Wet Stamp Meaning & Solar Stamping Guide
- Sarah Lozanova
- a few seconds ago
- 13 min read
Table of Contents
-- Why Solar Panel Stamping Is Critical for Projects
Before starting any solar panel installation, battery storage upgrade, or PV system expansion, you’ll need approval from your Authority Having Jurisdiction (AHJ). Solar permitting requirements vary widely across the U.S., depending on state, city, county, and utility company rules.
In many cases, you’ll need a wet stamp, also called a PE stamp, to move forward. A PE stamp (Professional Engineer stamp) means a licensed engineer has reviewed and approved your project’s solar design, confirming it meets all safety codes and local regulations. Without the right solar panel stamping, projects can be delayed, rejected, or face costly redesigns.
Some municipalities require an electrical permit for solar panel installation, while others mandate a building permit. Local ordinances may modify state building codes due to climate, topography, or geological factors. As a result, solar engineering requirements can differ even between neighboring counties.
Most solar permitting rules are based on the National Electrical Code (NEC) and building codes, but many AHJs demand PE-stamped drawings or additional engineering approvals. This typically requires an electrical, structural, or civil engineer to review project plans and apply their seal, confirming compliance with all regulations. Some jurisdictions accept a letter from a state-licensed engineer instead of a PE stamp, stating that the structure can handle the additional solar system load.
Before submitting your permit application, check whether your project requires PE stamping, wet seal stamps, or signed engineering letters. Being prepared upfront helps avoid delays and keeps your solar installation on schedule. GreenLancer has over a decade of experience providing solar engineering, PE stamping, and permitting services nationwide to solar contractors.
What Is a PE Stamp? Understanding Solar Engineering Wet Stamps
In industries like engineering, architecture, and surveying, official documents often require verification through a PE stamp. In solar and EV charging projects, a PE stamp or wet stamp means that a licensed engineer has certified the design as compliant with all applicable codes and professional standards. This approval is crucial for permitting and liability purposes.
A PE stamp, sometimes mandatory, sometimes optional, serves as an engineer’s registration seal, confirming they take responsibility for the design’s structural and electrical integrity. This can be especially important in areas with strict permitting requirements.
Wet Stamp vs Digital PE Stamp: Key Differences for Solar Stamping
A wet stamp is physically applied with ink or embossing on paper plans, along with an ink signature and date.
It includes key details like the engineer’s name, license number, and possibly their affiliated organization.
Many AHJs now accept digital PE stamps, which expedite approvals and reduce paperwork.
Only a certified professional engineer can issue an engineering wet stamp. Earning this certification requires a four-year engineering degree, work experience under a licensed PE, and passing two rigorous exams. Since each state regulates PE qualifications, requirements may vary, making it essential to verify local regulations before submitting stamped drawings.
GreenLancer offers professional solar engineering services, including engineering reviews and PE-stamped drawings, to help streamline the permitting process. With access to licensed engineers across the U.S., we ensure your project meets all AHJ requirements, reducing delays and keeping installations on schedule.
PE Stamp Meaning vs Wet Stamp Meaning: What Solar Installers Need to Know
A PE stamp and a wet stamp are closely related but not identical. While both certify documents, a PE stamp specifically signifies approval from a licensed Professional Engineer. It confirms that an engineer has reviewed and validated the design, ensuring compliance with safety codes and regulatory standards.
In contrast, the wet stamp meaning refers to the physical process of stamping documents, which isn’t exclusive to engineering. A wet stamp is a physical inked or embossed imprint applied by licensed professionals across industries like architecture, surveying, and notarization. Although a PE stamp is a type of wet stamp, not all wet stamps indicate engineering approval.
Both stamps play a crucial role in verifying the legitimacy of professional work. However, a PE stamp uniquely certifies that a licensed engineer is responsible for the design’s integrity, making it essential for many solar, EV charging, and energy storage permitting processes.
Why PE Stamps & Wet Stamps Matter for Solar Panel Stamping and Permitting
Securing the correct engineering wet stamp or PE stamp is a crucial step in any solar, EV charging, or energy storage project. A PE stamp means a certified engineer has reviewed the system design, ensuring compliance with safety codes and performance standards. Without this approval, your project could face permitting delays or fail to meet regulatory requirements.
Engineers providing a PE stamp go through rigorous calculations to verify system viability, evaluating structural integrity, electrical safety, and code adherence. If a project lacks the necessary wet stamp, it could lead to major safety risks, operational failures, or even rejection by the Authority Having Jurisdiction. Ensuring proper certification from the start helps prevent costly rework and keeps your installation on track.
Solar Panel Stamping: How to Get a PE Stamp or Wet Stamp for Permitting
Some AHJs require a physical wet stamp—either inked or embossed—on paper drawings, while others accept digitally sealed engineer-approved documents. If digital PE stamps are permitted, they can streamline the process, saving time, money, and resources compared to traditional wet stamps.
Steps to Obtain a PE Stamp:
Determine AHJ Requirements
Check whether your jurisdiction requires a wet stamp or accepts digital PE stamps.
Verify if the project needs an electrical, structural, or civil engineering review.
Work with a Licensed Professional Engineer
A PE must review and approve project drawings to issue the required stamp.
Many solar, battery storage, and EV charging professionals use specialized engineering services.
Plan for Engineering Costs
Pricing varies based on the number of drawings and project complexity.
Factor in additional costs if revisions or extra certifications are needed.
GreenLancer provides comprehensive solar engineering services, including permit plan reviews and PE-stamped drawings to meet AHJ requirements. Whether you need electrical, structural, or civil analysis, GreenLancer connects you with licensed engineers who can provide digital stamps or wet stamps for solar, EV charging, and generator projects, ensuring compliance and a smooth permitting process.
Types of PE Stamps for Solar Stamping & EV Charger Installations
PE stamps are critical in certifying that installations meet regulatory, safety, and technical standards for solar and EV charging station projects. Here’s a deeper look at the various types of engineering stamps commonly required:
Electrical Engineering Wet Stamps
For solar and EV charging projects, a PE stamp from an electrical engineer is essential to ensure that your system meets all electrical codes and safety standards. Whether it's a new solar installation or an upgrade to existing electrical systems, an electrical engineering wet stamp guarantees that your design has been reviewed and approved by a qualified professional.
What an Electrical PE Stamp Covers
System Design: The electrical engineer checks the design for proper circuit sizing, load calculations, and compliance with the National Electrical Code.
Safety Compliance: The stamp ensures that the system is designed to prevent electrical hazards, including overcurrent protection, grounding, and arc fault protection.
Energy Flow Analysis: The engineer will verify that energy flow is optimized, ensuring efficiency and that the system can handle peak loads without issues.
When You Need an Electrical PE Stamp
New Installations: If your project involves new electrical components, you’ll need an electrical PE stamp to confirm the system’s design complies with local regulations.
Upgrades: For systems that require electrical upgrades (such as increased panel capacity or battery storage), an electrical PE stamp ensures that the new design integrates seamlessly and safely.
Structural Engineering Stamps
A structural engineering stamp is crucial when installing solar panels or EV infrastructure, as it affects the structural integrity of a building or requires ground mounting. Engineers must evaluate the ability of the roof or foundation to support the added weight of solar panels, considering factors such as:
Roof Framing and Load Calculations: Engineers assess how the solar panels’ weight interacts with the building’s existing structure. This includes calculations for vertical loads, such as the panels' weight, and dynamic loads, like wind or snow.
Seismic and Wind Loads: Structural engineers must ensure that the mounting system can withstand these forces in regions prone to earthquakes or high winds, such as coastal or hurricane-prone areas. They may use wind load calculations and seismic reinforcement methods to certify that the installation complies with International Building Code (IBC) standards and local amendments.
Structural engineers must ensure the foundations can support ground-mounted PV systems while accounting for soil composition and maximum wind speeds. In such cases, wet stamps or PE-stamped drawings provide AHJs with certified evidence of the project’s safety.
Structural engineers assess how the solar panels' weight interacts with the building's existing structure, including vertical, wind, and snow loads. This level of structural scrutiny is becoming standard for many residential projects beyond solar; for example, engineering is often required during basement remodels to verify that the existing foundation and floor framing can support new living space layouts or structural alterations.
Civil Engineering Wet Stamps
While less common in residential solar projects, civil engineering stamps are often required for large-scale solar farms or public EV charging stations. Civil engineers focus on the infrastructure surrounding the installation, which can include:
Site Grading and Drainage: Civil engineers may need to ensure proper site preparation, addressing issues like erosion control, drainage systems, and land leveling for solar farms.
Roads, Parking, and Utilities: For EV charging stations, especially those in public or commercial spaces, civil engineers are responsible for designing access roads, parking lot layouts, and utility connections that integrate seamlessly with existing infrastructure. They may also ensure that the installation meets ADA (Americans with Disabilities Act) compliance for accessibility.
Civil engineers may provide wet stamps or PE stamps to verify that the site development complies with local building codes, environmental regulations, and infrastructure standards.
PE Stamp Licensing Requirements Explained for Solar, EV, & Energy Projects
Licensing requirements for obtaining a PE (Professional Engineer) stamp vary by state and jurisdiction. Still, there are some common requirements that most engineers must meet to be eligible to use a PE stamp. Here are some general guidelines regarding PE licensing requirements:
Education: Typically, individuals seeking a PE license must have a bachelor's degree in engineering from an ABET-accredited program or equivalent. Some states may require additional education, such as a master's degree or specific coursework.
Experience: Most states require a certain amount of work experience under the supervision of a licensed Professional Engineer, which can range from 4 to 8 years, depending on the state and the individual's education level.
Examination: To obtain a PE license, engineers usually must pass the Fundamentals of Engineering (FE) and Principles and Practice of Engineering (PE) exams. The PE exam is specific to the engineer's discipline (e.g., civil engineering, mechanical engineering).
Ethics: Engineers are required to adhere to a code of ethics and conduct themselves in a professional and responsible manner.
Licensed professional engineers are typically required to be licensed in the state where they offer engineering services. This ensures that they comply with local regulations, codes, and standards. However, some states have reciprocity agreements that allow engineers licensed in one state to obtain a license in another state without having to take additional exams, provided they meet certain requirements.
Engineers should know the licensing requirements specific to the state or jurisdiction in which they intend to practice. They should contact the state licensing board or regulatory agency for engineering to get detailed information on the specific requirements and processes for obtaining a PE license and using a PE stamp in that state.
When a PE Stamp or Wet Seal Stamp is Required for Solar Panel Permitting
PE stamps are often necessary for solar permitting in the following situations:
Structural Modifications: If the solar installation involves structural modifications to a building or structure, such as roof reinforcement or structural supports for ground-mounted systems, a structural engineering stamp may be required to certify the structural design and ensure compliance with building codes.
Electrical Design: For grid-connected solar PV systems, an electrical engineering stamp may be required to certify the electrical design, including wiring diagrams, equipment specifications, and safety considerations, to ensure compliance with electrical codes and regulations.
Professional Oversight: In some jurisdictions, solar installations may require professional oversight by a licensed engineer to ensure compliance with engineering standards and best practices, particularly for large-scale solar farms or complex projects.
Regulatory Requirements: Certain regulatory agencies or local building authorities may require PE stamps as part of the permitting process to verify the safety, integrity, and compliance of the solar installation with applicable codes and regulations.
Consult with local building authorities, engineering professionals, and regulatory agencies to determine whether a PE stamp is required for your specific solar permitting needs and to ensure compliance with relevant regulations and standards.
Solar Panel Stamping & PE Stamps: Why They’re Critical for Solar and EV Projects
If engineering stamps are needed for a project, they must be provided to obtain project permits and prevent delays. Because most solar energy, battery storage, and EV professionals don’t typically have these capabilities in-house, partnering with an engineering firm that offers electrical, structural, and civil engineering seals, reviews, and letters is critical.
GreenLancer has a network of certified engineers with expertise in every AHJ in the country and beyond. Sign up for free today to find your next solar or EV charging engineering partner and simplify your design and engineering process.
FAQ: Solar Wet Stamps, PE Seals, and Permit Plan Sets
What is a wet stamp?
A wet stamp is the traditional, physical method of sealing engineering documents, typically an inked stamp or embossing seal, paired with an original handwritten signature and date. Some jurisdictions use “wet stamped” as shorthand for “originally signed and sealed,” even if they later accept scanned copies. Requirements can vary by jurisdiction and by the permitting office’s submittal workflow.
What is a structural engineer stamp for solar, and when do you need it?
A structural engineer stamp (often called a PE stamp when the engineer is a licensed Professional Engineer) indicates the structural review and calculations were performed under that engineer’s responsible charge for the PV attachment method and loading assumptions (dead, live, wind, snow, etc.). You typically need it when:
The permit office requires stamped calcs/letters for rooftop PV attachments
Your racking/attachment doesn’t match prescriptive tables, or the building department wants project-specific verification
The building is higher-risk (older framing, unusual spans, heavy snow/wind exposure, nonstandard roof construction). This is the backbone behind many “solar structural certification” requests from plan reviewers.
What does a PE stamp for solar plans actually mean?
A PE stamp (a licensed professional engineer stamp) is the engineer’s seal plus signature/date on the applicable documents. In plain terms: it identifies who is legally responsible for that engineering work and confirms the documents were prepared by (or under the responsible charge of) the licensee.
Are solar engineering stamps the same as “wet stamps”?
Often, people use the terms interchangeably, but they’re not always the same thing:
Solar engineering stamps refer to the sealed/signed engineering deliverable (structural, electrical, or both).
Wet stamp refers to the method (physical ink/emboss + original handwritten signature). Many jurisdictions now accept electronic sealing, but some AHJs still request “wet signed” originals for certain workflows.
What is a wet stamp in engineering, and why do AHJs still ask for it?
In engineering, “wet stamp” usually implies a physical seal plus a pen signature/date (not just a stamp image dropped onto a PDF). Building departments may still ask for wet stamps because:
Their permitting rules were written around paper plan sets
They want clear accountability and tamper-resistance
Their intake process hasn’t fully transitioned to digital verification. If you run into this, it’s worth confirming whether they mean “wet signed originals” or simply “sealed/signed documents.”
What is an electrical engineer stamp for solar used for?
An electrical engineer stamp for solar is typically used when a code office (or utility/interconnection package) requires an engineered review of electrical design elements such as one-line diagrams, conductor/OC protection sizing, service equipment constraints, or other nonstandard conditions. This may also be described as a solar electrical engineering seal on the electrical sheets of the permit set.
What are common solar PE stamp requirements?
Solar PE stamp requirements depend on state rules and local permitting standards, but common triggers include:
Structural verification required for roof attachments (often snow/wind driven)
Non-prescriptive or unusual mounting conditions
Larger/more complex projects (or projects outside standard residential templates)
Jurisdiction policies that require sealed drawings/calculations for certain PV scopes. Your AHJ (and sometimes the utility) sets the submittal expectation, and the PE seal is the compliance mechanism.
Wet stamp meaning: does it mean the seal has to be embossed?
Not necessarily. In many contexts, “wet stamp” just means a physically applied seal (ink stamp or emboss) and an original signature/date. Some jurisdictions explicitly allow either physical or electronic seals, as long as the seal/signature/date requirements are met.
What is solar panel stamping? Is it the same as plan stamping?
In permitting language, solar panel stamping usually refers to stamping the drawings and calculations for the solar project (not stamping the panels themselves). It’s essentially the same concept as stamping the solar plan set sheets, details, calculations, or an engineer letter that supports the permit review.
What do PE stamping services usually deliver in a solar PV permit package?
A solid solar PV permit package with stamping typically includes:
Site/roof plan + layout (module count, setbacks where required, attachment callouts)
Structural notes and (when needed) calcs or an engineer letter
Electrical one-line, equipment specs, placards/labels schedule
The sealed/signed pages (the “engineer stamp drawings”) applicable to the scope. This is designed to reduce plan check comments and speed AHJ intake.
How does digital seal vs wet stamp (2025) work—are electronic seals valid?
What’s the difference between an image seal and a real digital signature?
A pasted image of a seal on a PDF may not meet a board’s requirements if the jurisdiction expects a verifiable, tamper-evident digital signature. Many engineering boards emphasize controls that invalidate the signature if the document changes—this is a key distinction for compliance and for avoiding rejected submittals.
What does structural analysis for solar typically cover?
Structural analysis for rooftop PV typically checks:
Existing framing assumptions (rafters/trusses spacing, spans, sheathing)
Attachment method and load path into the structure
Wind uplift and snow load considerations for the specific jurisdiction
Concentrated loads at attachment points and allowable capacities. This is what plan reviewers are looking for when they request “solar structural certification.”
What is the cost of a solar PE stamp?
The cost of solar PE stamp services varies a lot based on scope (structural vs electrical vs both), project complexity, jurisdiction, and turnaround time. In the market, you’ll commonly see residential stamping priced in the low hundreds, with commercial or complex projects often higher. If you’re comparing quotes, make sure you’re comparing the same deliverables (stamped calcs/letter vs stamped full plan set sheets).
What are practical solar stamping guidelines to avoid AHJ rejections?
A few field-tested guidelines that help with AHJ permit approval engineering reviews:
Match the stamp scope to the sheets: structural stamp on structural support docs, electrical stamp on electrical design docs (don’t “over-stamp” unrelated pages).
Ensure seal + signature + date conventions align with that state board’s rules and the AHJ’s submission format.
Use consistent project identifiers (address, system size, revision/date) so plan check can track versions cleanly.
If the AHJ is picky about “wet stamps,” ask whether a compliant electronic seal/digital signature is accepted for 2025-style online intake.