Critical Mistakes to Avoid in Planning Ground-Mounted Solar PV System Layouts

The success of a ground-mounted solar photovoltaic (PV) system largely hinges on its layout design. Proper planning of the site, shading, spacing, orientation, and infrastructure can significantly enhance the system's performance and efficiency. However, several common mistakes can impede optimal system performance. In this article, we will explore these errors and provide actionable solutions to help you design an efficient ground-mounted solar PV system.

Ignoring Shading Issues

Shading can severely impact the performance of a solar PV system. Incorrect panel placement due to nearby obstacles like trees, buildings, or other structures can lead to partial or sporadic shading. This can cause the system to produce less power than expected.

Solution:

Perform a Shading Study: Conduct a thorough shading assessment that considers seasonal variations in sunlight to find the best panel placements. Remove Vegetation or Use Instruments: Eliminate obstacles by removing vegetation or use tools like solar pathfinders to improve exposure.

Insufficient Space Between Rows

When solar panels are arranged too closely, shading between them can occur, especially during winter months when the sun's angle is lower. This can significantly decrease the system's efficiency.

Solution:

Determine Row Spacing: Use seasonal solar angles and the site's latitude to establish the appropriate spacing. Prevent Shading During Peak Production: Maintain adequate space to avoid shading during the hours when the system operates at its maximum capacity, even in winter.

Inaccurate Tilt Angle and Orientation

The tilt angle and orientation of solar panels significantly affect their efficiency. Incorrect installation can lead to lower power generation.

Solution:

Aim for Correct Orientation: Generally, in the Northern Hemisphere, panels should face south and be tilted at an angle near the site's latitude. Local Adjustments: Adjust angles based on specific geographic requirements to maximize performance.

Poor Site Selection and Infrastructure

Choosing a suitable site and ensuring proper infrastructure are crucial. Unsuitable terrain, improper soil conditions, and flood-prone areas can impact the system's stability and performance.

Solution:

Geotechnical Analysis: Conduct a soil stability and drainage assessment. Secure Foundations: Use elevated mounting or reinforced foundations if the site is prone to flooding or erosion.

Non-Effective Cable Management and Trenching

Inefficient cable routing can lead to long distances between panels, combiner boxes, and the inverter. This can result in power losses and increased costs.

Solution:

Minimize Cable Runs: Plan a layout that reduces voltage drop and installation expenses. Protect Cables: Install conduits underground or on racks to safeguard cables from environmental and mechanical hazards.

Overlooking Maintenance Accessibility

A poorly planned layout can hinder maintenance and repairs, increasing the risk of system downtime and decreased efficiency.

Solution:

Safe Access: Ensure proper spacing between rows and around the perimeter to allow safe and easy access for maintenance. Regular Inspections: Leave sufficient space for larger systems where regular cleaning and inspections are crucial.

Non-Compliance with Local Regulations

Installing a solar PV system without verifying local permitting and zoning requirements can lead to legal issues, fines, or system redesigns.

Solution:

Early Research: Investigate zoning laws, setbacks, and permitting requirements during the design phase. Compliance: Ensure that the system adheres to local regulations, which may restrict system height, visual impact, and proximity to property boundaries.

Insufficient Wind Load Consideration

Failing to account for wind loads can lead to damage to panels and mounting structures in high-wind areas.

Solution:

Historical Wind Data: Design the mounting structure to withstand local wind speeds based on historic data. Reinforcement: Reinforce the mounting structure if necessary, especially for installations in coastal or open-field areas with high wind speeds.

Underestimating Future Expansion Needs

Not planning for potential system expansion or upgrades can be costly and complex.

Solution:

Flexible Design: Design a layout that allows for additional panels in the future. Ensure that the initial design accommodates any expansions. Ease of Expansion: Leaving space in the initial design can simplify any future expansions.

Incorrect Snow Load Considerations

Ignoring snow load requirements can be hazardous in regions with significant snowfall, leading to structural risks or performance issues.

Solution:

Building Codes Compliance: Ensure that the racking and mounting system can support local snow load requirements. Steeper Tilt Angles: Consider a steeper tilt angle to help snow slide off the panels more easily.

Insufficient Security Measures

Failing to implement security features makes the system vulnerable to theft or vandalism, especially in remote or public-accessible areas.

Solution:

Fencing and Surveillance: Install security fencing, cameras, or lighting around the solar array.

Incorrect Inverter Placement

Placing inverters too far from the panels can reduce efficiency, increase power losses, and expose them to harsh environmental conditions.

Solution:

Nearby Placement: Position inverters close to the panels while maintaining good ventilation and weather protection. Centralized Stations: Some ground-mounted systems may benefit from centralized inverter stations.

By carefully avoiding these common mistakes, you can ensure the efficient planning and installation of your ground-mounted solar PV system. Proper design and maintenance can lead to long-term savings and a sustainable energy solution for your property.