By Amanda Durish Cook

FERC is asking RTOs for information on aggregated distributed energy resource portfolios in their wholesale markets — the first significant movement in a possible rulemaking on DER in more than a year.

On Sept. 5, FERC’s Office of Energy Policy and Innovation sent identical letters to all the RTOs and ISOs seeking data on their existing aggregated DER interconnections (RM18-9).

“Commission staff is interested in further exploring the interconnection of distribution-connected DERs, in particular those that participate or will participate in DER aggregations for the purpose of providing wholesale service in markets operated by [RTOs/ISOs],” FERC said.

The commission asked for responses by Oct. 7, which will be followed by a 30-day comment period.

The 11-question list asks RTOs to provide data or estimates on the number of DERs in each footprint that directly participate in wholesale markets versus the DERs that don’t participate. FERC also inquired about RTOs’ coordination with state and local leadership about DER interconnection processes.

More detailed questions delve into each RTO’s “step-by-step” interconnection process for DERs and whether the process differs if DERs are eligible qualifying facilities or are behind a retail customer meter. FERC also asked how an aggregation of DERs located at multiple points of interconnection are studied, whether RTOs have interconnection studies for bidirectional service and how an RTO would handle a study for individual, already-interconnected DERs that wish to aggregate from separate points on the grid. Finally, the commission asked how the RTOs manage DERs aggregating from both FERC-jurisdictional and non-jurisdictional distribution facilities and requested the number of distribution facilities subject to an open access transmission tariff.

RTOs and ISOs this week said they were working to prepare data submittals.

Spokesperson Meghan Sever said SPP is working to provide FERC with “as much of the requested detailed DER data as possible” by the early October deadline.

MISO said it is working with the Organization of MISO States — which has developed its own DER estimates — and its stakeholder community to understand DER interconnection across the transmission and distribution interface.

“MISO has assembled a team of its subject matter experts who are reviewing the specific data requests and developing information to provide the requested information,” spokesperson Allison Bermudez said in an email to RTO Insider. “We will continue to coordinate with OMS and other stakeholders as we evaluate our responses.”

ISO-NE also said it was working to comply with the request. NYISO said it wouldn’t comment on preparations beyond its “official response to FERC.”

AEE Welcomes Movement

Leadership at Advanced Energy Economy, a D.C.-based trade association with members who develop and use DERs, took the data requests as a good omen. “We think it’s a good sign that the commission continues to dig into the issue and put some focus on it,” said AEE Managing Director and General Counsel Jeff Dennis, who leads the group’s wholesale markets advocacy.

But Dennis warned that the newest action in the DER docket now leaves any new rule waiting at least until November, and probably longer. With a draft DER rule still in a holding pattern, AEE released a white paper Sept. 5 outlining five case studies where DERs can be beneficial in wholesale markets. Dennis said the paper illustrates how DERs can provide service in wholesale markets to the benefit of consumers and the grid.

“As we await a final rule from FERC, there is a lot of discussion of the challenges to [DER participation] in wholesale markets. We wanted to focus on the benefits and the fact that this is already happening,” AEE Director Caitlin Marquis said of the five scenarios, which include managing demand or load with solar generation, battery storage, electric vehicle fleets and microgrids.

The case studies include a microgrid that can participate in wholesale energy and demand response markets to bolster vulnerable points on the grid or help during extreme weather; aggregated battery storage installations used for demand charge management; and electric vehicle fleets that are responsive to demand. The paper also highlights commercial solar generation and storage installations used to meet corporate sustainability goals and reduce wholesale market load and aggregated residential solar/storage facilities that have cleared ISO-NE’s forward capacity auction.

“This is what we could have more of if there were rules in place,” Marquis said, noting that some of the case studies are based on actual DER setups from AEE’s member companies.

Dennis also said there’s no harm in RTOs doing more work now to prepare for a DER rule.

“What we really want to see is additional efforts by RTOs and their stakeholders to look at how DERs will contribute to the wholesale markets in the future. Many RTOs are starting to do this now, and we hope others will follow suit,” Dennis said. “What’s really going to be needed beyond that though is RTOs taking a full look at their markets and the services that DERs can provide in those markets … and then ensuring that there are market participation pathways for them to do that.”

Dennis said AEE staff is also meeting with some RTOs to emphasize the benefits of aggregated DERs and discuss operational characteristics and implications for long-term system planning.

“Their experience so far is with large, central station power plants,” Dennis said of the RTOs. “We want to help them shift their thinking and approaches to prepare for the grid of the future, which will include many more distributed resources.”