| Substation | Voltage (kV) | Distance (mi) | Best-Case Offtake (MW) | Worst-Case Offtake (MW) | Status |
|---|---|---|---|---|---|
| CANEY | 138 | 3.7 | 838 | 188 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE |
| Tenaris Substation | 138 | 4.4 | 148 | -5,673 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| VAN VLECK | 69 | 4.6 | 30 | -5,419 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Bay City | 138 | 7.7 | 148 | -5,432 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Magill Substation | 138 | 8.1 | 107 | -5,685 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| OLD OCEAN 2 | 138 | 8.7 | — | — | No Published Offtake |
| LINNVILLE | 138 | 8.8 | — | — | No Published Offtake |
| Phillips No 5 | 138 | 8.9 | 117 | 48 | Positive (Stable) |
| Phillips No 2 | 138 | 8.9 | 130 | 47 | Positive (Stable) |
| OLD OCEAN | 138 | 8.9 | — | — | No Published Offtake |
| Old Ocean | 138 | 9.0 | 117 | 54 | Positive (Stable) |
| FM 524 Substation | 138 | 9.0 | 385 | -50,000 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| SWEENY COGENERATION | 138 | 9.1 | — | — | No Published Offtake |
| Phillips No 3 | 138 | 9.3 | — | — | No Published Offtake |
| HAWKINS POI | 345 | 9.3 | 1,480 | -5,131 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| BAY CITY | 69 | 9.5 | — | — | No Published Offtake |
| REFUGE | 345 | 9.6 | 1,195 | -5,192 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| SWEENY | 138 | 11.0 | 376 | -14 | Positive (Stable) |
| CHALMER | 138 | 11.6 | 107 | -6,005 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Sargent Substation | 69 | 12.7 | 23 | -4,977 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Celanese | 138 | 12.7 | 116 | -4,499 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Esperanza | 138 | 13.3 | 117 | -4,475 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| MARKHAM | 69 | 13.7 | 84 | -5,266 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Wadsworth | 138 | 14.2 | 107 | -4,827 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Conoco | 138 | 14.3 | 131 | -134 | Positive (Stable) Constrained under worst scenario |
| ISSAC PV | 138 | 14.4 | 131 | -134 | Positive (Stable) Constrained under worst scenario |
| PLEDGER | 138 | 15.5 | 578 | 161 | Positive (Stable) |
| WEST COLUMBIA 2 | 138 | 15.7 | — | — | No Published Offtake |
| Clemons Dome | 138 | 16.3 | 59 | 56 | Positive (Stable) |
| Clemons Tap | 138 | 16.6 | 60 | 57 | Positive (Stable) |
| South Texas Project Pump Substation | 138 | 16.6 | 77 | -4,293 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Gulf Star | 138 | 16.8 | 578 | 90 | Positive (Stable) |
| West Columbia Main | 230 | 16.8 | 1,116 | -50,000 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| West Columbia Local | 138 | 16.8 | 114 | -50,000 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| NORTH COLUMBIA | 138 | 16.9 | — | — | No Published Offtake |
| WEST COLUMBIA | 138 | 16.9 | — | — | No Published Offtake |
| Franklins Camp | 138 | 17.1 | 23 | -4,802 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| BRAZORIA | 138 | 17.2 | 439 | -13 | Positive (Stable) |
| BAILEY | 345 | 17.2 | 1,922 | -4,658 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| SOUTH TEXAS PROJECT TAP | 138 | 17.4 | 117 | -4,293 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| South Texas Project Switchyard | 345 | 17.4 | 1,954 | -4,293 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Clemville North Substation | 69 | 17.8 | 78 | -5,833 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Tres Palacious | 69 | 18.1 | — | — | No Published Offtake |
| Salt Dome | 69 | 18.1 | 25 | -6,229 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| South Clemville | 69 | 18.2 | 24 | -6,042 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| NEW GULF | 138 | 18.4 | 521 | -7,587 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| Dow Pump Substation | 69 | 18.4 | 43 | 43 | Positive (Stable) |
| TAP301963 | 138 | 18.5 | — | — | No Published Offtake |
| SOUTH LANE CITY | 138 | 18.6 | 682 | -6,411 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
| CLEMVILLE 2 | 69 | 18.7 | — | — | No Published Offtake |
| JULIA | 345 | 19.0 | 1,819 | -8,850 | Positive (Sensitive) ⚠ SCENARIO SENSITIVE Constrained under worst scenario |
Offtake = ERIS (energy-only load rights), ERCOT scenarios 2027–2035. "Scenario Sensitive" = best-to-worst spread >500 MW. "Constrained under worst scenario" = worst-case Offtake < −100 MW.
The the site has 39 of 51 substations (≥69 kV) within 20 miles showing positive Offtake headroom in at least one planning-study scenario. The overall envelope ranges from -50,000 MW (worst-case) to 1,954 MW (best-case) across all POIs and scenarios.
27 of 51 POIs exhibit scenario sensitivity (best-to-worst spread >500 MW), meaning deliverability depends materially on operating conditions. The most volatile POIs include the 345 kV stations (HAWKINS POI, BAILEY, JULIA, South Texas Project Switchyard) where the spread between best-case and worst-case exceeds several thousand MW.
12 substations within the radius have no published Offtake data. These are typically lower-voltage distribution substations outside the ISO planning study scope.