Energy security is the assurance that the energy needs of a nation or region are met in a reliable and sustainable manner. It is achieved through the availability of energy resources, the diversity of those resources, and the ability of those resources to be accessed in a timely manner. To ensure energy security, nations must have a reliable and secure supply of energy and the means to access it in a cost-effective manner. Additionally, energy security must also be considered in terms of environmental protection and the potential for future resource scarcity.