Since James Watt, a Scottish inventor, improved the efficiency of steam engine, human civilization relies more and more on a steady supply of energy. Today we are at a transitional age. On one hand, we see technology advances in the exploration and development of oil and gas, a depleting resource; we see growth in handling aging and decommissioning. On the other hand, we see ideas and plans for the future's new energy structure. This symposium is about energy challenges, the underlying energetic basis (mechanics) for society, involving multiple disciplines in technology, science, management and policy-making. The topics include both fossil fuels and many different forms of renewable energy. In addition, we will discuss issues related to energy policy and economy, energy efficiency, safety and environment. The purpose is to gain a big picture about energy challenges and solutions.