By Frank A. Wolak Market Design in an Intermittent Renewable Future ©SHUTTERSTOCK.COM/IURII MOTOV Cost Recovery With ZeroMarginal-Cost Resources Digital Object Identifier 10.1109/MPE.2020.3033395 Date of current version: 6 January 2021 january/february 2021 T THE BASIC FEATURES OF AN EFFICIENT SHORT-TERM wholesale market design do not necessarily need to change to accommodate a significantly larger share of zero-marginal-cost, intermittent renewable energy from wind and solar resources. A large share of controllable zero-marginal-cost generation does not create any additional market design challenge relative to a market with a large share of controllable positive marginal cost generation. Regardless of the technology, generation unit owners must recover their fixed costs from sales of energy, ancillary services, and long-term resource adequacy products. A larger variance in the hourly amount of energy produced by intermittent resources is the primary market design challenge associated with a zero-marginal-cost renewable future. The past 10 years in California have demonstrated that, as the amount of wind and solar generation capacity increases, the variance in hourly energy produced by these resources does too. This increase in supply uncertainty also increases short-term price 1540-7977/21©2021IEEE ieee power & energy magazine 29http://www.SHUTTERSTOCK.COM/IURII