MISO on Thursday told stakeholders it had removed a 10-MW size limit on aggregations of distributed energy resources (DERs) from its FERC Order 2222 compliance proposal.

During a Distributed Energy Resources Task Force (DERTF) meeting, DER Program Manager Kristin Swenson said MISO removed the limit and will not propose a size limit on either aggregations or a single asset within an aggregation.

The RTO surprised stakeholders late last year by announcing the 10-MW limit. It has been on record multiple times saying it wouldn’t limit the size of aggregations in its markets under Order 2222.

Several stakeholders attending a late November DERTF meeting said it was the first they heard of a maximum threshold on DER aggregations. Staff cited market power concerns and simplified generation outage coordination for setting the size limit.

Swenson said MISO may have to revive discussions on size limits if unusually large aggregations seek wholesale market access. She said staff expects most aggregations to be relatively small but said it’s possible that an 80-MW wind farm on the distribution system could expect to participate in the markets without first entering the generator interconnection queue.

The grid operator plans to rely on its electric storage resource participation model to let DER aggregations participate in the wholesale market. It also said aggregations must be limited to a single pricing node and must self-commit. MISO has said it will not provide output forecasts for the aggregations. (See MISO Draws on Storage Model for DER Aggregations.)

The RTO is currently drafting the compliance filing.

“We’re in the crunch time here. There’s going to be a lot of tariff language,” Swenson warned stakeholders late last year.

Staff has said they don’t expect the Order 2222 compliance to cover all DER applications in the wholesale market.

“We have a lot to learn about DERs and how they will participate in the market,” Swenson said.

MISO is also contemplating whether it needs a forum to discuss DERs after it achieves FERC compliance.  

The DERTF is slated to sunset July 31. Stakeholders are debating extending the sunset date by a year or transitioning it into a working group to address evolving and growing DER participation.

MISO says stakeholders can modify the group and reestablish a charter that doesn’t explicitly mention Order 2222 compliance once the RTO has a compliance ruling. It is accepting stakeholder input on whether to maintain a dedicated DER stakeholder group.

WEC Energy Group’s Chris Plante predicted more DER issues will need to be discussed once states have more assets on their distribution systems.

MISO legal counsel Michael Kessler said he doesn’t see a need for stakeholder work on Order 2222 or DER aggregation participation until FERC’s ruling.

“We’re going to be in a hold mode waiting on FERC,” Kessler said.