Exergy analysis enables one to evaluate quantitatively the causes resulting in increases of exergy due to thermodynamic imperfections of thermal and chemical processes. Exergy express the quality of energy and can be defined as the minimal work necessary to produce a material in its specified state from materials common in the environment in a reversible way, heat being exchanged only with the environment. On the other hand, achieving sustainable solutions to today's energy and environmental problems needs long-term planning and actions. Energy issues are particularly prevalent at present and renewables appear to provide one component of an effective sustainable solution. Discussed in this article are possible future energy-utilization patterns and related environmental impacts, potential solutions to current environmental problems, renewable energy technologies and their relations to sustainable development, and how the principles of thermodynamics via exergy can be beneficially used to evaluate energy systems and technologies as well as environmental impact. Throughout the article, current and future perspectives regarding thermodynamics and sustainable development are considered.