The large magnitude of solar energy available makes it a highly appealing source of electricity. The United Nations Development Programme in its 2000 World Energy Assessment found that the annual potential of solar energy was 1,575â49,837 exajoules (EJ).
Definition of IRONWOOD. 1. : any of numerous trees and shrubs (as a hornbeam or hop hornbeam) with exceptionally tough or hard wood. 2.: the wood of an ironwood.See ironwood defined for kids.ADVERTISEMENT.. : any of numerous trees and shrubs (as a hornbeam or hop hornbeam) with exceptionally tough or hard wood. 2. : the wood of an ironwood. See ironwood defined for kids.
Lesson Summary. Iron is an abundant metallic element, formed by stellar fusion. It is mined primarily from rocks containing hematite and magnetite. Although once used in its pure form to make a variety of items (thus, the Iron Age and Iron Horse), today its principal use is as the primary component of steel.