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.

Current Issues and the Future

.
With the growing worldwide demand for electric power and the rising concern about global warming, many experts believe that the use of wind energy will continue to increase. As wind power becomes an increasingly cost-effective source of electricity, the market for wind power should continue to expand. Some environmental and political factors, however, will also influence the growth of wind energy.

Wind Energy and the Environment

Although wind energy is a relatively clean means of generating electricity, there are associated impacts. One of these is the potential of an array of turbines to alter the visual quality of the landscape, especially when located in a scenic area. In addition to aesthetic concerns, noise associated with spinning wind turbine rotors has generated complaints from the public. Another environmental concern associated with wind energy is the impact on wildlife. Wind turbines in some areas are responsible for killing birds—including some protected species—that are accidentally caught in the rotor blades.

Some of these environmental concerns are being addressed by more careful siting of wind turbines. Other concerns, such as the noise of spinning rotor blades, may be partially solved by design refinements that successfully reduce aerodynamic and mechanical noise.