The current age is one in dire need of teaching engineers of all branches about sustainability. The principle is that engineering choices have to be decided in the framework of constraints related to energy and materials and decreasing wastes. The federal government would be the most appropriate entity to take actions to drive the burgeoning of sustainable energy technologies. Coal is the most popular fuel globally used with the Rankine cycle for electric power generation. Most of the electric power produced in the world is generated via the Rankine cycle. One of the most efficient simple thermodynamic cycles for electric power generation currently is the gas cycle using natural gas, with the additional potential to decouple the energy sector from the water sector. The combined gas and Rankine cycle is an even more efficient cycle to generate electric power, but then couples the energy sector again to the water sector. Carbon dioxide, the greenhouse gas with the longest half-life, is still produced with the gas turbine cycle, but to a lesser degree than the Rankine cycle using coal. The main components of the sustainability aspects of the energy sector are outlined. A number of themes related to sustainability in the energy sector are also presented.