Going completely renewable -- what would it take?
Sustainability is a grand challenge of our age. Modern society provides many benefits, but it runs on energy. Some progress has been made in de-coupling standard of living from energy use, but that is just a small part of the solution. As a society, we are just beginning to understand the substantial external costs of the old ways of producing energy, and we have created a very large environmental debt that must be repaid. Ultimately, all our energy comes either from the sun (solar, wind, hydro, food, fossil fuels), from geological processes (geothermal, tidal), or from fissile materials. Much of the focus on sustainability is on the energy sector, especially the electric grid. This is partly because so much of our electric power is made by burning coal at 33%-40% efficiency, but more importantly because many non-electric uses of energy, like transport, can be substituted with sustainable electricity, in many cases at much higher efficiency, and increasingly at lower cost. Indeed, the proportion of solar and wind has increased dramatically in many areas of the world in the last few years. However, without major changes in the way electrical power is distributed and managed, many areas are near the limit of what they can handle while maintaining grid reliability. We will focus on the problem of intermittency and various approaches to addressing it. We are especially interested in market-driven approaches that do not require centralized control regimes, or that place such regimes in a market context. The intermittency problem must be addressed at a range of time scales from years to milliseconds. We will examine a variety of proposed solutions, from investment in new transmission infrastructure to short-timescale management of demand-side resources, and discuss some approaches, along with advantages and limitations, of market-based solutions. Along the way we will also look at what some of the new information systems and communications infrastructure that will be needed to enable these solutions.