Whether you are building a transmission line, developing a solar farm, supplying components, or simply trying to understand how utility infrastructure works, it is essential to understand where design and construction standards come from.
At the Clean Energy Steel Construction Center (CES), much of our work sits at the intersection of clean energy deployment, utility infrastructure, and material performance. A recurring challenge across these markets is not a lack of standards, but a lack of clarity around how those standards fit together.
Most utilities maintain their own internal design and construction standards tailored to their operating philosophy, geography, climate, regulatory environment, and long-term goals. While these standards may appear highly utility-specific, they are almost always built on a shared foundation of national consensus codes.
For utility-scale clean energy projects and electric utility infrastructure, the core codes are ASTM, NESC, ASCE, IEEE, AMPP, and AWS. Each plays a distinct role. Together, they form a layered framework governing materials, safety, design, durability, fabrication, and electrical performance.
The Utility Code Framework, in Plain Terms
Utility codes are best understood as a system of layers rather than standalone documents.
Some codes establish baseline requirements, defining acceptable materials and minimum safety expectations. Others build on that foundation by providing engineering methods, durability guidance, fabrication rules, and electrical performance criteria. Utilities then bring all of this together through their internal standards and contracts.
This layered structure explains why utility standards can appear complex, while still tracing back to a relatively small set of foundational codes.
At a high level:
- ASTM and NESC establish baseline criteria
- AMPP and AWS connect materials to execution and long-term performance
- ASCE and IEEE translate requirements into structural and electrical design
American Society for Testing and Materials (ASTM), Defining Materials
the material foundation of utility and clean energy infrastructure. They define what materials are and how they are verified, not how systems are designed.
In utility applications, pertinent ASTM specifications answer material-level questions such as:
- What chemical and mechanical properties are required
- How thick a galvanized coating must be
- How materials are tested, inspected, and repaired
Common ASTM standards referenced in utility and clean energy infrastructure include:
- ASTM A572 – Structural steel specifications
- ASTM A123 – Hot-dip galvanizing of fabricated steel
- ASTM A153 – Hot-dip galvanizing of hardware
- ASTM A780 – Repair of damaged galvanized coatings
ASTM defines the material reality that all downstream design assumptions rely on.
National Electrical Safety Code (NESC), Defining System Safety
If ASTM standards define the materials used in utility infrastructure, the National Electrical Safety Code defines how the overall system must perform safely. NESC is not a traditional design manual, but a set of baseline safety and performance requirements.
NESC establishes requirements related to:
- Minimum electrical clearances
- Wind, ice, and temperature loading conditions
- Strength and safety factors for structures and hardware
- Construction, operation, and maintenance practices
Typical NESC sections referenced in utility design and construction include:
- Section 23 – Electrical clearances
- Section 25 – Strength and loading requirements
- Section 26 – Construction specifications
Unlike many technical standards, NESC is frequently adopted directly by regulators and state public utility commissions and is widely treated as the standard of care.
Clarifying note:
The National Electrical Safety Code is published by the Institute of Electrical and Electronics Engineers (IEEE) but is distinct from IEEE technical standards. It should also not be confused with the National Electrical Code (NEC), which is published by the National Fire Protection Association (NFPA) and applies primarily to residential, commercial, and industrial building wiring rather than utility infrastructure.
Association for Materials Protection and Performance (AMPP), Defining Durability
AMPP standards bridge materials and long-term performance. While ASTM defines material properties and establishes conformance, AMPP standards focus on corrosion control and asset protection.
For clean energy infrastructure exposed to aggressive or variable environments, AMPP guidance often informs maintenance strategies, risk management, and life-cycle cost decisions.
Common AMPP standards referenced in utility and clean energy applications include:
- AMPP SP0169 – Corrosion control of buried and submerged metallic systems
- AMPP SP0188 – Coating discontinuity (holiday) testing
Clarifying note:
Historically, corrosion guidance developed by NACE International (now AMPP) has been incorporated into IEEE standards, which is why AMPP concepts often appear in electrical requirements even when not explicitly referenced.
American Welding Society (AWS), Defining Welding Requirements for Steel Construction
The American Welding Society governs how steel structures are welded, most commonly through AWS D1.1.
AWS standards define:
- Welding procedures
- Welder qualifications
- Inspection and acceptance criteria
Common AWS standards referenced in utility and clean energy infrastructure include:
- AWS D1.1 – Structural welding code for steel
AWS ensures that ASTM-qualified materials are assembled into structures capable of meeting safety and performance expectations.
American Society of Civil Engineers (ASCE), Defining Structural Design
The American Society of Civil Engineers provides the engineering methods used to design structures that meet NESC safety requirements.
ASCE standards define:
- Environmental loads
- Load combinations
- Structural analysis methods
- Specialty guidance for specific structure types
Common ASCE standards used in utility and clean energy projects include:
- ASCE 7 – Minimum design loads for buildings and other structures
- ASCE 48 – Design of steel transmission pole structures
- ASCE 74 – Structural loading criteria for overhead transmission lines
These standards strongly influence structure geometry, steel tonnage, and foundation design.
Institute of Electrical and Electronics Engineers (IEEE), Defining Electrical Performance
The Institute of Electrical and Electronics Engineers governs electrical performance requirements across power systems.
IEEE standards address:
- Electrical clearances and insulation coordination
- Grounding and bonding
- Substations and equipment interfaces
- System behavior under normal and fault conditions
Common IEEE standards referenced in utility and clean energy infrastructure include:
- IEEE 524 – Installation practices for overhead transmission line conductors
- IEEE 80 and IEEE 2778 – Grounding system design for utility infrastructure, including distribution, transmission, substations (IEEE 80), and utility-scale, ground-mounted photovoltaic plants (IEEE 2778)
- IEEE 1547 and IEEE 2800 – Interconnection and performance requirements for solar, wind, and battery storage resources connecting to distribution systems (IEEE 1547) and transmission or sub transmission systems (IEEE 2800)
While IEEE does not define structural strength, its requirements frequently influence structure height, configuration, and foundation design.
Are There Other Codes?
Yes, but most sit on top of this framework rather than replacing it.
Standards from the American Institute of Steel Construction (AISC) may apply to substations or framed structures. Specifications from the USDA Rural Utilities Service bundle existing codes for rural utilities. Codes from the National Fire Protection Association apply to buildings, substations, and energy storage systems.
These documents apply the core framework to specific cases. They do not redefine it.
Why This Matters for Clean Energy
As clean energy infrastructure scales, projects are becoming larger, faster, and more interconnected. New materials and configurations are often introduced faster than codes evolve.
One of The CES’s core objectives is helping the industry understand how to work within this existing code framework to responsibly deploy durable, cost-effective, and scalable clean energy infrastructure, particularly where steel, coatings, and long-life construction play a central role.
Understanding which codes define the foundation and which simply apply it helps project teams reduce risk, avoid unnecessary conservatism, and introduce innovation responsibly. While utilities enforce requirements through their own standards and contracts, those requirements almost always trace back to this shared code framework.
Code Application Across Utility Infrastructure Types (with Typical Examples)
| Code Body | Distribution | Transmission / Sub-Transmission | Utility-Scale Solar |
| ASTM International | Steel poles, crossarms, hardware, anchors, galvanizing | Poles, lattice towers, monopoles, foundations, hardware, galvanizing | Solar piles, racking, anchor bolts, galvanizing |
| Typical examples | ASTM A572, A588, A123, A153, A780 | ASTM A572, A588, A123, F3125, A780 | ASTM A572, A500, A123, A780 |
| National Electrical Safety Code | Primary governing code for loads, clearances, safety | Primary governing code for loads, clearances, safety | Typically indirect via utility or EPC requirements |
| Typical examples | NESC Section 21, 23, 25 | NESC Section 23, 25, 26 | Referenced via interconnection or utility standards |
| American Society of Civil Engineers | Core structural design authority | Core structural design authority | Core structural design authority |
| Typical examples | ASCE 7 (limited use), ASCE 48 | ASCE 7(limited use), ASCE 48, ASCE 74 | ASCE 7, specialty /solar guidance |
| Institute of Electrical and Electronics Engineers | Grounding, construction & installation practices, equipment interfaces | Grounding, construction & installation practices, equipment interfaces | Grounding, interconnection requirements |
| Typical examples | IEEE 80, IEEE 524 | IEEE 80, IEEE 524 | IEEE 2778, IEEE 1547, IEEE 2800 |
| Association for Materials Protection and Performance* | Embedded steel, soil exposure, coatings, corrosion control | Diverse environments, long service life, coatings, corrosion control | Aggressive soils, coastal and agricultural sites |
| Typical examples | AMPP SP0169, SP0188, SP0215, SP0315, SP0415, SP21459 | AMPP SP0169, 2, SP0188, SP0215, SP0315, SP0415, SP21459 | AMPP , SP0188, corrosion guides |
| American Welding Society | Fabrication of welded poles, hardware, attachments | Fabrication of welded towers, monopoles, connections | Fabrication of welded piles, racking, towers |
| Typical examples | AWS D1.1 | AWS D1.1 | AWS D1.1 |
About the Clean Energy Steel Construction Center (CES)
The Clean Energy Steel Construction Center is an industry-led initiative focused on advancing the use of durable, cost-effective, and sustainable steel solutions in clean energy and utility infrastructure. CES works across transmission, distribution, solar, wind, and emerging energy markets through education, research, and collaboration to support long-life infrastructure solutions.
About the Author
Jeff Suda is an experienced trade association leader and utility industry professional with deep expertise in electric utility infrastructure, code standards, and clean energy deployment. He serves as a founding leader of CES and has led industry coalitions that bridge technical, regulatory, and commercial stakeholders to clarify and improve utility design and construction standards. Jeff’s work focuses on helping technical and non-technical audiences understand complex systems and how their application across distribution, transmission, and renewable energy infrastructure. He regularly writes and speaks on topics where materials performance, structural design, and electrical standards intersect in utility and clean energy projects.