Callisto II Energy Center
406.06 MW storage in Harris, TX · In queue since October 2021 · Proposed COD July 2026
406.06 MW
Capacity
1
Components
Battery
4y 7m
In Queue
IA Executed
IA Status
Signed Dec 2023
Queue → IA
2y 2m
IA → COD
2y 7m
Total Duration
2y 2m
Interconnection request submitted to ISO/RTO
ERCOT uses a serial "connect and manage" approach — fastest among major ISOs.
Typical: 18–30 months (fastest major ISO)
Interconnection agreement executed — binding commitment to build
Typical: 30–60 days (negotiation)
Project under construction
Typical: 6–18 months
Proposed COD: 2026-07-20
The Callisto II Energy Center is a proposed 406.06 MW battery storage project located in Harris County, Texas. The project, developed by Callisto II Energy Center LLC, is interconnected within the ERCOT region under queue ID ERCOT-22INR0558. It entered the queue on October 7, 2021, with a proposed commercial operation date of July 20, 2026. The project's interconnection agreement was executed on December 11, 2023.
The proposed project is linked to the existing Callisto II Energy Center operating plant (EIA ID 68422). Recent news coverage indicates the project has been discussed in the context of grid development.
Generated from interconnection queue and public data sources
State
TX
County
Harris
Grid Region
ERCOT (Texas)
Market
ISO/RTO Member
Developer
Callisto II Energy Center LLC
Utility
—
Entity
ERCOT
Service Type
—
Point of Interconnection
47150 HO Clarke 138kV
Data Source
LBNL + Live
- ISO / RTO
- ERCOT
- Trading Hub
- HB_HOUSTON
- Hub Confidence
- HIGH
- Nearest Node (Estimated)
- PRO_RN
- POI Substation
- H.O. Clarke Substation
This project's market context is estimated from its Point of Interconnection. Hub and node assignments are approximate and based on geographic inference from the POI substation name.
