By Amanda Durish Cook

FERC on Thursday approved a new MISO Tariff provision that allows transmission owners to recover interconnection facility operations and maintenance costs from interconnection customers.

The decision allows MISO to include a new rate schedule — Schedule 50 — to allow TOs to recoup costs from interconnection customers for “reasonable expenses, including overheads, associated with operation and maintenance, and repair” of TO-owned interconnection facilities (ER20-170).

MISO TOs filed in October for the new rate schedule.

“While relevant provisions of a MISO generator interconnection agreement … already explicitly provide that interconnection customers ‘shall be responsible’ for all reasonable [operations and maintenance] expenses, there is presently no mechanism in the Tariff to enable the calculation and recovery of such expenses from interconnection customers,” the TOs explained to FERC.

MISO joined the filing as administrator of its Tariff but took no stance on the proposed revisions.

The TOs plan to allocate O&M annual charges based on a calculation involving the interconnection facilities’ installed costs as a share of a total annual transmission gross plant. When installed costs aren’t available for calculation, TOs will have to submit filings so FERC can review the alternate calculations.

In accepting the new schedule, FERC disagreed with renewable energy proponents that the Schedule 50 approach would “unduly” shift costs to interconnection customers. Some had argued that a process including transmission facilities didn’t translate well for interconnection facilities because they’re newer and less prone to maintenance charges. But the commission said the average useful life or O&M costs of an interconnection facility aren’t much different than the average useful life or O&M costs “of other similar transmission facilities.”

Other clean energy advocates said O&M costs should be assigned directly to interconnection customers instead of using a calculation. FERC again disagreed.

” … [E]ven in the instances where transmission owners utilize direct billing, not all costs are able to be directly assigned, some are assigned based on various allocators, and some costs are not even recovered,” the commission explained.