On June 28, NEPGA and EPSA jointly filed a Request for Rehearing of FERC’s Order accepting ISO-NE’s proposed Net Cost of New Entry (CONE) value for effect beginning FCA 16, and its Order denying NEPGA’s related complaint (Docket No. ER21-787 and EL21-26). FERC conditioned its acceptance on ISO-NE adding the cost of on-site gas compression to the Reference Unit costs (as NEPGA argued). FERC rejected several NEPGA arguments, which NEPGA and EPSA now raise on rehearing, including: (1) FERC violated the filed rate doctrine by accepting a Tariff change to the definition of Net CONE for effect on May 29, a date well after ISO-NE’s application of the revised definition in the NEPOOL process and ISO-NE’s filing of the rate with FERC; (2) FERC’s order was arbitrary and capricious and not supported by substantial evidence because it failed to respond to serious objections raised by NEPGA and others, ignored substantial evidence contrary to its conclusions while accepting proposals based on little more than ISO-NE’s say-so, departed from Commission precedent without adequate explanation, and otherwise failed to satisfy the requirements of reasoned decision-making. FERC must take action on the Request for Rehearing within 30 days (i.e., by July 28) or it will be deemed denied (though FERC may issue an order on rehearing after the 30 days so long as it issues the order before the Circuit Courts take jurisdiction (should any party appeal)).