Reading the Map Before It's Drawn: How to Evaluate Sites Against Proposed Transmission Projects
- Craig Kaiser
- 1 minute ago
- 6 min read
Most site selection workflows are built around infrastructure that already exists: substations with known interconnection queues, transmission lines with published available transfer capacity, distribution networks with documented hosting capacity. Proposed projects don't offer that same certainty. They offer something else: a window to secure site control before capacity becomes visible to every other developer scanning the same region. To win in this market, developers need to read the map before it’s drawn and identify where the grid will be years before the steel hits the ground.
What are Proposed Transmission Projects, and Why are They Important?
Proposed transmission lines are electric transmission projects that have been announced, planned, or are under development but have not yet been constructed or energized. They are intended to expand or strengthen the electric grid by increasing transmission capacity, improving reliability, connecting new generation resources, or relieving congestion.Â
Proposed transmission projects span a wide range of certainty. Some are fully permitted and under construction, with a firm in-service date and committed financing. Others are early-stage proposals still working through regional planning studies, years away from breaking ground, with a real chance of being delayed, rerouted, or cancelled entirely. Before a proposed line factors into a site selection decision, the first question is where it sits on that spectrum, not just whether it appears on a map.
For data center, BESS, and renewable energy developers, tracking projects while they are still in the proposed phase (rather than waiting until they are built) offers a massive strategic edge:
First-Mover Advantage on Capacity: Existing transmission lines are often maxed out, leading to multi-year wait times in interconnection queues. Aligning a project with a planned line allows developers to secure a spot in a brand-new queue before capacity is spoken for.
Lower Land Costs: Buying or leasing land next to power (near an existing substation or active line) commands a steep premium. Securing site control along a planned but unbuilt corridor keeps land acquisition costs low.
Mitigating Curtailment Risk:Â For solar and wind developers, connecting to an overloaded grid means your power might be turned off (curtailed) during peak generation. Planned lines are specifically built to relieve this congestion, lowering operational risk.
By tracking detailed metrics of proposed projects - such as the project name, type, voltage capacity, and operating utility - developers can effectively predict where the energy markets will thrive five to ten years down the road. LandGate's Proposed Transmission Line data layer maps proposed projects across the U.S. with detailed attributes including voltage, owner, project type, and status, giving solar, BESS, and data center developers a single view to screen corridors against the criteria that matter most for their project type.
How to Leverage Planned Grid Infrastructure
Having access to forward-looking grid data is only half the battle; the real value lies in how you weaponize it against your competition. Because data centers, solar farms, and battery storage systems interact with the grid in fundamentally different ways, a proposed transmission line represents a unique strategic lever for each asset class.
Across all three, the value of planned transmission data comes down to the same thing: visibility into where capacity is headed, not just where it already exists. That visibility is what allows a developer to secure a site before a corridor's capacity becomes obvious, and contested, to everyone else evaluating the same map.
Data Centers: Securing Power in a Constrained Market
For data center developers, the primary constraint on growth is the enormous amount of power required to support next-generation AI clusters. Hyperscale facilities now routinely require hundreds of megawatts of continuous, highly reliable electricity. Rather than competing for limited capacity at existing substations with years-long interconnection queues, developers can use proposed transmission data to identify future high-voltage corridors where new grid capacity is already being built.
This allows developers to secure land while it's still relatively inexpensive, begin utility coordination early, and align development timelines with the completion of new transmission infrastructure. Just as importantly, it helps to avoid investing time and resources in markets where future power capacity won't be available in time to meet their project schedules.
Solar: Beating the Interconnection Queue and Curtailment
Solar developers often operate within narrow interconnection windows, where timing and queue position can determine whether a project moves forward quickly or remains delayed in studies for years. Proposed transmission data provides a forward-looking advantage by identifying emerging development corridors before they become congested, allowing developers to target areas where new grid capacity is being added or regional bottlenecks are being relieved.
By evaluating proposed line voltage and project type alongside existing hosting capacity and available transfer capability (ATC) data, solar developers can gain insights that current interconnection queues alone cannot provide. This enables them to secure site control early, optimize project design, minimize the risk of costly network upgrades, and submit interconnection requests as new injection capacity comes online - improving both project economics and development timelines.
BESS: Pinpointing Future Nodal Congestion and Arbitrage
Battery storage developers have greater siting flexibility than solar or data center developers because standalone storage doesn't need to be co-located with a specific generation resource. That flexibility makes proposed transmission data especially valuable, allowing BESS developers to select sites based on where future grid capacity and transmission infrastructure will be available rather than today's congestion patterns, which can change as the grid evolves.
Proposed transmission projects provide a roadmap of the future grid, helping BESS developers identify strategic locations - such as new substations, interconnection points, and corridors connecting renewable generation to major load centers - where storage will be well positioned to absorb excess energy, improve grid reliability, and capitalize on long-term energy arbitrage opportunities. In many cases, lower-voltage subtransmission projects can also offer attractive siting opportunities with less competition than major bulk transmission corridors.
Access Planned Transmission Line Data with LandGate
LandGate now includes maps of nationwide proposed transmission lines across the nation. This predictive mapping asset offers complete visual intelligence across the United States, displaying upcoming transmission projects well ahead of their construction phase. By identifying corridors where new transmission infrastructure is officially planned but not yet built, developers can secure low-cost site control along lines that are guaranteed to have open, unallocated capacity. This effectively bypasses the gridlock of over-congested existing routes.
Rather than providing simple lines on a map, LandGate provides comprehensive data for each planned project including voltage, owner, and project name.
Voltage
The voltage of a proposed transmission line is one of the clearest signals of what kind of load or generation it's designed to accommodate. High-voltage bulk transmission lines, typically 230kV and above, are more likely to support large interconnection requests, the kind a utility-scale solar project or a hyperscale data center campus would bring. Lower-voltage subtransmission projects often have a lower capacity ceiling but can still be a strong fit for distributed solar or BESS facilities that don't require bulk-scale headroom.
This matters across all three asset classes, but the threshold for "enough capacity" looks different depending on what you're building. A data center developer screening a planned line for a multi-hundred-megawatt campus is asking a very different capacity question than a BESS developer screening the same line for a 50-megawatt standalone storage facility, even though both are reading the same voltage data.
Owner
Who's developing the line affects both its likelihood of completion and how predictable its timeline is. Utility-owned projects tied to a regulatory rate case tend to move on more structured, if sometimes slower, timelines. Independent or merchant transmission developers can move faster but carry more financing and siting risk, since their projects aren't backstopped by the same regulatory cost recovery.
Project type adds another layer. A proposed line built specifically to relieve a known reliability constraint behaves differently than one built as a greenfield corridor designed to unlock new generation or load interconnection in a growth market. The latter is often the more interesting case for solar, BESS, and data center developers alike, since it usually signals that regional planners already expect new capacity demand in that corridor, which is exactly the kind of demand your project represents.
Project Type
Whether a proposed line is AC or DC is worth flagging separately, since it points to a different purpose and risk profile. AC lines make up the large majority of proposed transmission projects and are typically built to serve regional capacity needs, including the kind of localized load growth that solar, BESS, and data center interconnection requests usually tie into. HVDC lines are less common, generally longer in distance, and tend to be purpose-built to move large blocks of power between specific points, often from a remote generation hub to a distant load center. An HVDC project can still represent real opportunity, but it's typically less useful for general-purpose regional interconnection and more relevant for developers whose site happens to sit near one of its planned terminals.
Want to see how proposed transmission data fits into your site selection workflow? Book a demo with LandGate to explore the Proposed Transmission Line layer for your target markets.
