MISO and its transmission owners last Wednesday requested an additional nine months to refund transmission customers after FERC changed the TOs’ return on equity last year.

MISO and the TOs said they need until June 30, 2022, to crunch refund amounts. They said the existing Sept. 23 refund deadline was unattainable (EL14-12-004).

FERC last year enacted a 10.02% ROE for transmission rates effective Sept. 28, 2016, superseding the 9.88% and 10.32% ROEs approved in 2019 and 2016, respectively. Those figures were intended at different times to replace the 12.38% ROE established in 2002, which FERC deemed excessive years ago.

The ROE saga roiled for years while FERC tried to align a prescribed “zone of reasonableness” that better reflected the financial data investors use when deciding to back transmission projects.

FERC ultimately said the 10.02% ROE should be considered effective Sept. 28, 2016. In all, MISO TOs must refund customers for the November 2013-February 2015 and Sept. 28, 2016-Dec. 23, 2020 periods. (See FERC Ups MISO TO ROE, Reverses Stance on Models.)

MISO said it was requesting the extension with the “experience of many additional months of work on the resettlement process” under its belt.

“The majority of the refunds are expected to be complete before the end of 2021. MISO and its transmission owners have completed refunds for years 2013 through 2016 and currently are focused on refunds for the years 2017 and 2018, which are the years that involve the majority of the refund dollars,” the RTO explained to the commission.

The grid operator said it has completed all resettlements for TOs who use a historical test year methodology to calculate their transmission rates.

However, MISO said the remaining one-third of transmission owners use more complex forward-looking transmission rates with a true-up mechanism. It said the refund process is two-fold for TOs with forward-looking transmission rates because ROE revisions must be made through both the forward rate and the true-up.

The RTO also said it had already worked through some refunds under the 9.88% ROE before FERC declared the 10.02% figure effective last May. MISO said it then had to resettle and shave some refunds.