Water then sinks from the top to replace the rising bubbles.This up and down movement (convection) eventually heats all of the water.
Glossary
energy efficiency Percentage of the total energy input that does useful work and is not converted into low-quality, usually useless heat in an energy conversion system or process. See energy quality, net energy. Compare material efficiency. geothermal energy Heat transferred from the earth's underground concentrations of (1) dry steam (steam with no water droplets), (2) wet steam (a mixture of steam and water droplets), or (3) hot water trapped in fractured or porous rock.
potential energy
Energy stored in an object because of its position or the position of its parts. Compare kinetic energy
Transfer of Heat Energy
Convection Conduction Radiation
Heat from a stove burner causes atoms or molecules in the pan’s bottom to vibrate faster. The vibrating atoms or molecules then collide with nearby atoms or molecules, causing them to vibrate faster. Eventually, molecules or atoms in the pan’s handle are vibrating so fast it becomes too hot to touch.