Matter & Energy


Matter is composed of atoms or groups of atoms called molecules. The arrangement of particles in a material depends on the physical state of the substance. In a solid, particles form a compact structure that resists flow. Particles in a liquid have more energy than those in a solid. They can flow past one another, but they remain close. Particles in a gas have the most energy. They move rapidly and are separated from one another by relatively large distances.

The Modern Wind Energy Industry

.
Many countries began exploring alternative sources of energy during the oil shortages of the 1970s. As improvements in wind energy technology have evolved, the modern wind energy industry has emerged. Increasingly, modern wind turbines produce electric power as efficiently as other power generation technologies. One of the major obstacles for developing wind energy is finding suitable terrain and wind conditions.

Placement of Wind Turbines

Wind Turbines
Wind speeds in the Lake Benton, Minnesota, area average about 26 km/h (16 mph), making it the windiest region in the state. These turbines are equipped with special features to operate in this cold climate.

Location is critical for maximizing the electricity wind turbines can produce. The amount of kinetic energy available in the wind is a cubic function of wind speed—that is, for every doubling of wind speed, there is a corresponding eight-fold increase in available energy. This exponential relationship between wind speed and wind energy makes location extremely important. A site with high average wind speeds can provide considerably more wind energy than a site with only slightly lower wind speeds.

For most continental locations, winds are strongest during winter and spring and weakest during summer and fall. Regional weather patterns and local topographic conditions can also cause wind patterns to vary.

See Wind Power Plants; Reliability of Wind Energy