Solar developers rarely lack prospective sites. The harder problem is deciding which sites deserve scarce capital and engineering attention. Stronger pre-FEED screening can expose material weaknesses before interconnection, land and technical commitments deepen, improving the rate at which teams make defensible advance, hold or reject decisions.

Key takeaways

• Queue position is not project quality. At the end of 2025, US queues contained approximately 8,200 active projects representing 2,061 GW. Of the capacity submitted from 2000 through 2020, only 13% had reached commercial operation, while 75% had withdrawn, according to Berkeley Lab.
• Early commitments can be substantial. Under PJM’s May 2026 Manual 14H, a 100 MW request requires a $250,000 study deposit and $400,000 Readiness Deposit No. 1 at application, creating a combined $650,000 commitment before interconnection feasibility is established.
• Earlier rejection can prevent avoidable costs and exposure. For that 100 MW PJM example, stopping before application avoids posting $650,000, including a $25,000 non-refundable study-deposit portion, and prevents exposure to actual study costs and later readiness requirements.
• Portfolio velocity comes from decision quality. Standardized solar pre-FEED screening helps developers reject, hold or advance projects before substantial commitments are made, directing capital and specialist capacity toward opportunities supported by stronger evidence.

Portfolio velocity is the rate of defensible decisions

Renewable developers often control more sites than their teams or balance sheets can advance. The constraint is not report speed. It is deciding which project deserves the next dollar and hour of specialist attention.

That rate is portfolio velocity: the flow of evidence-supported advance, hold or reject decisions across a development portfolio. It does not mean moving every project forward faster. An early rejection can create more value than accelerating a weak project into a costly study process.

Solar pre-FEED feasibility is structured technical and commercial screening performed before front-end engineering design, or FEED, and before other detailed diligence. It tests whether a project concept has enough initial credibility to justify the next development gate while recording the uncertainties that remain unresolved.

Interconnection queues show scale, delay and attrition

An interconnection queue is the formal pipeline of projects seeking permission to connect to a transmission system. It is not a list of projects certain to be built.

Lawrence Berkeley National Laboratory’s Queued Up: 2026 Edition, covering data through the end of 2025, identified roughly 8,200 active projects representing 1,312 GW of generation and 749 GW of storage. Within that total, 549 GW had a draft or executed interconnection agreement but had not reached commercial operation.

The historical outcomes are more important than the headline volume. Of the generation capacity that submitted interconnection requests from 2000 through 2020, 13% had reached commercial operation by the end of 2025, while 75% had withdrawn. For projects completed in 2025, the median time from interconnection request to commercial operation exceeded five years.

A 2025 peer-reviewed Joule study, using data through 2023 from seven US ISO/RTO regions and 44 utilities, found that more than 80% of interconnection requests ultimately withdrew and that interconnection costs had more than doubled over the preceding decade. Assigned costs averaged 8% of capital expenditure for completed solar projects. For withdrawn solar projects, they would have represented about 30% of project cost if built. The authors do not present that 30% as money necessarily spent or lost.

Queue attrition does not prove that pre-FEED screening would have prevented each withdrawal. Network-upgrade allocations, restudies and commercial changes may emerge only after queue entry. The defensible case is narrower: screening can stop projects with detectable site, configuration or economic weaknesses from progressing unnecessarily.

Early development gates commit more than study fees

The phrase “capital tied up” requires precision. A non-refundable fee is an expense. A study deposit funds interconnection study costs and is reconciled against work performed. Readiness security may be cash, a letter of credit or another permitted instrument, with some becoming at risk on withdrawal. Land, consultants and staff time are separate categories.

FERC’s Order No. 2023 framework illustrates why land and financial readiness now matter earlier. Its pro forma requirements call for evidence of 90% site control when an interconnection request is submitted and 100% by execution of the facilities-study agreement, subject to limited exceptions and approved transmission-provider variations.

Current PJM requirements provide a concrete market example. For its 2026 Cycle 01, PJM’s application guidance requires an Applications and Studies Agreement, study deposit, Readiness Deposit No. 1, site control and specified technical data at entry.

For a request whose applicable project output and requested rights are both 100 MW, the study deposit is $250,000 and Readiness Deposit No. 1 is $4,000 per MW, or $400,000. The resulting $650,000 combines study funding and readiness support. It is not an automatic $650,000 expense or loss.

Ten percent of the PJM study deposit is non-refundable. The remaining 90% is refundable after actual costs are reconciled, and the developer remains responsible if study costs exceed the deposit. PJM’s Manual 14H, Revision 04, effective May 20, 2026, also shows that readiness deposits become progressively at risk at later decision points and remain separate from final-agreement security.

California uses a different structure. Under CAISO’s Appendix KK Resource Interconnection Standards dated June 25, 2025, a 100 MW request requires a $5,000 non-refundable application fee, a $150,000 refundable study deposit and a commercial-readiness deposit equal to twice the study deposit, or $300,000. The $455,000 total therefore combines an expense, study funding subject to cost reconciliation and readiness security that can be provided through permitted financial instruments. Refunds following withdrawal depend on incurred study costs and any applicable withdrawal penalty.

These PJM and CAISO examples are not parts of one universal sequence. They apply to different markets, tariffs and application processes. Interconnection is an early material gate, but not necessarily the first expenditure. Developers may incur site-control, legal, environmental, consulting and preliminary engineering costs before entering a queue.

There is no reliable public North American benchmark for the total land, consulting and internal cost attached to an average withdrawn solar project. A universal “cost per failed site” would therefore be artificial. What can be established is that application-stage commitments can be material before grid feasibility, network upgrades and other major uncertainties are resolved.

Actual forfeitures also occur. In September 2025, CAISO distributed approximately $18.6 million in non-refundable financial-security and study-deposit amounts associated with projects withdrawn through June 30, 2025. That aggregate relates to projects governed by legacy Appendix DD. It is not an Appendix KK entry cost, a typical loss per project or evidence that every withdrawal was preventable.

What pre-FEED screening should establish

A useful pre-FEED screen should answer four questions before a project crosses a deeper commitment gate:

• Is the site physically plausible? This includes usable area, terrain and slope, access and identifiable environmental or land constraints.
• Is the proposed configuration credible? Equipment, capacity and design assumptions should form a technically coherent initial concept.
• Do preliminary energy and economic results clear the developer’s screening thresholds? The assumptions and data limitations behind those results must remain visible.
• What remains unknown? Grid capacity, deliverability, network upgrades, permitting outcomes and field conditions should be identified as unresolved rather than converted into false precision.

The US Department of Energy’s i2X Transmission Interconnection Roadmap identifies better data access and transparency as important to project screening and siting. That information can improve pre-queue decisions, but it does not replace the transmission provider’s system models and studies.

The appropriate pre-FEED output is therefore a documented gate recommendation: advance, hold pending specified evidence, or reject. The value lies in making that recommendation early enough to influence the next commitment.

Stronger screening changes portfolio allocation

Renewable project portfolio prioritization improves when every site has a common analytical baseline. Standardized screening exposes inconsistent assumptions, material constraints and evidence gaps hidden by different spreadsheets or decision standards.

This changes portfolio allocation. Weak candidates can be stopped or deferred before additional fees, security and consultant costs arise. Engineers and commercial staff can concentrate on the projects whose uncertainties are worth resolving.

The result is not simply faster analysis. It is a higher rate of decisions that development management and an investment committee can review, challenge and defend.

How SolarAIDE supports solar pre-FEED decisions

SolarAIDE™ is ABEN HUB’s human-in-the-loop AI decision engine for utility-scale, community solar and large commercial and industrial (C&I) solar pre-FEED screening. BESS compatibility is currently in development. Starting with a defined site polygon and configurable project assumptions, SolarAIDE completes its automated analysis in minutes and produces a standardized screening pack covering site and terrain conditions, environmental constraints, grid proximity, preliminary energy performance and early project economics.

The platform is designed to support professional judgment, not replace it. SolarAIDE presents the evidence, assumptions and identified constraints, while the origination team retains responsibility for the final advance, hold or reject decision. Real-world use during SolarAIDE’s early-access program has verified that the platform can apply this workflow across different project sites and produce usable pre-FEED outputs.

In observed early-access workflows, users have been able to review the outputs, challenge key assumptions and finalize an initial screening decision within approximately two hours. Comparable screening using conventional research, analysis and reporting methods can require more than 40 hours of work. For these workflows, SolarAIDE enabled teams to screen and prioritize candidate sites more than 20 times as fast while preserving human oversight of the final decision.

At the portfolio level, this standardization matters as much as the analysis of any individual site. Teams can compare opportunities using common inputs, criteria and outputs rather than reconciling unrelated reports and spreadsheets. Assumptions become easier to challenge, material constraints are surfaced consistently, and the rationale for advancing, holding or rejecting a site is easier to document. This allows origination teams to evaluate more opportunities while directing development capital and specialist attention toward the projects supported by stronger early evidence.

What SolarAIDE does not replace

SolarAIDE does not determine available grid capacity or guarantee interconnection. It does show grid proximity, which provides useful context, but is not evidence of available capacity, deliverability or an acceptable interconnection cost.

This distinction matters because interconnection is a major and highly selective development gate. Lawrence Berkeley National Laboratory’s Queued Up: 2026 Edition found that, of the generation capacity entering US interconnection queues from 2000 through 2020, only 13% had reached commercial operation by the end of 2025, while 75% had withdrawn. In other words, approximately three-quarters of the proposed capacity did not progress to operation.

SolarAIDE sits upstream of this major decision gate. It does not replace an ISO/RTO, utility or transmission-provider interconnection study; binding site-control and legal due diligence; field investigations; permitting and environmental approvals; geotechnical or survey work; detailed engineering or FEED; a bankable energy-yield assessment; independent engineering review; or investment-committee judgment.

Its role is to help origination teams determine which projects have enough supporting evidence to justify incurring those later, more substantial costs. By quickly identifying material site, configuration and economic constraints, SolarAIDE helps teams reject or hold weaker candidates earlier and move stronger projects into interconnection and detailed development with a clearer basis for doing so.

Portfolio velocity follows better development gates

Developers can originate prospective capacity faster than grids, development teams and balance sheets can convert it into operating assets. Portfolio value therefore depends on stopping weak opportunities before their claims on capital and specialist capacity grow.

Solar pre-FEED feasibility creates an evidence standard for that earlier decision. SolarAIDE applies that standard consistently, giving development teams a practical way to decide which sites should advance, which require more evidence and which should stop.

FAQ

What is solar pre-FEED feasibility?

It is structured technical and commercial screening performed before FEED and other detailed diligence. It tests whether a solar concept is credible enough to justify the next development gate and identifies the uncertainties requiring formal investigation. In conventional development workflows, this process often requires separate contributions from origination, siting, engineering, environmental, interconnection and commercial teams.

How much can a 100 MW project commit at interconnection entry?

It depends on the market and year. PJM’s 2026 Cycle 01 requirements imply $650,000 in study funding and readiness support. CAISO’s June 2025 Appendix KK implies $455,000 in application fee, study deposit and readiness security. Neither amount is automatically spent or lost.

Does proximity to a substation establish interconnection feasibility?

No. Proximity is contextual evidence. Available capacity, deliverability, network upgrades, cost allocation and schedule must be established through the applicable transmission-provider process and engineering studies.

What has SolarAIDE’s early access program verified?

The early access program has verified that SolarAIDE can apply its pre-FEED workflow to real project sites, produce standardized screening outputs, surface material early-stage constraints and support project-gate decisions.

References

• Queued Up: 2026 Edition: Characteristics of Power Plants Seeking Transmission Interconnection as of the End of 2025, Joseph Rand et al., Lawrence Berkeley National Laboratory, May 2026. Supports current US queue volumes, historical commercial-operation and withdrawal outcomes, and request-to-operation timing.
• Grid connection barriers to renewable energy deployment in the United States, Will Gorman et al., Joule, February 19, 2025. Supports request-withdrawal findings and the scale of assigned interconnection costs for completed and withdrawn projects.
• Explainer on the Interconnection Final Rule, Federal Energy Regulatory Commission, Order No. 2023 effective November 6, 2023, with Order No. 2023-A issued March 21, 2024. Supports cluster-study, commercial-readiness, withdrawal-penalty and site-control requirements.
• Transmission Interconnection Roadmap, US Department of Energy, April 2024. Supports the role of better data access and transparency in project screening and siting.
• Cycle 01 Application Requirements and NextGen Process, PJM Interconnection, January 26, 2026. Supports the Cycle 01 application requirements, study-deposit brackets and Readiness Deposit No. 1.
• PJM Manual 14H: New Service Requests Cycle Process, Revision 04, PJM Interconnection, effective May 20, 2026. Supports study-deposit reconciliation, readiness-deposit timing, withdrawal exposure and separation from final security.
• CAISO Tariff, California Independent System Operator, accessed July 23, 2026. Confirms that CAISO maintains approved and pending tariff language separately.
• CAISO Tariff Appendix KK: Resource Interconnection Standards, California Independent System Operator, document dated June 25, 2025. Supports the application fee, study-deposit schedule, commercial-readiness deposit and withdrawal reconciliation.
• Generator Interconnections 2025 Non-Refundable Funds Distribution, California Independent System Operator, September 5, 2025. Supports the aggregate amount distributed from non-refundable security and study-deposit funds for qualifying withdrawn Appendix DD projects.