Sustainable development is increasingly becoming a goal to which numerous countries throughout the world aspire. Overall sustainability has been defined in many ways, and is often considered to have three distinct components: environmental sustainability, economic sustainability and social sustainability. These three factors when considered separately usually pull society in different directions (e.g., economic sustainability may be achieved at the expense of environmental and social sustainability). Overall sustainable development in general requires the simultaneous achievement of environmental, economic and social sustainability. Achieving this balance is indeed a challenging task.
Although energy is not directly one of the three components of sustainability cited above, it is indirectly linked to each. That is, energy resources drive much if not most of the world's economic activity, in virtually all economic sectors, e.g., industry, transportation, residential, commercial, etc. Also, energy resources, whether fossil fuels or renewables, are obtained from the environment, and wastes from energy processes (production, transport, storage, utilization) are typically released to the environment. Finally, the services provided by energy allow for good living standards, and often support social stability as well as cultural and social development. Given the intimate ties between energy and the key components of sustainable development, it is evident that the attainment of energy sustainability is a critical aspect of achieving sustainable development, in individual countries and globally.
The fact that all countries utilize energy resources, and that the impacts on the environment of energy processes are both local and global, and given that the world's economy Is becoming increasingly globalized, it has become increasingly apparent that the quest for energy sustainability is indeed global in extent.
Energy sustainability is taken here not just to be concerned with sustainable energy sources, but rather to be much more comprehensive. That is, energy sustainability is taken to involve the sustainable use of energy in overall energy systems. Such systems include processes and technologies for the harvesting of energy sources, their conversion to useful energy forms, energy transport and storage, and the utilization of energy to provide energy services such as operating a computer, lighting an office or keeping a person warm in winter. Thus, energy sustainability goes beyond the search for sustainable energy sources, and implies sustainable energy systems, i.e., systems that use sustainable energy resources, and that process, store, transport and utilize those resources sustainably.
The objective of this article is to identify and examine the key factors that need to be addressed to achieve energy sustainability in a global context. An engineering perspective is taken to be pragmatic, and an illustration is presented to provide an example of a practical future sustainable energy option.
The focus of this article is on technical aspects of the quest for energy sustainability. In many ways, it is evident that the author takes an engineering approach, which is likely influenced by his being or having been a professional engineer, an engineering educator and administrator and the head of engineering societies. This approach is taken to be pragmatic, which is often at the centre of engineering activities. Also, this approach focuses on the technical necessities to achieve energy sustainability, and less on the roles of economics, politics and other non-technical factors. Consequently, the present article is not the approach that would likely be taken by economists, business and industry leaders, politicians or sociologists, who have different foci and different paradigms through which they view energy sustainability. Although these other perspectives can be useful and informative, the approach taken here is intentional and is considered by the author to be critical for addressing the fundamental issues and challenges relating to energy sustainability. …