Dive Brief:

• Distributed energy resources in the Midcontinent Independent System Operator footprint grew to 12.5 GW this year as residential DER jumped 63% from 2022, according to an Organization of MISO States, or OMS, report released Monday.
• For the first time, there was more distributed solar, at 5.5 GW, than demand response in MISO, at 5.1 GW, OMS found in its annual utility survey on DERs.
• “DER growth continues at a steady pace throughout MISO,” said Marcus Hawkins, executive director for OMS, which represents state utility regulators in the grid operator’s footprint. The nearly 1 GW increase in residential distributed resources is “really interesting” because it is the type of DER that grid operators have the least amount of visibility into, he said Monday.

Dive Insight:

Residential DER is making up a growing share of MISO’s distributed resources, according to the survey of utilities in MISO. Residential DER — with nearly 3 GW — made up almost a quarter of the grid operator’s DER resources this year, up from 11% — or 0.4 GW — in 2019.

This summer, on several extremely hot days, MISO over-forecasted its load, Tyler Huebner, a commissioner on the Wisconsin Public Service Commission, said during a presentation on the survey.

In its forecasts, MISO may not have accounted for power production from DERs that aren’t registered with the grid operator, which are largely residential resources, Hawkins said. Eventually, those resources will be accounted for in grid planning because they will be part of the historical load, but it doesn’t appear that utilities or MISO are actively projecting and forecasting the effects of unregistered DERs, he said.

Nearly all the DER increases in MISO this year occurred in its zones 1 and 7, which mainly cover Minnesota and North Dakota, and Michigan, respectively, according to OMS. The two zones have almost half of MISO’s DER capacity: Zone 1 has 3.4 GW, or 27% of MISO’s DER capacity, and Michigan has 2.7 GW, or 21% of the DER capacity, the survey found.

Solar resources account for 44% of MISO’s DER capacity, followed by demand response at 41% and internal combustion at 5%, OMS said. Hawkins cautioned that the survey likely undercounts demand response resources.

Roughly 70% of survey respondents expect DER capacity in their service territories to continue growing, partly driven by corporate sustainability goals, falling costs for distributed resources and the potential to participate in MISO’s wholesale markets.

So far, most survey respondents don’t expect electric vehicle growth will affect the transmission system, but most utilities said they were incorporating DERs into their transmission planning, according to the survey.

The survey comes as grid operators like MISO are preparing to implement the Federal Energy Regulatory Commission’s landmark Order 2222, which requires aggregated DERs to be able to participate in wholesale power markets. However, MISO doesn’t plan to launch market rules for aggregated resources until 2030.

Some survey respondents told OMS they were waiting on the final MISO market process before moving forward with DER activities.

In response to a question about planning for future DER implementation, the most common response was a need to align MISO, state and FERC policy and technical requirements.

MISO operates the grid and wholesale power markets across 15 central U.S. states and in Manitoba, Canada.