MISO had 126.5 MW of battery storage and needs about 10,000 MW by 2035. What closing the gap could save and what needs to change to get there.
The Midcontinent Independent System Operator runs the grid for 45 million people across 15 states and the Canadian province of Manitoba. According to a 2025 report, it needs to grow its battery storage roughly 500% by 2035 to keep costs and reliability in check.
Right now, it's far off track. The report, from the American Clean Power Association and Aurora Energy Research, found MISO had just 126.5 MW of battery storage online.
Here is how big MISO's storage gap is, what closing it could save, and what needs to change.
How Much Battery Storage Does MISO Need?
MISO needs about 10,000 MW of battery storage by 2035, roughly a 500% increase, according to the American Clean Power Association and Aurora Energy Research. It had just 126.5 MW operating when the report was released, with about 980 MW expected by spring 2026, according to Energy-Storage.news.
The key numbers:
- ●Operating today. 126.5 MW.
- ●Expected by spring 2026. About 980 MW.
- ●Needed by 2035. About 10,000 MW, enough to power 8 million homes during peak demand, according to ACP.
- ●In the queue. About 60 GW of standalone storage projects, according to Utility Dive.
The projects exist. What's missing is the path to get them built and connected.
Storage isn't the only thing waiting. Utility Dive reported MISO's queue also holds about 175 GW of solar and 42 GW of wind. That's far more proposed capacity than the region needs, stuck behind the same interconnection studies and grid upgrades.
Why Does MISO Need So Much Storage?
MISO faces rising demand, retiring power plants, limited transmission, and more extreme weather, all at the same time. Storage helps with each of those pressures.
The main drivers:
- ●Growing demand. Data centers, manufacturing, and electrification are pushing load higher.
- ●Plant retirements. Aging coal and other thermal plants are closing.
- ●Transmission limits. Congested lines cause price spikes and curtailment.
- ●Extreme weather. More frequent heat waves and winter storms stress the grid.
Storage fills gaps when solar and wind output dips. It flattens demand peaks to prevent blackouts and price spikes. And it reduces the need to build generation that only runs a few hours a year.
How Much Could Battery Storage Save MISO Customers?
Aurora's modeling shows battery storage could save MISO customers more than $4.5 billion by 2035 and more than $25 billion in energy costs over two decades, according to Energy-Storage.news.
Without more storage, the report warns, peak prices could reach $159 per MWh or higher by 2035.
Utility Dive, reporting on the same study, described the savings as roughly $27 billion in system costs from adding about 11 GW of batteries by 2035. Either way, the conclusion is the same: storage is one of the cheapest ways to keep MISO reliable.
Storage isn't just backup power. It's one of the cheapest tools a grid has for keeping the lights on.
What Needs to Change for MISO to Build More Storage?
The report calls for fairer market rules for storage, faster interconnection, streamlined permitting, and stronger state targets and procurement.
Recommended reforms, according to Energy-Storage.news:
- ●Market rules. Update rules so storage is paid for the full value it provides.
- ●Interconnection. Speed up the process that connects projects to the grid.
- ●Permitting. Streamline state and local approvals.
- ●State targets. Set storage goals and procurement commitments.
Storage provides several kinds of value at once, including peak shaving, renewable integration, and reliability. Markets that pay for only one of those tend to undervalue batteries. When revenue is uncertain, developers and lenders hold back, even on projects that would save customers money.
How Does MISO Compare to Other Grids?
Other grids show both what storage can do and how policy can speed it up.
Australia's Waratah Super Battery shows what fast-response storage can deliver, acting as a grid "shock absorber." New York's 1 GW bulk storage solicitation shows how to design a program that pays for real grid value.
Nationally, storage hit a record quarter in early 2026. MISO has room to catch up quickly if its rules allow it.
What Else Is MISO Doing About Reliability?
MISO is also expanding transmission, which works alongside storage to move power where it's needed. FERC has approved major MISO transmission expansion, as we covered in what MISO's transmission buildout means for solar.
Transmission and storage aren't either/or. Lines move power across the region, and batteries shift it across hours. MISO needs both, and storage can be in place years before most new lines are finished.
What Does This Mean for Solar Owners in MISO States?
As MISO's grid tightens, solar systems that are working and well maintained become more valuable, especially if paired with storage.
Many commercial systems across the Midwest were installed in the 2010s and are now losing output to aging inverters or degraded panels. Repowering can restore production, and adding a battery can capture peak-hour value.
For more on the process, see what solar repowering involves.
Start With a Ballpark Estimate
If you own a commercial solar system in the Midwest, the value of reliable, well-timed power is going up. Find out what your existing solar project may be worth before deciding whether to repair, repower, or sell.
Sources: Energy-Storage.news, "American Clean Power report says MISO needs 500% rise in energy storage by 2035"; American Clean Power Association, report announcement; Utility Dive, "MISO could save $27B in system costs by 2035 with 11 GW of batteries"
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