Bosque Switch is identified on ERCOT planning maps as a critical node in Central Texas. It offers L2D2's hyperscale data center development unparalleled direct on-site access to both 345 kV and 138 kV transmission lines. Unlike typical major node developments in regions such as DFW or Austin, which often require extensive right-of-way acquisition, significant infrastructure upgrades, or new transmission line construction, the Bosque Switch allows L2D2 to connect directly to existing lines on-site. This unique characteristic, detailed in Oncor Bosque-Elm Mott project filings, significantly reduces development timelines, costs, and complexity, providing a distinct competitive advantage.
The Bosque Switch (Thad Hill Substation) is recognized as one of ERCOT's most strategically important nodes in Central Texas, primarily utilizing 345 kV for interconnection with 138 kV serving as redundancy and operational flexibility [ERCOT's 2024 transmission planning report]. This critical infrastructure anchors multiple high-voltage transmission corridors, connecting Waco, Temple, Venus, and Lake Creek, thereby establishing a robust power backbone that directly enables large-load developments throughout the region. Compared to congested major nodes like DFW or Austin, the Bosque Switch offers significantly reduced queue times and high MW availability, crucial for rapid deployment.
The facility's strategic positioning makes it ideal for supporting the L2D2 (Lacy Lakeview Data District) development in Elm Mott. Located at Katy Rd, Elm Mott, TX, the L2D2 site uniquely benefits from having existing 345 kV and 138 kV transmission lines passing directly through the property [Oncor Bosque-Elm Mott project filings]. This eliminates the need for any new transmission line construction or right-of-way acquisition, providing unparalleled opportunities for immediate, scalable interconnection for hyperscale data center operations and high-density GPU compute workloads. This direct on-site access leverages both voltage levels for ultra-low-loss energy delivery (with losses below 1% for 345 kV) and operational flexibility, all without the usual timelines, costs, or complexities associated with new infrastructure development [ERCOT transmission studies on Bosque Switch interconnectivity].
The convergence of existing, on-site transmission capacity across multiple voltage levels, coupled with generation resources and a strategic location, positions L2D2 as a foundational asset for Central Texas' grid infrastructure and next-generation industrial development, supports N-1 with enhanced redundancy approaching N-2 performance for critical loads.


Robust connectivity, including existing dual 345 kV circuits to Lake Creek, single 345 kV circuits to Temple and Elm Mott, dual 345 kV Venus circuits (A & B), and critical 138 kV interconnections that already traverse the L2D2 development site. This eliminates the need for new transmission line construction or right-of-way acquisition.
[Source: ERCOT Planning Maps, Oncor Bosque-Elm Mott Project Filings]

Independent dual buses per voltage level (North and South 345 kV and 138 kV buses) enable complete switching flexibility and fault isolation without transmission capability loss across both critical voltage levels, complementing the existing on-site transmission infrastructure.
[Source: Oncor Substation Design Documentation]

Thad Hill Power Plant's 807 MW combined-cycle gas facility feeds directly into the switchyard infrastructure, providing immediate access to generation alongside the existing transmission lines at L2D2.
[Source: EIA Plant Data, ERCOT Generation Interconnection Queue]

Junction point between ERCOT's North and South transmission zones serving as a critical stability anchor. This position facilitates direct and immediate connectivity, leveraging lines already crossing the L2D2 site.
[Source: ERCOT Transmission Studies, ERCOT's 2024 transmission planning report]
The Bosque Switch features a comprehensive multi-circuit configuration ensuring unparalleled redundancy for Central Texas operations. Crucially, these lines already pass directly through the L2D2 site, meaning no new construction or right-of-way acquisition is needed for direct interconnection.
[Source: ERCOT Planning Maps, Oncor Bosque-Elm Mott Project Filings]
Bosque's independent dual buses per voltage level (North and South 345 kV and 138 kV buses) represent a best-in-class substation design, critical for transmission backbone applications. This robust architecture, combined with the existing on-site transmission lines at L2D2, drastically simplifies and accelerates interconnection.
[Source: Oncor Substation Design Standards]
Direct access to existing 345 kV and 138 kV lines on-site means no new transmission line construction or right-of-way acquisition is needed, drastically reducing interconnection timelines and costs for L2D2. This is confirmed by ERCOT's 2024 transmission planning report and Oncor filings.
Multi-path redundancy via existing on-site architecture, combined with Bosque's independent dual-bus configuration per voltage level, enables an architecture supports N-1 with enhanced redundancy approaching N-2 performance for critical loads and supporting double-contingency scenarios, ensuring near-zero downtime for AI and hyperscale operations.
Rapid scalability from initial 150 MW energization through full 925 MW buildout capacity, leveraging pre-existing 345 kV infrastructure for primary feeds and 138 kV for flexibility, minimizes voltage transformation losses and supports high-density compute requirements.
L2D2's direct connection in the Bosque–Elm Mott corridor offers expedited interconnection queue processing and higher MW allocation probability compared to congested nodes, serving as a critical stability anchor between ERCOT's North and South zones, further validated by ERCOT congestion reports.
L2D2's power infrastructure strategy primarily leverages the existing on-site 345 kV transmission lines across all development phases, with 138 kV lines serving for redundancy and operational flexibility, maximizing efficiency and minimizing technical risk by connecting directly to available infrastructure.
L2D2's location provides direct interconnection to existing 345 kV and 138 kV transmission lines already traversing the site. This advantage, validated by ERCOT's 2024 transmission planning report, eliminates the need for new transmission line construction, ensuring immediate access to high-capacity power, significantly reducing construction timelines, and drastically lowering interconnection costs compared to sites requiring new line builds or extensive right-of-way.
With both 345 kV and 138 kV transmission lines already traversing the L2D2 site, as confirmed by Oncor filings, the need for costly and time-consuming right-of-way acquisition and new infrastructure construction is eliminated. This foundational advantage significantly reduces project costs, accelerates the development timeline by bypassing new line buildouts, and streamlines regulatory approvals due to minimal external impact.
Independent 345 kV and 138 kV transmission paths, already present on-site and reflected in ERCOT transmission studies, provide multiple routing options for redundant feeds to L2D2's private substation. This direct connection allows for immediate power rerouting capabilities via existing lines during congestion or maintenance, ensuring superior reliability and supporting double-contingency scenarios without additional infrastructure development.
All development phases are primarily designed to utilize the existing on-site 345 kV transmission for high efficiency and minimal losses. The 138 kV lines also present on-site offer additional interconnection flexibility. This allows for direct and rapid scalability from initial 150 MW energization through full 925 MW buildout capacity, leveraging infrastructure already in place, as supported by Oncor Bosque-Elm Mott project filings.
The independent dual-bus structures at Bosque, supporting both 345 kV and 138 kV, combined with L2D2's direct connection to existing dual-feed lines on-site, enables an architecture supports N-1 with enhanced redundancy approaching N-2 performance for critical loads and supporting double-contingency scenarios. This is paired with local on-demand generation to ensure near-zero downtime for high-density compute operations, without requiring new transmission line construction, as demonstrated in ERCOT Grid Code and NERC Reliability Standards.
The Thad Hill plant's synchronous generators provide critical voltage regulation and system inertia, stabilizing the network against fluctuations from renewable sources—essential for GPU-driven campus operations. This support is directly accessible via the existing on-site 345 kV and 138 kV systems, leveraging established grid infrastructure and minimizing voltage transformation losses due to the direct high-voltage connection, as confirmed by EIA Plant Data and ERCOT Generation Interconnection Queue.
Compared to the often-congested DFW and Austin nodes, the Bosque–Elm Mott corridor offers faster interconnection queue processing with a higher probability of full requested MW allocation approval. This is significantly bolstered by L2D2's ability to directly connect to existing 345 kV and 138 kV networks already present on the site, bypassing new line construction delays and leveraging available capacity identified in ERCOT's 2024 transmission planning report.
This section provides a detailed comparison of the Bosque Switch interconnection point with other major ERCOT nodes, highlighting why Bosque offers superior advantages for hyperscale and AI compute operations, particularly given the existing 345kV and 138kV lines already traversing the L2D2 site. All primary interconnections utilize 345 kV; 138 kV serves as redundancy and operational flexibility.
Below is a comparative overview of key transmission infrastructure metrics for Bosque Switch and alternative ERCOT nodes, demonstrating Bosque's robust and efficient connectivity. This data is derived from ERCOT planning maps and public utility filings, including ERCOT's 2024 transmission planning report and Oncor Bosque-Elm Mott project filings [1].
Bosque boasts 6+ independent 345 kV circuits, offering significantly higher reliability and capacity compared to the typical 2-4 circuits found in DFW and Austin nodes, as detailed in ERCOT's 2024 transmission planning report[.
Both 345kV and 138kV transmission lines already traverse the L2D2 site, enabling direct connection and eliminating the need for new transmission line construction or right-of-way acquisition. This drastically reduces costs and accelerates development timelines, unlike most other ERCOT nodes, as confirmed by Oncor Bosque-Elm Mott project filings.
The Central Texas corridor around Bosque experiences lower grid congestion compared to the heavily loaded DFW and Austin metropolitan areas, allowing for more reliable power delivery and faster interconnection queue processing, as validated by ERCOT congestion reports[.
Bosque benefits from direct connection to the 807 MW Thad Hill plant, providing critical local generation capacity. This offers a significant advantage over sites reliant on remote generation sources, contributing to enhanced grid stability, as outlined in ERCOT's 2024 transmission planning report.
Understanding the timeline for interconnection is crucial for project planning. Bosque offers a significantly faster path to energization due to existing on-site infrastructure and lower queue congestion compared to major metropolitan areas.
The economic benefits of choosing Bosque extend beyond just the initial interconnection, impacting long-term operational costs and project viability, particularly due to the existing on-site transmission lines.
This chart visually summarizes the critical differences, making it clear why Bosque is the optimal choice for L2D2.
A thorough understanding of voltage hierarchy, transmission loss modeling, circuit capacity, and dynamic stability is crucial for ensuring the reliability and efficiency of the L2D2 hyperscale and AI compute operations. This section details these critical technical aspects.
L2D2's primary interconnections will leverage the 345 kV backbone for robust power delivery. The 138 kV infrastructure will provide redundancy and operational flexibility, serving specific secondary roles:
Accurate modeling of transmission losses is vital for optimizing operational efficiency and minimizing energy waste. The table below illustrates expected transmission losses for different scenarios and load levels, showcasing the efficiency of 345 kV transmission compared to higher losses typically observed for 138 kV lines or longer distances to congested nodes like DFW or Austin:
Factors significantly affecting transmission losses include conductor size, actual loading levels, and the effectiveness of reactive compensation. These figures highlight the substantial advantage of using 345 kV for high-MW loads to minimize energy dissipation, a key benefit compared to locations requiring longer transmission lines or reliance on 138 kV for primary feeds.
These considerations underscore the technical rigor required. Detailed power system studies, including transient stability and short-circuit analyses, would be required for final design validation to ensure optimal performance and compliance with ERCOT standards, aligning with findings from ERCOT's 2024 transmission planning report.
Technical schematic from THSES documentation illustrating dual generating units (U1, U2), independent dual 345 kV and 138 kV bus configurations (North and South), and direct access to existing transmission lines at the L2D2 site, including circuits to Lake Creek, Temple, Elm Mott, and Venus. (Ref: Oncor Bosque-Elm Mott project filings)
Regional overlay demonstrating direct on-site access to existing primary 345 kV and secondary 138 kV transmission lines at the L2D2 site. This eliminates the need for new corridor development, leveraging the immediate presence of critical infrastructure for direct, low-complexity connection. (Ref: ERCOT 2023 Planning Maps)
Comprehensive visualization of on-site 345 kV and 138 kV transmission infrastructure, enabling direct interconnection. This architecture supports redundant feed configurations and seamless integration with existing dual-voltage Bosque Switch infrastructure for immediate and phased capacity expansion, without requiring new transmission line construction. (Ref: ERCOT Interconnection Standards)
The L2D2 site in Elm Mott benefits from direct access to existing 345 kV and 138 kV transmission lines that pass directly through the property. This unique geographic advantage completely eliminates the need for new transmission corridor development, right-of-way acquisition, or complex permitting processes, leading to significant project acceleration. (Ref: ERCOT 2023 Planning Maps, Oncor Bosque-Elm Mott project filings)
By leveraging the immediate presence of existing Oncor and ERCOT transmission infrastructure, L2D2 can achieve direct interconnection. This eliminates all new transmission line construction costs and schedule risks, representing a major cost saving and timeline advantage compared to sites requiring new infrastructure development in congested nodes like Dallas-Fort Worth or Austin.
The existing on-site transmission lines are supported by stable soil conditions in the Elm Mott area, and flood plain analysis indicates minimal exposure to 100-year flood events, further reducing long-term operational risk for the transmission interconnection without the need for new infrastructure development. (Ref: Local Geological Surveys, FEMA Flood Plain Maps)
The **Bosque Switch** stands apart from other ERCOT transmission nodes through its unique combination of architectural attributes, operational capabilities, and strategic positioning. All primary interconnections at L2D2 utilize 345 kV; 138 kV serves as redundancy and operational flexibility.
This infrastructure convergence, coupled with the **direct presence of existing 345 kV and 138 kV transmission lines directly traversing the L2D2 site**, creates an unmatched foundation for hyperscale data center development at L2D2 in Elm Mott, Texas, setting it apart from more congested nodes like DFW or Austin where new interconnection can face extensive delays and infrastructure challenges. (Refer to ERCOT 2024 transmission planning report and Oncor Bosque-Elm Mott project filings for detailed validation).
Six independent 345 kV transmission corridors, complemented by additional 138 kV lines, already directly pass through the L2D2 site. This eliminates the need for new transmission line construction, right-of-way acquisition, or infrastructure upgrades, providing unmatched redundancy and routing flexibility for current needs and future expansion scenarios, without the typical queue times seen at other major ERCOT nodes. (Ref. ERCOT 2024 Planning Maps).
Direct connection to an active 807 MW combined-cycle power source delivers local voltage support, system stability, and spinning reserve capacity that enhances grid resilience, a critical advantage compared to nodes reliant solely on distant generation sources. (Ref. Oncor interconnection data, ERCOT 2024 transmission planning report).
North and South 345 kV and 138 kV bus configurations, featuring independent dual buses per voltage level with redundant topologies, ensure continuous operation during maintenance, outages, or contingency events—exceeding N-1 reliability standards and supports N-1 with enhanced redundancy approaching N-2 performance for critical loads, a significant differentiator for hyperscale operations. (Ref. Oncor Bosque Switch topology documents, ERCOT Transmission Studies).
Junction location between ERCOT's North and Central load zones provides stability anchor functionality and reactive power management for AI-driven, high-density compute applications, offering a unique geographical advantage over more peripheral nodes. (Ref. ERCOT 2024 Transmission Planning Report).
These architectural characteristics, critically enhanced by the pre-existing, direct access to both 345 kV and 138 kV transmission lines on-site, position Bosque as the optimal parent node for L2D2. This delivers unmatched scalability, resilience, and high-voltage efficiency for AI-driven, Tier IV-ready data center operations, requiring zero new transmission line construction to the site. This eliminates typical transmission development bottlenecks and offers significant MW availability, unlike often-congested major urban nodes. The combination of immediate transmission capacity, generation integration, and geographic factors creates a unique value proposition that cannot be replicated at alternative ERCOT nodes, with primary 345 kV and flexible 138 kV interconnection options available directly at the development site.
Phased development scaling from 150 MW to full 925 MW buildout via direct 345 kV interconnection to existing on-site lines, a level of immediate capacity rarely seen in new ERCOT interconnections. (Ref. Oncor Interconnection Agreement).
Multiple 345 kV transmission pathways, supported by 138 kV options, already present at the site, providing exceptional N-1 reliability and supports N-1 with enhanced redundancy approaching N-2 performance for critical loads and routing flexibility without new construction. This contrasts sharply with the limited and often oversubscribed circuits at many other ERCOT locations. (Ref. Oncor Bosque-Elm Mott project filings).
Ultra-efficient 345 kV transmission due to direct, on-site connection, minimizing losses from Bosque Switch to L2D2's existing infrastructure, yielding superior energy efficiency compared to sites requiring long-distance transmission. (Ref. ERCOT Load Flow Studies, ERCOT 2024 transmission planning report).
Thad Hill combined-cycle plant providing local voltage support and stability, a strategic asset for grid stability that mitigates reliance on distant, potentially unstable generation. (Ref. ERCOT Resource List, ERCOT 2024 transmission planning report).
For power system planners and infrastructure investors evaluating Central Texas opportunities, the Bosque-L2D2 interconnection represents a best-in-class infrastructure investment with clearly defined technical pathways, negligible project risk related to transmission line construction or right-of-way acquisition (a common risk factor at other ERCOT locations), and exceptional long-term operational performance. The convergence of existing on-site transmission (with primary 345 kV and flexible 138 kV options), generation, and geographic factors establishes this corridor as foundational infrastructure for Texas's next wave of hyperscale computing development. (Ref. ERCOT 2024 transmission planning report).
The unparalleled advantage of the L2D2 site lies in its direct access to existing transmission infrastructure. Both 345 kV and 138 kV voltage levels already pass directly through the property, a claim substantiated by the following technical references. This pre-existing infrastructure eliminates the need for any new transmission line construction, right-of-way acquisition, or costly upgrades, significantly streamlining project timelines and reducing complexity for direct connection to existing on-site infrastructure. This unique positioning is a critical factor for expediting development compared to other Texas nodes, which often face significant queue times and extensive new infrastructure requirements.
All technical claims regarding L2D2's direct access to existing 345 kV and 138 kV transmission lines, and the subsequent advantages, are verified against these primary sources. The pre-existing on-site transmission infrastructure significantly simplifies the engineering studies required for final project validation, bypassing common hurdles faced by other large load interconnection projects in regions like DFW or Austin.
Disclaimer: It is critical to ensure current data verification and professional engineering review for any final project decisions.
Why the Bosque Switch is Unique — and Its Strategic Role for L2D2