The grid operator sees few if any showstoppers in interconnecting storage to California\u2019s power transmission system, California Independent System Operator managers said Aug. 13. Studies under the grid operator\u2019s existing interconnection procedures are underway for 39 storage projects, said Tom Flynn, CAISO infrastructure policy development manager. Combined, the projects would have storage capacity of 2,320 MW, Flynn said during a workshop on storage interconnection this week. They include 27 stand-alone projects with 1,342 MW of capacity and 12 projects coupled with generation facilities that could store 979 MW of power. Of the stand-alone projects, almost all would use batteries to store power. Flynn called the interest in storage unprecedented and attributed it largely to the California Public Utilities Commission\u2019s target for the state\u2019s investor-owned utilities to procure 1,325 MW of storage capacity by 2020. The commission sees storage as necessary to integrate greater levels of intermittent solar and wind power into the state\u2019s grid. The average size of projects submitted for interconnection ranges between 50 and 80 MW, according to Arthur O\u2019Donnell, commission senior regulatory analyst. After the commission ordered utilities to procure storage, Flynn explained the grid operator envisioned having to amend its interconnection tariff. However, after examining its interconnection process and proposed storage facilities more closely, he said it\u2019s doubtful formal amendments to the tariff are needed. \u201cSo far we haven\u2019t identified any specific tariff changes we think are needed to connect storage to the CAISO-controlled grid,\u201d said Flynn. The grid operator believes it can successfully apply its existing interconnection process for both pending and future storage interconnection requests. Under the interconnection process, Flynn explained, the grid operator is treating storage facilities as if they were generation facilities, even though they will both draw and feed power into the grid. Flynn pointed out that\u2019s possible because the grid operator will control both charging and power injections by storage devices on the grid just as it does generation facilities. For instance, at times the grid operator may have to curtail charging to prevent congestion from developing on the transmission system, according to Songzhe Zhu, CAISO power system transmission planner. Also, just like new generation, she added, interconnecting storage may in some cases require network upgrades. While interconnection appears to fairly straightforward, Flynn acknowledged \u201cthere\u2019s a much broader array of storage issues that need to be addressed.\u201d Among them are decisions about the market structure and pricing for storage. To iron out these issues, the grid operator is joining with the utilities commission and California Energy Commission to develop an \u201cenergy storage roadmap.\u201d It will address what Flynn called \u201cchallenges and barriers for energy storage.\u201d The first workshop on the roadmap is slated for Sept. 4. A final roadmap is due by the end of the year.