Abstract:  Increasing the share of energy produced by wind turbines, solar photovoltaics, and solar thermal power plants helps society address many key energy challenges including climate change, environmental degradation, and energy security. However, these renewable energy resources present new challenges, notably that their power production is intermittent – they produce when the wind is blowing and the sun is shining, not necessarily when we need it.  In this talk, I will describe how distributed flexible resources such as commercial buildings, residential electric loads, and distributed storage units can support high penetrations of intermittent renewables and provide other services that make the grid run more efficiently and make power less expensive.  As an example, I will show how one can use Markov models and linear/nonlinear filtering techniques to centrally control aggregations of loads to provide power system services with high accuracy, but low requirements for sensing and communications. I find that, depending on the performance required, loads may not need to provide state information to the central controller in real time or at all, which keeps installation and operation costs low.  Additionally, I will discuss a number of practical issues including estimates of the resource size and revenue potential.  Finally, I will describe several new research directions including modeling load aggregations as uncertain reserves for day-ahead power system planning and real-time security. Bio:  Johanna Mathieu is a postdoctoral researcher in the Power Systems Laboratory at ETH Zurich, Switzerland.  In May 2012 she received her PhD in mechanical engineering from the University of California at Berkeley. She has a BS from MIT in ocean engineering and an MS from UC Berkeley in mechanical engineering.