In June 2024, ERCOT experienced its largest-ever monthly increase in new battery energy storage capacity.
649 MW of rated power - with 1,040 MWh of energy capacity - became commercially operational across five sites.
This followed the record-low month of May. No new batteries began commercial operations in May - the first month this had happened since October of last year.
![](https://images.storychief.com/account_26864/june-buildout-graph-1_b98f64db99affaaded57734da02d99f4_800.png)
This brings the total rated power of commercially operational BESS to 5.3 GW. Since the beginning of 2023, this figure has grown by 2.7x.
Check out the video below to see an executive summary of this report.
Which battery energy storage systems reached commercial operations in June 2024?
June wasn’t only the largest-ever increase in rated power and energy capacity in ERCOT. It also saw the commissioning of the largest-ever battery projects - both in terms of rated power and energy capacity.
![](https://images.storychief.com/account_26864/june-buildout-graph-2_df8454323a93e58e699e5ad356197048_800.png)
ENGIE’s Five Wells project became the largest battery by rated power in ERCOT at 221 MW. This surpassed ENGIE’s 206 MW Libra BESS, which came online in April of this year.
Additionally, Plus Power completed two projects that now share the record for the largest energy capacity of any battery in ERCOT:
- Ebony, located just north of San Antonio,
- and Anemoi, near McAllen in the Rio Grande Valley
Both are ~2-hour systems with 400 MWh energy capacities.
This means that Plus Power systems now make up 20% of ERCOT’s total installed battery energy storage capacity (MWh). Plus Power overtook Jupiter Power with the installation of these two new systems.
![](https://images.storychief.com/account_26864/image_266828f79e60741dd3e9f41fc38f7b9f_800.png)
As an aside, Eolian’s Madero Unit 1 and Unit 2 are located at the same site, and if aggregated as one single site, would be the largest site in ERCOT by energy capacity at 500 MWh. However, as these two units operate independently of one another (as per the ERCOT data that Modo uses to populate the ERCOT BESS Index), they are therefore counted as two separate assets in this analysis.
Elsewhere, Hunt Energy Network continued to add to their network of one-hour, 9.9 MW resources. In June, Farmersville West 1 and Mainland became commercially operational. This brings Hunt’s total number of battery energy storage systems in commercial operations up to 24.
Buildout continues to trend toward two-hour resources
As total rated power grew to 5.3 GW in June, total energy capacity hit 7.4 GWh. This brings the average duration of battery energy storage systems in ERCOT to 1.41 hours.
![](https://images.storychief.com/account_26864/image_52b7344d315853f0ff0807125c52d41a_800.png)
This is up from 1.38 in April, 1.34 at the beginning of the year, and 1.22 at the beginning of 2023.
Similarly, systems with a duration of more than 1.5 hours now make up 39% of the total rated power in ERCOT. This has grown from 26% just twelve months ago.
![](https://images.storychief.com/account_26864/image_446f1cea9d16fc96c9120181756dbc1f_800.png)
Longer-duration systems can better capture revenues from Energy arbitrage. They’re also more suited to some Ancillary Service markets - like the ERCOT Contingency Reserve and Non-Spinning Reserve Services.
This explains the shift toward two-hour systems. The proportions of revenues earned via Regulation and Responsive Reserve will decrease - as more batteries coming online saturate those markets.
How are the size and location of battery energy storage systems changing?
In April 2024, the first 200+ MW battery in ERCOT reached commercial operations. In June, three more new batteries crossed that same threshold.
We hinted that this would happen in our last buildout update - as the size of ERCOT batteries continues to grow.
This has rapidly brought the proportion of rated power from 200+ MW batteries up from 0% to 15% in a short three months.
![](https://images.storychief.com/account_26864/image_1e24cc069703a08145406fe09aa4d067_800.png)
The average size of battery energy storage systems in ERCOT now stands at 42 MW. This represents a 31% increase from the 32 MW average from exactly twelve months ago.
Another shifting trend is location.
Historically, the West Load Zone has seen the highest rate of deployment for battery energy storage systems across ERCOT.
In fact, as recently as January of this year, batteries located in the West represented 42% of the system's total rated power.
![](https://images.storychief.com/account_26864/image_05acb08234e5180d1a3131099e1865b8_800.png)
However, the percentage has now fallen to 35% - as batteries are now being deployed faster across the rest of the state.
Modo subscribers can read the rest of the report below - to learn more about what we expect to happen in the next 18 months. You can also download the data behind this report.
What does the future hold?
The ERCOT interconnection queue indicates that many of the trends emerging thus far in 2024 are expected to continue.
While attrition rates for projects are substantial (and commissioning delays are inevitable), battery buildout is still happening very quickly.