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Grid scale energy storage going through the roof at PJM, California and Texas markets.

image credit: Rakon Energy LLC
Rao Konidena's picture
Independent Consultant, Rakon Energy LLC

Rao Konidena found Rakon Energy LLC because Rao is passionate about connecting clients to cost-effective solutions in energy consulting, storage, distributed energy resources, and electricity...

  • Member since 2014
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  • Sep 16, 2021

Even though solar continues to dominate, looking at the latest MISO interconnection queue after the end of queue application submission in the 2021 cycle, energy storage is a clear winner.

While PJM's active storage requests more than doubled in 2021 compared to 2020, CAISO's storage quadrupled. These statistics show that FERC Order 841 on energy storage has the intended impact on the transmission grid.

Another key observation that is especially true for the Texas grid operator ERCOT (which does not fall under FERC) is that stand-alone storage is more than 60% of the active requests. If we include solar+storage, then the % jumps to 94%, which shows solar+storage is the popular combination right now with the renewable developer community.

In conclusion, FERC order 841 on electric storage resources provides a clear signal for asset owners to interconnect energy storage.

Matt Chester's picture
Matt Chester on Sep 16, 2021

Another key observation that is especially true for the Texas grid operator ERCOT (which does not fall under FERC) is that stand-alone storage is more than 60% of the active requests

This is pretty incredible-- does this mean that many storage projects are participating in the markets on their own? Any intel on the distribution of sizes of the projects? 

Rao Konidena's picture
Rao Konidena on Sep 16, 2021

In Texas, for stand-alone storage, according to the data posted by ERCOT on their website, the min size is 24 MW and the max size is 500 MW. Yes, storage is participating in the ERCOT wholesale market.

Bob Meinetz's picture
Bob Meinetz on Sep 16, 2021

It's a shame, Rao, that so many have been deluded into believing bulk energy storage is making a contribution in the fight against climate change.

Bulk Energy Storage Increases United States Electricity System Emissions

"Bulk energy storage is generally considered an important contributor for the transition toward a more flexible and sustainable electricity system. Although economically valuable, storage is not fundamentally a “green” technology, leading to reductions in emissions. We model the economic and emissions effects of bulk energy storage providing an energy arbitrage service. We calculate the profits under two scenarios (perfect and imperfect information about future electricity prices), and estimate the effect of bulk storage on net emissions of CO2, SO2, and NOx for 20 eGRID subregions in the United States. We find that net system CO2 emissions resulting from storage operation are nontrivial when compared to the emissions from electricity generation, ranging from 104 to 407 kg/MWh of delivered energy depending on location, storage operation mode, and assumptions regarding carbon intensity. Net NOx emissions range from −0.16 (i.e., producing net savings) to 0.49 kg/MWh, and are generally small when compared to average generation-related emissions. Net SO2 emissions from storage operation range from −0.01 to 1.7 kg/MWh, depending on location and storage operation mode."

Rao Konidena's picture
Rao Konidena on Sep 24, 2021


You bring up a good point in terms of policies to enable energy storage.

If the intent is to reduce carbon emissions and other harmful emissions, storage should discharge when emissions are higher not lower.

Bob Meinetz's picture
Bob Meinetz on Sep 24, 2021

Rao, it's unfortunate that the study above is behind a $40 paywall. But because it's printed in the peer-reviewed publication of a non-profit organization, the American Chemical Society, I spent the forty bucks and wasn't disappointed.

The biggest takeaway is this: charging batteries directly from the output of a solar or windfarm isn't profitable. That, combined with the fact charging from a grid mix always increases carbon emissions, basically eliminates any possibility of reducing overall emissions with grid-scale storage.

Any "solution" to a problem that makes the problem worse is no solution at all.

Jim Stack's picture
Jim Stack on Sep 17, 2021

Storage can help any power source. As you know even COAL plants have to run at full power as they take so long to ramp up and down they can't adjust to the changing load of the users. They GRID has needed storage since it was created. Some forma like pumped hydro storage help but as still very slow to respond to the changing needs. Todays no toxic long lasting lithium battery storage responds in a nano second and is very valuable. New chemistries and anode cathode materials are reducing cost while improving the already long life of the cells.   

     Batteries storage is the best thing to happen to the GRID in 100 years. 

Rao Konidena's picture
Rao Konidena on Sep 25, 2021

I agree Jim. Storage is the best thing that happened to the electric grid in 100 years.

Just take these instances


After finding that their three Distributed Energy Storage Initiative (DESI) systems discharged during the summer peak demand hours, helping Southern California Edison (SCE) avoid distribution outages, SCE signed seven contracts worth 770 MW of battery storage systems to meet future reliability needs. “The three systems were discharged for two hours starting around 5 p.m. on Aug. 15, when the outages took place, and on Aug. 17, to help avoid further outages. The systems continue to discharge each day starting around 5 p.m.” SCE Blog


Xcel Energy – Colorado mentioned that the Panasonic battery successfully provided islanding and backup power during 2 feeder outages in their report to the Colorado PUC. Xcel Energy's 2019 Annual Report to the Colorado Public Utilities Commission Regarding the Innovative Clean Technology Program, Docket # 09A -015E ,

Sterling Municipal Light Department in Massachusetts's battery can provide backup power for upto 12 days for Sterling's critical facilities. Page 38, CESA report

Joe Steinke's picture
Joe Steinke on Sep 23, 2021

PG&E just took 40% of our state battery storage capacity offline due to overheating.  Barely missed another battery fire.  Scorched batteries, melted wires.....

Rao Konidena's picture
Rao Konidena on Sep 24, 2021

Yes, this overheating issue is something the industry is grappling with. First, the Arizona Public Service (APS) battery fire incident. And now this PG&E fire incident.


Bob Meinetz's picture
Bob Meinetz on Sep 24, 2021

Joe, Vistra's Moss Landing Storage facility was storing the direct output of Moss Landing Power Plant, the fifth-largest gas plant in California, and doubling its carbon footprint from efficiency losses - in effect, turning it into a coal plant.

From an environmental standpoint, a battery fire that took Vistra's storage permanently out of commission would have been the best possible outcome. It would be expensive, however, and emissions from burning batteries might be a problem - temporarily.  :-)

Rao Konidena's picture
Thank Rao for the Post!
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