Great Rock BESS
300.9 MW storage in Leon, TX · In queue since November 2022 · Proposed COD December 2027
300.9 MW
Capacity
1
Components
Battery
3y 8m
In Queue
IA Executed
IA Phase
Signed Aug 2024
Queue → IA
1y 9m
IA → COD
3y 4m
Total Duration
1y 9m
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: 2027-12-20
- 2025-03·Black Mountain Energy Storage→esVoltasource
Generation Interconnection Agreement executed between CTT and Black Mountain Energy Storage II
sourceesVolta acquired 150MW/300MWh BESS project from Black Mountain Energy Storage
sourceERCOT MORA listed 2026 COD target (later updated to 2027 in subsequent filings)
sourceThe Great Rock BESS project is a proposed 300.9 MW battery storage project located in Leon County, Texas. The developer is Black Mountain Energy Storage II. It is currently active in the ERCOT interconnection queue as entry ERCOT-25INR0230, with a queue entry date of November 7, 2022, and a proposed commercial operation date of December 20, 2027.
The project's interconnection agreement was executed on August 23, 2024. The point of interconnection is Tap 345kV 46020 Limestone - 967 Gibbon Creek Ckt 18.
Generated from interconnection queue and public data sources
Realization risk from now to commercial operation — financing close, EPC and tax-equity counterparty mix, and COD probability vs the proposed date. The diligence view that determines whether the deal actually closes. Powered by InfraSure's development-stage modeling stack.
See the full development-risk decomposition for this project.
State
TX
County
Leon
Grid Region
ERCOT (Texas)
Market
ISO/RTO Member
Developer
Black Mountain Energy Storage II
Utility
—
Entity
ERCOT
Service Type
—
Point of Interconnection
Tap 345kV 46020 Limestone - 967 Gibbon Creek Ckt 18
Data Source
LBNL + Live
Composite operating-phase risk view — what this asset's risk profile will look like once it commissions. Climate hazards across its operating life, expected generation variability, and offtake counterparty exposure, decomposed into a single decision-grade score. Powered by InfraRisk.
See the full risk decomposition + scenarios for this project.
Forward generation outlook — first-year production estimate and 10-year P50 trajectory, with probabilistic ranges (P10/P50/P90) across weather, demand, and policy scenarios. Powered by InfraSure's generation modeling stack.
See the full forecast + scenario decomposition for this project.
Forward revenue, DSCR projection, and financing-close risk — conditioned on commercial operation. First-year DSCR, 10-year cashflow, and counterparty exposure across price and policy scenarios. Powered by InfraSure's asset cashflow stack.
See the full revenue + DSCR projection for this project.
- ISO / RTO
- ERCOT
- Trading Hub
- HB_SOUTH
- Hub Confidence
- MEDIUM
- Nearest Node (Estimated)
- LEG_LEG_G1
- POI Substation
- Limestone Station
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.
No Ask reports yet for this entity.
Ask about Great Rock BESSForward forecasts, scenario decomposition, and risk-decision tooling for this queue project.
