Data center siting snapshot: Santa Clara County, California

Line miles are measured from the archived HIFLD Transmission Lines layer inside the Census county boundary. Mapped lines are not available capacity.

What the public record shows

The archived HIFLD map records approximately 233.2 miles of 230 kV-and-above transmission line within Santa Clara County, including 40.2 miles at 500 kV or more ^[1]. An additional 363.1 miles of 115–161 kV line are mapped in the area ^[2]. Pacific Gas & Electric and Silicon Valley Power hold the most mapped 115 kV+ line miles ^[3]. Six named line endpoints touching 230 kV+ lines are located inside the county ^[4]. Western Area Power Administration and Pacific Gas & Electric have mapped service territories covering parts of the county ^[5].

No county- or city-level data center moratorium or ordinance is present in the records as of November 9, 2026 ^[6]. At the state level, CAISO has a pending large-load interconnection proposal dated October 28, 2026 ^[7]. Several enacted laws from September 21, 2026, apply to data centers, including SB 887 regarding CEQA ^[8], SB 886 concerning ratepayer protection ^[9], SB 1168 on rate structures ^[10], AB 2383 on electricity requirements ^[11], and AB 1577 on energy and water reporting ^[12].

Drafted by our local model from the numbered facts below, then checked sentence by sentence by a second model and a rules-based check.

Data center rules on record

Rule records come from The MW Desk legislation tracker, which includes rows from the Moratorium Nation dataset by Michael J. Bommarito (CC BY 4.0). Statuses change; confirm with the jurisdiction's own record.

Utilities on record

Western Area Power Administration (Wapa), Pacific Gas & Electric. (HIFLD/EIA-861 territory polygons; approximate and often overlapping.)

Market context on The MW Desk: Silicon Valley.

Sources

1. [1] The archived HIFLD map shows about 233.2 miles of 230 kV-and-above transmission line inside Santa Clara County, CA: 40.2 miles at 500 kV or more, 0.0 miles at 345 kV and 193.0 miles at 230 kV. Source: HIFLD Transmission Lines (archived by SeerAI, CC BY 4.0)
2. [2] The same map shows about 363.1 miles of 115–161 kV line in the county. Source: HIFLD Transmission Lines (archived by SeerAI, CC BY 4.0)
3. [3] Owners of record with the most mapped 115 kV+ line miles in the county: Pacific Gas & Electric, Silicon Valley Power. Source: HIFLD Transmission Lines (archived by SeerAI, CC BY 4.0)
4. [4] 6 named line endpoints touching 230 kV+ lines (usually substations or switchyards) are mapped inside the county. Source: HIFLD Transmission Lines (archived by SeerAI, CC BY 4.0)
5. [5] Retail electric utilities whose mapped service territory covers part of the county include: Western Area Power Administration (WAPA), Pacific Gas & Electric. Territory boundaries are approximate. Source: HIFLD Electric Retail Service Territories (EIA-861 based; archived by SeerAI, CC BY 4.0)
6. [6] Our records hold no county- or city-level data center moratorium or ordinance for Santa Clara County as of 2026-11-09. Source: The MW Desk legislation tracker
7. [7] California state/utility level, CAISO: CAISO large-load interconnection proposal (to FERC by Nov 16). Status: pending, dated 2026-10-28. Source: CAISO: Board advances new procedures for connecting large loads quickly and reliably
8. [8] California state/utility level, California: SB 887 (Ch. 439, 2026): CEQA applies to data centers. Status: enacted, dated 2026-09-21. Source: Governor of California: Newsom signs most comprehensive data center laws in the nation
9. [9] California state/utility level, California: SB 886: California Technology Innovation and Ratepayer Protection Act. Status: enacted, dated 2026-09-21. Source: Governor of California: Newsom signs most comprehensive data center laws in the nation
10. [10] California state/utility level, California: SB 1168: data centers, rate structures (Part of the Sep 21 package. Covers data center rate structures). Status: enacted, dated 2026-09-21. Source: Governor of California: Newsom signs most comprehensive data center laws in the nation
11. [11] California state/utility level, California: AB 2383: electricity, data centers (Part of the Sep 21 package. Covers data center electricity requirements). Status: enacted, dated 2026-09-21. Source: Governor of California: Newsom signs most comprehensive data center laws in the nation
12. [12] California state/utility level, California: AB 1577: data centers, reporting (Part of the Sep 21 package. Energy and water reporting). Status: enacted, dated 2026-09-21. Source: Governor of California: Newsom signs most comprehensive data center laws in the nation