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What's An Engineering Stamp For Solar or EV Charging Projects?

Updated: Apr 25

wet stamp

Before installing a solar system, battery storage, or EV charger, it is critical to get the necessary permission from the Authority Having Jurisdiction (AHJ). However, solar and EV charging station permitting and interconnection requirements vary widely across the United States, depending on state, county, city or municipality, and utility company. Often, a wet stamp or professional engineer (PE) stamp is required to permit certain projects.

For example, some municipalities require an electrical permit to install solar panels, while others require a building permit. Likewise, some counties and cities may have local ordinances that amend state building codes due to climatic, topographic, or geologic factors. Therefore, solar permitting requirements vary across states and even counties within the same state.

Solar and EV permitting requirements are based partially on National Electrical Code (NEC) and building codes. However, some AHJs require professional engineer (PE)-stamped drawings during the permitting process.

This requires working with an electrical, structural, or civil engineer to review the project plans and provide their digital seal. It involves a third party with extensive engineering knowledge to check site plans and solar designs. However, cities might not require PE stamps for all projects. In some cases, a letter from a state-licensed engineer stating the building can handle the additional load of a solar system is required.

Before starting the solar permitting process, it’s essential to get organized and determine if PE-stamped PV drawings, an engineering review, or letters are required.

What Is A PE Stamp or Engineering Wet Stamp?

Many industries have standards that contractors need to follow. PE stamps are commonly used in fields such as engineering, architecture, notarization, and surveying, where official documents require verification and validation. A PE stamp means that a solar power installation, EV charger, or energy storage project has been designed to applicable codes and professional standards.

This means that a PE has offered their “registration seal” on the drawings, showing that it is an engineer-certified plan. It shifts liability because it shows that an engineer is responsible for the plan’s integrity. Sometimes, PE stamps are required, whereas other times, they are optional.

A wet stamp is applied via ink or embossing on paper plans and includes an ink signature and date. It often includes important identifying information, such as the professional's name, title, license number, and sometimes the organization or agency they are affiliated with. However, many AHJs allow digital engineering stamps. When possible, using digital stamps on drawings instead of wet stamps helps expedite the process, saving time, money, and paper.

A certified PE can provide an engineering wet stamp. Certification requires a 4-year degree, working under another PE, and passing two exams. Each state regulates the given PE qualifications.

solar engineering services

Is a PE Stamp And Wet Stamp The Same Thing?

Engineering wet stamps and PE stamps are often used interchangeably. While engineering wet stamps and PE stamps are similar in their purpose of certifying documents, a PE stamp specifically represents the certification and approval of a licensed Professional Engineer. The wet stamp, on the other hand, can be used by professionals in different fields for official validation.

A PE stamp is a personalized, legally recognized marking tool used by licensed engineers to approve and certify engineering drawings and plans. It signifies that a Professional Engineer has reviewed and taken responsibility for the engineering work being performed. The PE stamp is typically applied to documents such as structural plans, electrical schematics, or mechanical designs after the engineer has thoroughly examined and verified their accuracy and compliance with relevant codes and standards.

On the other hand, a wet stamp refers to the physical stamp or raised seal used by licensed professionals across various fields, including engineering. It can be used by engineers, architects, surveyors, and other professionals to validate and authenticate their work.

Why Are Wet Stamps Or PE Stamps Important?

Getting the right engineering wet stamp or PE stamp is vital to any project – and must be completed by a certified engineer. This critical step ensures that the system passes muster, fulfilling safety requirements and ensuring the system will run as expected. Engineers will walk through complex calculations to check and validate system viability. If a project does not receive the proper checks and official wet stamps, there could be major safety and use concerns for clients as their system comes online.

PE Stamps for Solar Energy & EV Charging Station Projects

Various AHJs have different requirements for engineer-stamped drawings. Often, the requirements vary depending on the climate or if the area is prone to natural disasters. For example, wind loads might be a top concern in some climates due to hurricanes. In other locations, seismic activity might be a big consideration.

Let’s look at the different types of wet stamps you may encounter when permitting solar or EV charging station projects.

Electrical Engineering Stamps

When an electrical engineer approves electrical designs involving solar modules, they will look at wire sizing, interconnection method, and other electrical aspects of a project. Therefore, it is critical that the electrical infrastructure can handle the load from solar projects in order to be certified.

Structural Engineering Stamps

There are various forces at play on homes, buildings, and ground mounts, including vertical loads, horizontal loads, and longitudinal loads. The structural analysis examines the forces of these loads on structures and other elements, including snow, seismic, dead, imposed, and wind loads. This process also entails looking at the roofing material, the type of roof framing, the weight of the PV modules, site-specific structural calculations, and the structural design of a racking system.

Obtaining a structural wet stamp requires a structural engineer to review the drawings, taking into account these various loads and the code and safety requirements of the AHJ. For example, it might include reviewing wind load calculations and solar panel racking system details. Pole mounts might require specific information about the foundation, considering the soil composition and maximum wind loads.

Civil Engineering Stamps

Civil engineers work on infrastructure relating to roads, bridges, airports, and other projects. Although civil engineer-approved drawings are somewhat rare for residential to smaller-scale solar projects, they are more common with larger commercial and utility-scale solar installations. Likewise, EV chargers in public parking lots may require civil engineer-stamped drawings.

How To Get a Solar Engineering Stamp

Some AHJs require ink or an embossed stamp on paper drawings. This involves using paper drawings for a project. However, if an AHJ merely requires engineer-approved drawings, the engineer can often sign off on digital copies. Using digital sealing and e-signatures can save time, paper, and money over wet stamps when feasible.

Working with a PE is required to obtain wet stamps or digital engineer seals. Solar, battery storage, and EV charging station professionals often use a professional service to meet this requirement. Pricing varies for engineering services and usually depends on how many drawings require engineering stamps.

GreenLancer offers engineering review services, including reviewing permit plan sets and PE seals for an AHJ. In addition, GreenLancer offers electrical, structural, and civil analysis, digital stamps, and wet stamps from licensed professional engineers for solar energy, EV charging stations, and generator projects.

What are the Licensing Requirements for a PE Stamp?

Licensing requirements for obtaining a PE (Professional Engineer) stamp vary by state and jurisdiction, but there are some common requirements that most engineers must meet in order 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 need to pass the Fundamentals of Engineering (FE) exam and the Principles and Practice of Engineering (PE) exam. 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 are offering 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 be aware of 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 Are PE Stamps Required For Solar 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.

Engineering Wet Stamps: Critical For Some Solar & EVC Projects

If engineering stamps are needed for a project, it’s essential to provide them 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.


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