How can U.S. transmission grids and wholesale energy markets adapt to the gigawatts of energy storage coming online over the next decade? In the near future, the scale of the batteries serving U.S. power grids is set to explode, increasing from about 1.5 gigawatts today to tens or hundreds of gigawatts by 2030. These batteries will play a vital role in shifting intermittent wind and solar power from when it’s produced to when it’s needed and serving broader grid services needs on an increasingly decarbonizing grid. But as a resource that can both absorb and discharge energy at a moment’s notice, batteries are very different from both dispatchable generators and intermittent wind and solar farms. That requires new technical and economic systems for managing and valuing them — and the grid operators that run wholesale electricity markets serving about two-thirds of the country are struggling to make those changes to keep up with the pace of growth.