FERC last week cited the filed rate doctrine on retroactive ratemaking to reject a pair of SPP requests for waivers to resettle billing errors.

The commission on Thursday denied a waiver of the 365-day limitation period to modify settlements in SPP’s market-to-market (M2M) process with MISO (ER19-477) and a one-year billing adjustment limitation to resettle past invoices because of a billing error (ER18-2404).

FERC found the waiver requests to be retroactive ratemaking, saying the doctrine “forbids a regulated entity to charge rates for its services other than those properly filed with the appropriate federal regulatory authority.” The rule also “prohibits the commission from adjusting current rates to make up for a utility’s over- or under-collection in prior periods,” it said.

The commission said the first request did not give ratepayers sufficient notice that old M2M settlements were subject to change.

The settlements in question date back to 2015 and 2016. SPP said that between when the M2M process began and before the RTOs signed a memorandum of understanding, they discovered four instances between March 2015 and December 2016 where issues with flowgate use, classification or reporting during M2M events resulted in incorrect settlement calculations.

SPP said it did not reach final agreement on the M2M resettlement process and the four settlements until October 2018. The resettlements amount to a $1.75 million payment from SPP to MISO. SPP has accumulated more than $168 million in settlements from MISO since the process began. (See SPP M2M Hits Staggering $168.1M.)

The RTO also tried to correct a billing error of $901,758 for point-to-point transmission service to Nebraska Public Power District. SPP said a non-billable transaction was changed to billable in its settlement, resulting in NPDD being double billed from June 2016 to December 2017. The 2016 charges were not resettled when staff set out to correct the error in January 2018.

SPP, MMU Given Time to Verify Costs

FERC on Wednesday did approve a request by SPP and its Market Monitoring Unit to waive three tariff provisions that will allow more time to verify costs and settle disputes over market transactions during the February winter storms (ER21-1331).

FERC’s approval adds 40 days to the normal 35-day deadline for market participants to submit information for offers above $1,000/MWh to be recovered through make-whole payments. It also allows 105 days instead of 45 to review cost submissions and waives the limitation on a market participant’s ability to dispute consecutive settlement statements.

Numerous market offers exceeded SPP’s $1,000/MWh cap during the winter event, peaking at $4,274/MWh. The MMU is reviewing the offers under FERC Orders 831 and 831-A, which require that energy suppliers receive a reasonable opportunity to recover their actual costs of providing energy.