Definitions of Energy Security on the Web:

• A reliable supply of affordable energy.
  www.inyoyucca.org/glossary.htm

   

• Energy security, or security of supply, is a key component of energy policy in many countries. Since all economic activity requires the use of energy resources, the continuing availability of energy at a price that protects economic growth is a major concern of governments.
  en.wikipedia.org/wiki/Energy security