General Layout of Photovoltaic Modules and Floating Solar Power Plants

Introduction

This section focuses on the detailed layout of photovoltaic modules within floating solar power plants, specifically addressing the considerations for spacing calculations and the general arrangement of floats in floating systems.

Photovoltaic Module Spacing Calculations

The calculation of spacing between photovoltaic modules in the east-west and north-south directions for floating solar power plants is largely similar to ground-mounted installations. However, a key difference lies in the reference plane:

• Floating Solar Power Plants: The reference plane for spacing calculations is considered horizontal. There is no need to account for slopes as in ground-mounted installations.

Example: Consider a fixed floating solar power plant in Shangrao City, Jiangxi Province. This plant uses single-axis tracking photovoltaic supports with a slight tilt angle. The primary consideration during layout is the spacing between photovoltaic modules in the east-west direction. Calculations are performed to ensure no shadowing occurs between modules during local true solar time from 09:00 to 15:00. The resulting spacing between photovoltaic modules in the east-west direction is 7.5 m.

• North-South Spacing: In the north-south direction, shadowing is typically not a concern. It is usually sufficient to maintain a 1 m clearance for maintenance access.

Verification with Manufacturer: After calculating the spacing to avoid shadowing, it’s essential to submit these results to the photovoltaic module manufacturer for review and confirmation before proceeding with further design.

General Layout of Floats

Floating floating solar power plants, in addition to conventional equipment like photovoltaic modules, inverters, and transformers, consist of four main components:

• Floating System: This system supports the photovoltaic modules and other equipment.
• Anchoring System: This system secures the floats in place, resisting forces from wind, waves, and currents.
• Laying System: This system is responsible for the installation and routing of cables.
• Grounding System: This system ensures electrical grounding for safety purposes.

The general layout of the floats involves optimizing the arrangement of photovoltaic modules while considering factors beyond just avoiding shadowing. Key considerations include:

1. Maintenance Passages: Dedicated maintenance and operation passages must be provided for each photovoltaic module, inverter, combiner box, and cable within the photovoltaic array.
2. Collision Prevention: During extreme weather conditions, the float arrays should be positioned to prevent collisions even during maximum displacement.
3. Optimal Array Configuration: Prioritize large arrays, with smaller arrays used to supplement where necessary, based on the overall layout area.
4. Float Position and Anchoring: The float position should be designed to allow for water level fluctuations while preventing contact with the shore. The specific method of float anchoring (ballast, dedicated anchor, or pile) should be considered to ensure stability.
5. Cable Minimization: The float array layout should minimize the use of DC cables. Hydrodynamic calculations can be performed to determine the maximum deformation of the float due to temperature changes. Fatigue analysis of the float connection nodes under wave forces should also be conducted. The float manufacturer can provide the design unit with the final float array layout (excluding waterways), after performing displacement calculations. The design unit then provides the manufacturer with specific requirements related to shadowing and waterway crossings.

Conclusión

The layout of photovoltaic modules and floats in floating solar power plants requires careful consideration of factors beyond simply avoiding shadowing. Ensuring proper spacing, providing adequate maintenance passages, and implementing robust anchoring systems are crucial for the safety and operational efficiency of these installations. The next section will delve into the design of specific components within floating solar power plants, focusing on the layout of waterways, transformer platforms, and other essential elements.