Understanding the maximum storage requirements for the grid

When the discussion turns to storage on the grid for renewable energy, the maximum amount required is always estimated. In this work, the team looked at a number of scenarios for storage requirements ranging from low levels of renewables to a mixture of renewables to pure renewable scenarios. From this one seemingly absurd scenario was chosen because it puts an upper bound on the amount of long term storage required for a renewable powered electric grid. The paper looks at 4 large Independent System Operators (ISO/RTO) with significant wind penetration and projects the maximum storage based on a wind only scenario. The 4 ISO serve more than half of the people in the United States and Canada.