Utility Dive summarizes comments filed about grid operators' plans to implement FERC's energy storage rule (Order 841). The article references comments from AEE on PJM Interconnection's plans. See excerpts below and the entire Utility Dive story here:
As energy storage becomes more economically competitive with more traditional forms of merchant generation, access to wholesale power markets is seen as an important addition to the technology's opportunities on the contracted side. However, questions remain about the effective implementation of the federal order that seeks to create consistent opportunities for storage to compete in wholesale energy markets.