Wind-Powered generating facilities are commonly known as "wind farms." Wind farm development in Greece is now rapidly spreading across Europe. Wind power is now the world’s fastest growing energy source. After more than 20 years of development and growth, the modern wind power industry has finally come of age.
Equipment and facility reliability, measured as “availability,” is now typically higher than 98 percent, with planned maintenance generally accounting for the remaining two percent. Manufacturers of wind turbine generators now offer comprehensive warranty programs, and kilowatt-hour production is normally insured against equipment failure. Although other forms of renewable energy exist and have application niches, wind energy is clearly the most cost-effective power source enabling utility-scale generation at costs competitive with fossil fuels. In fact, once environmental and health benefits are added, wind energy becomes the most competitive and sustainable energy technology available today.
Solar power can be used in both large-scale applications and in smaller systems for the home. Businesses and industry can diversify their energy sources, improve efficiency, and save money by choosing solar technologies for heating and cooling, industrial processes, electricity, and water heating. Homeowners can also use solar technologies for heating and cooling and water heating, and may even be able to produce enough electricity to operate "off-grid" or to sell the extra electricity to the utilities, depending on local programs. The use of passive solar heating and daylighting design strategies can help both homes and commercial buildings operate more efficiently and make them more pleasant and comfortable places in which to live and work.
Beyond these localized uses of solar power, utilities and power plants are also taking advantage of the sun's abundant energy resource and offering the benefits to their customers. Concentrating solar power systems allow power plants to produce electricity from the sun on a larger scale, which in turn allows consumers to take advantage of solar power without making the investment in personal solar technology systems.
Biomass is a renewable energy source because the energy it contains comes from the sun. Through the process of photosynthesis, chlorophyll in plants captures the sun's energy by converting carbon dioxide from the air and water from the ground into carbohydrates, complex compounds composed of carbon, hydrogen, and oxygen. When these carbohydrates are burned, they turn back into carbon dioxide and water and release the sun's energy they contain. In this way, biomass functions as a sort of natural battery for storing solar energy. As long as biomass is produced sustainably—with only as much used as is grown—the battery will last indefinitely.