The solar industry is booming. With over 4.2 million American homes now powered by the sun and an average of 25-30 panels per rooftop , the residential solar market is experiencing unprecedented growth. This surge in demand has intensified competition among solar installers, emphasizing the need for expertise in all aspects of solar project management, including a thorough understanding of solar plan sets.
Whether you're a contractor planning your next solar project, an EPC managing multiple panel installations, or a homeowner dreaming of solar power, you've come to the right place.
How to Read a (Residential and Commercial) Solar Plan Set
Solar plan sets are blueprints that outline the exact layout and specifications for your PV system installation. They contain detailed information about every aspect of the installation, from the location of solar panels to the electrical wiring. That being said, let's split this comprehensive document into nine key components:
The site plan is your first reference point. It gives you a complete visualization of the installation site. Want the bird's eye perspective of your property? That's essentially what a site plan offers. It outlines the arrangement of buildings, pathways, and other key features;
• Dimensions: This section details the exact measurements of the site, helping you understand the spatial constraints and opportunities. Now, why is this important? Because accurate dimensions ensure that all equipment fits perfectly within the designated space.
• Equipment: Here, you'll find the planned locations for solar panels, inverters, and other essential components. Knowing where everything will be placed helps in visualizing the final setup and planning any necessary adjustments.
• The Roof of a Building: The roof's layout and structure are critical for placing solar panels. A detailed roof plan will show slopes, materials, and any potential obstructions.
The PV layout precisely outlines the solar panel’s actual configuration on the roof. This drawing provides valuable insights into:
• Panel Quantity: Knowing how many panels will be placed helps estimate your system's energy output and efficiency. For example, a rooftop with 20 panels will generate different power levels than one with 50 panels.
• Fire Setbacks: These are safety regulations that dictate the minimum distance between solar panels, and property lines or structures. Adhering to these setbacks is crucial for ensuring fire safety and facilitating maintenance.
Structural plans detail how the solar panels will be securely mounted to withstand various loads. It gives you information on the mechanical aspects of a solar installation such as:
• Attachment/Mounting Details: These plans outline how the solar panels will be attached to your roof. You'll find information about the type of mounting system (e.g., ballasted, roof penetration) and the specific attachment points.
• Details of the Structural Elements: The information about the structural members for mounting the solar panels is also derived from the solar plan set. This details the dimensions and specifications of brackets, rails, and other mounting components.
• Load Bearing Capacity Analysis: Loads are typically the different types of weights that act on or towards the solar systems; primarily categorized under two categories: Live loads and Dead loads. The former refers to temporary forces like wind, snow, and seismic, while dead loads are the actual, permanent weight of the solar panels itself.
The string layout shows the electrical connections between panels and inverters to better understand power flow.
• Panel-wise Connection: Which panel is connected to which panel is shown in the string layout. Insights on this configuration help diagnose potential issues and optimize performance.
• String to MPPT Connection: Maximum Power Point Tracking (MPPT) ensures that each string operates at its optimal efficiency, maximizing the overall energy output. You can identify which string is connected to which MPPT of an inverter.
Single Line Diagrams (SLDs) and Three Line Diagrams (TLDs) are electrical schematics that show the power flow from the solar panels to the grid. They provide essential information about:
• Electrical Pathway: These diagrams map out the electrical pathway from the panels to the grid or storage, giving us information on where the power flows.
• Power Distribution: SLD and TLD give data about switch gears and cabling requirements for system protection. Proper switch gears and cables are crucial for safeguarding the system against faults and overloads.
• Interconnection: The interconnection strategy used during design is depicted in SLD / TLD. This shows how different system components are connected, ensuring seamless power flow.
• Protection Devices: These diagrams indicate the location of safety devices like circuit breakers, fuses, and fault currents for each panel board. This helps you understand and design appropriate protective measures.
• Conduit Schedule: The SLD / TLD ultimately provides information about the conduit schedule, including the routing of electrical conduits, to ensure neat and safe installations.
Equipment elevation drawings detail the physical placement of components in 3D. They show:
• How the System is Positioned and Spaced: Component positions: The exact location of inverters, racking systems, and other equipment is clearly depicted to balance ventilation with safety. Inverters, for instance, need adequate airflow to prevent overheating.
• How the conduits are routed on the walls: This helps in planning efficient and aesthetic conduit runs.
• How the wire gutters are placed on the walls: The path of electrical conduits and wire gutters is outlined, providing a clear picture of the system's wiring. Wire gutters organize and protect electrical wiring, maintaining a tidy installation.
Being the backbone for a solar plan set, the calculations ensure the system's electrical components are appropriately sized based on 2 aspects: Current and Power.
• Cable (based on electric current): The current rating of cables ensures they can handle the electrical load without overheating.
• Switch Gears (based on electric current): Properly rated switch gears protect the system from overcurrent situations.
• Conduit Sizing (based on electric power): Conduit size is determined by the power the cables carry, ensuring safe and efficient electricity flow.
Solar plan sets include labels and placards to ensure safety and compliance. These elements provide:
• Warning signs: System precautions and important safety instructions are properly communicated on this page.
• Applicable standards: Compliance with standards like NEC or IEC ensures the system meets industry norms for safety and performance.
• Color Coding: Identify different components and their functions with standardized color codes.
This is the final section of the entire solar plan set that includes technical documents for all major components.
• OEM datasheet: The last step of dispatch is attaching the OEM (Original Equipment Manufacturer) datasheet together with the solar plan set. These datasheets provide detailed specs such as performance ratings, dimensions, and warranties, along with performance metrics for solar panels, inverters, and other equipment.
The solar industry is undergoing a rapid transformation. 10 years back, only three states had installed over 1 gigawatt of solar power in the US. Today, that number has soared to 30. With this explosive growth comes increased competition. To stay competitive, mastering the nuances of solar installations is essential. And knowledge of solar plan sets is one major piece of the puzzle that ensures project success and gains a competitive edge!
Reading a solar plan set might seem daunting at first. But dissecting it into these nine sections makes it manageable. Each component provides vital information that contributes to the overall success of the solar installation.
So next time you encounter a solar plan set, you'll know exactly what to look for and how to interpret the details!
Should you require additional support in interpreting your solar plan set, our expertise will assist you right away.
