MISO's interconnection pipeline contains 68 GW of BESS, but only 5 GW has a signed Generator Interconnection Agreement (GIA). Developers have withdrawn 52% of the 106 GW of BESS requested in MISO's main queue since 2015.

The largest share of the pipeline, 14 GW, is in Michigan. The statewide energy storage target of 2.5 GW by 2029 has drawn interest from developers. But, the study region covering Michigan's Lower Peninsula is full, so new requests there must wait for the next cycle. Illinois also mandates 3 GW of BESS by 2030 under its Clean and Reliable Grid Affordability Act (CRGA).

Natural gas makes up 51% of MISO's newest queue cycle, DPP-2026, and batteries 26%. If built, both could narrow the spreads BESS operators earn by flattening daily price shapes.

Key takeaways

• Michigan's 14 GW makes up 21% of MISO's BESS pipeline, and its DPP-2026 cap is full.
• Only 5 GW of the 68 GW pipeline has a signed agreement, 3 GW of it through MISO's Expedited Resource Addition Study (ERAS).
• Natural gas makes up 51% of the 78 GW submitted to DPP-2026, with BESS second at 26% of the total share.
• If built, DPP-2026's 39 GW of natural gas and 20 GW of BESS would narrow the four-hour top-bottom spread, which weighs most on merchant BESS.
• Developers have withdrawn 52% of the 106 GW of BESS requested in MISO's main queue while 23 GW still faces the second decision point.

14 GW of MISO's BESS pipeline is in Michigan, but its DPP-2026 region is full

Of the 58 GW of BESS with a state listed, 14 GW is in Michigan, the most of any state. Indiana and Illinois have 10 GW each, and Minnesota 7.4 GW.

The Definitive Planning Phase (DPP), MISO's main queue, studies projects in five regions: West, Central, South, East (ATC) and East (ITC). American Transmission Company serves East (ATC), covering Wisconsin and Michigan's Upper Peninsula. ITC Holdings serves East (ITC), covering the Lower Peninsula. Most Indiana and Illinois projects sit in Central, and Minnesota's in West.

DPP-2026, the newest cycle, caps how much each region can admit, measured in requested interconnection MW. Developers filled East (ITC)'s 11 GW cap, which affects new requests only. Of the room left, 9.9 GW, or 86%, sits in Central and East (ATC).

Only 5 GW of the 68 GW pipeline has a signed agreement

MISO has signed 5 GW of BESS agreements. Of those, 3 GW came through the ERAS program and 2 GW through the DPP. Natural gas has 22 GW signed, with 15 GW of it fast-tracked through ERAS.

Of the 63 GW without an agreement, 36 GW is in study, most of it in Phase 2, the second of three DPP study phases. The rest sits outside the DPP study phases: DPP-2026 requests, which have not started study, and surplus requests that reuse capacity at existing sites.

MISO runs its expedited queue, ERAS, in parallel with the DPP. ERAS admits projects that a state regulator confirms meet a load or resource adequacy need, and they must reach commercial operation within three years.

After Cycle 5, only eight Illinois and Michigan retail choice slots of its 68-project limit remain. With those slots limited and ERAS closing in 2027, new BESS requests enter through the DPP or as surplus requests at existing sites.

Natural gas makes up 51% of DPP-2026, with BESS second at 26%

Natural gas makes up 51% of the 78 GW submitted to DPP-2026 as of September 18, up from 2% in DPP-2021 and 34% in DPP-2025.

BESS is second at 20 GW, or 26%. Together, gas and BESS make up 76% of submissions.

The queue has also shrunk and changed mix. DPP-2022 drew 161 GW of submissions, 48% of it solar, against 78 GW for DPP-2026. Natural gas rose from 4.7 GW to 39 GW over those cycles, while solar fell from 77 GW to 6.7 GW. BESS fell from 33 GW in DPP-2022 to 10 GW in DPP-2025, then rose 95% to 20 GW.

Federal tax credits explain much of the solar decline. Under the One Big Beautiful Bill Act, wind and solar lose credits unless under construction by July 4, 2026, or online before 2028. DPP-2026 projects cannot meet either date, while BESS keeps its credit until 2033.

If built, DPP-2026's 59 GW of natural gas and BESS would narrow top-bottom spreads

DPP-2026's 39 GW of natural gas and 20 GW of BESS would both narrow the four-hour top-bottom spread if built. Gas adds supply in the evening peak when solar ramps down, which lowers the top of the spread. BESS charges in low-price hours and discharges at the peak, which lifts the bottom and lowers the top.

Modo Energy's revenue outlook puts a four-hour BESS at $50,000 to $85,000/MW-year from 2027 to 2049, across three scenarios.

The fall in solar offsets part of that narrowing. Solar lowers midday prices, which can widen the spread BESS earns, and DPP-2026 carries 6.7 GW of solar against 77 GW in DPP-2022.

Narrower spreads weigh most on merchant BESS, which earn the spread directly through arbitrage. Projects without a utility contract or state procurement are the most exposed, and they may withdraw if spreads in MISO do not support a merchant case.

Developers have withdrawn 52% of BESS requested in MISO's main queue

Developers have withdrawn 55 GW, or 52%, of the 106 GW of BESS requested in MISO's main queue since 2015. Another 49 GW is still in the queue, so the final withdrawal share can only rise. The other 2 GW has a signed GIA, and MISO's queue export lists none of it in service.

Withdrawals cluster in Phase 2. Of the 154 GW withdrawn across all fuels in Q3 and Q4 2025, 91% left in Phase 2. BESS made up 29 GW, 94% of it in Phase 2.

Developers withdrew 44% of the natural gas requested in the main queue and 58% of the solar, against 52% for BESS.

Decision points are where network upgrade costs are assigned, after which deposits become forfeit. DPP-2025 BESS lost 57% of its 10 GW by April 2026, most of it at its first decision point. A 100 MW BESS posts an $8,000/MW, or $800,000, readiness deposit and forfeits 10% at the first decision point and 35% at the second.

Between 23 GW of batteries, from DPP-2022 and DPP-2023, has yet to pass its second decision point. Each 100 MW that withdraws there forfeits $280,000. Across the 23 GW, approximately $65 million of deposits have been required to secure a spot in the queue.

What does this mean for new projects in the queue?

Michigan's 2.5 GW target is already partly contracted. Projects in the other 82% of its queued BESS need other contracts or merchant revenue, or withdraw. Illinois' 3 GW is split between Ameren Illinois in MISO and Commonwealth Edison in PJM, against 10 GW queued in MISO's Illinois footprint.

New BESS requests in the Lower Peninsula move to DPP-2027, behind the requests already above East (ITC)'s cap. Elsewhere, MISO fills each region's cap sequentially by filing date until applications close on January 15, 2027.