By Amanda Durish Cook

CARMEL, Ind. — MISO and its stakeholders have agreed on a plan to treat merchant HVDC lines as transmission instead of generation when physically connecting to the RTO’s system.

A year in the works, the proposed Tariff revision would subject merchant HVDC lines to MISO’s traditional transmission schedule charges and make them ineligible for interconnection service. The RTO will file the proposal with FERC by the end of this month.

Speaking at a March 14 Planning Advisory Committee meeting, MISO Director of Resource Utilization Vikram Godbole said the proposal does not prescribe any revenue plans for developers of merchant HVDC service. Developers would instead be responsible for determining the “net economic viability of their merchant HVDC project by considering their revenue streams and cost to connect to MISO transmission,” he said.

Some stakeholders asked how the RTO will treat transmission upgrades needed to connect HVDC lines in the interconnection queue.

“They’re not going to have interconnection rights,” Godbole said, adding that the lines will instead connect to the MISO system at a 0-MW status.

Under the changes, MISO will hold discussions with HVDC developers and owners before grid connection to determine whether a line is designed to withdraw or inject energy into the system, Godbole said. The RTO will require upstream generators contracting with injecting lines to procure network resource service through the interconnection queue, subject to system impact studies. Those units will be modeled like MISO’s other network resources, showing up in planning studies. Merchant HVDC customers that have secured injection rights and interconnection customers will share the costs of any needed network upgrades.

Meanwhile, merchant HVDC developers will be required to acquire MISO injection rights or a precertification that the system will be able to reliably handle the capacity and energy from proposed lines at the point of connection. (See “HVDC Interconnection,” MISO Eyes Small Queue Changes, Merchant DC Interconnections.)

Godbole acknowledged that MISO may eventually need to develop a more nuanced connection plan for merchant HVDC lines, but that, for now, it is focused on allowing such lines to connect to the system.