This course examines the production and consumption of energy from a systems perspective to accelerate sustainable energy transitions and climate solutions. Sustainability is examined by studying global and regional environmental impacts, economics, energy efficiency, consumption patterns and energy policy. The physics of energy and energy accounting methods are introduced at a basic level. The current energy system that encompasses supply (resource extraction, conversion processes) and demand (or end uses in buildings, transportation, industrial sectors) are then characterized to understand challenges and opportunities for energy system improvement. Strategies and interventions to address climate change and other sustainability challenges are explored in depth with an emphasis on renewable energy technologies (e.g., wind, photovoltaics, geothermal, and biomass), building technologies, alternative vehicle technologies, and end-use efficiency and conservation.