MISO this week filed to intervene in Indianapolis Power & Light’s appeals challenging FERC decisions on energy storage compensation and dispatch within the RTO.

In a June 11 filing, MISO said it had “direct, substantial and legally protectable interest that would be subject to impairment” by IPL’s litigation. The RTO also said its independence from its members ensures “no other party can adequately represent” its interest in the case that could force changes to its Tariff (18-2104).

The case is pending before the 7th U.S. Circuit Court of Appeals after IPL filed a petition for review in mid-May, challenging FERC orders stemming from the company’s 2016 complaint that MISO’s Tariff unreasonably limited energy storage participation. (See MISO Ordered to Change Storage Rules Following IPL Complaint.) While the commission last year directed MISO to draft rules to open its markets to storage, it did not order compensation for automatic frequency control or find that the RTO’s current dispatch rules could harm storage battery life, even after IPL sought rehearing on the two issues. (See “No Rehearing for IPL,” FERC OKs MISO Plan to Expand Storage.)

In its petition for review, IPL pointed out that FERC’s original order on its complaint in early 2017 was issued two days before the commission lost its quorum and was reduced to just two commissioners.

— Amanda Durish Cook