As a key structure supporting photovoltaic modules, photovoltaic supports directly affect system safety, power generation, and investment returns:
1. Type and characteristics of stent
Support type  Structural features  Power generation improvement  Applicable scenarios  Cost comparison
Fixed type: The angle of the component remains unchanged. Benchmark (0%): For most scenarios, cost-sensitive projects. Lowest cost
Adjustable tilt angle, manually adjustable (seasonally), approximately 5%, suitable for small and medium-sized power stations in areas where manual maintenance is convenient, low
Single-axis tracking type: Tracking the solar azimuth along the horizontal axis. 15%-25%. Large-scale ground-mounted solar power stations, east-west oriented areas. Medium to high
Dual-axis tracking type  Omnidirectional tracking of solar position  25%-40%  High-latitude regions, high-value projects  Highest
2. Main materials and selection
Hot-dip galvanized steel bracket: high strength, corrosion resistance, lifespan of 25 years or more, the most widely used, moderate cost
Aluminum alloy bracket: light weight, aesthetically pleasing, suitable for roofs and lightweight scenarios, but with higher cost
Composite material bracket: such as carbon fiber, lightweight, high strength, but expensive, mainly used in special scenarios
Plastic bracket: low cost, good insulation, but limited strength, suitable only for small systems
3. Design essentials and calculations
Wind load calculation: Based on the local wind speed with a 50-year return period, calculate the wind pressure distribution and determine the wind resistance capacity of the support (usually ≥25m/s)
Snow load calculation: Based on the local snow thickness and density, design the bearing capacity of the support (especially important in northern regions)
Basic design:
Pile foundation scheme: screw pile (suitable for soft soil), cast-in-place concrete pile (suitable for hard geology), with good stability
Counterweight scheme: Concrete block counterweight, featuring simple construction, is suitable for areas with weak roof and ground bearing capacity
Span design: The flexible support can achieve a large span of 18-60m, with the space underneath being utilized for agricultural planting, thereby enhancing land utilization efficiency
4. Special scene applications
Roof bracket: For flat roofs (counterweight type), sloping roofs (hook type), and color steel plate roofs (clamp type), waterproofing and load-bearing capacity need to be considered
Floating support on water surface: It adopts high-density polyethylene float to adapt to water level changes, does not occupy land, and is suitable for lakes and reservoirs
Agricultural greenhouse support: The height is usually ≥3m, meeting the requirements of agricultural machinery operations, enabling "power generation above the greenhouse and planting below the greenhouse"
BIPV dedicated bracket: perfectly integrated with the building, combining aesthetics and power generation functions, with a minimum curvature radius of 5m
Selection suggestions: For large-scale ground-mounted solar power plants, priority should be given to single-axis tracking (the best cost-performance ratio); for rooftop projects, steel or aluminum alloy should be selected based on the load-bearing capacity; for high-latitude regions, dual-axis tracking can be considered; and for agricultural photovoltaic projects, large-span flexible supports are recommended
IV. Photovoltaic modules and inverters: The "heart" and "brain" of the photovoltaic system
Photovoltaic (PV) modules and inverters are the core equipment of a PV system, and their selection and matching directly determine the system's performance and lifespan
1. Photovoltaic module types and selection
Comparison of mainstream technology routes:
Technical route Conversion efficiency Mass production status Temperature coefficient Applicable scenarios
PERC (Passivated Emitter Rear Cell) 22%-24% Mature, low cost General Large-scale ground-mounted power plants
TOPCon (Tunnel Oxide Passivated Contact) 24%-26% Mainstream, 83% of production capacity Good High-efficiency ground-mounted power stations, distributed
HJT (Heterojunction Solar Cell) 25%-27% Growing, high cost Best (-0.25%/℃) High value-added project, low light environment
XBC (back-contact cell) 26%+ High-end market, 20% capacity Good Distributed, high aesthetic requirements scenarios
Detailed explanation of component parameters:
Maximum power (Pmax): The maximum output power under standard test conditions (STC). By 2025, mainstream module power will reach 550-670W
Open-circuit voltage (Voc): The voltage of a module when there is no load, which affects inverter selection and the number of modules connected in series
Short-circuit current (Isc): The current of a component under short-circuit conditions, which determines the system protection design
Temperature coefficient: percentage of power decrease per 1℃ increase in temperature, with HJT having the lowest (-0.25%) and PERC having a higher (-0.38%)
Double-sided efficiency: The ratio of power generation capacity on the back side to that on the front side. High-quality double-sided modules can achieve a double-sided efficiency of 85% or higher, which can increase power generation by 10%-15%
2. Inverter selection and matching
Inverter types and applicable scenarios:
Inverter type Topology Efficiency Applicable scenarios Advantages
String inverter: Multiple strings of modules correspond to one inverter. 97%-99%. Distributed photovoltaic (≤1MW). High MPPT accuracy, minimal impact from faults
Centralized inverter: After connecting multiple strings in parallel, it is then connected to a high-power inverter. The efficiency is 96%-98%. This is suitable for large-scale ground-mounted solar power stations (10MW+). It offers low cost and simple maintenance
Centralized and distributed inverter "String MPPT + Centralized inverter" 97%-99% Medium-sized ground-mounted power station (1-10MW) Balancing efficiency and cost
Micro-inverter: One inverter for each single module. 95%-97%. High-end residential areas with high aesthetic requirements. High safety, no "cask effect"
3. Matching principle between components and inverters
Power matching: The rated power of the inverter should be ≥80% of the total power of the components (to account for losses) and ≤120% (to avoid long-term light loading)
Voltage matching: The total voltage of components connected in series should be within the MPPT voltage range of the inverter, typically 60%-90% of the inverter's rated voltage
Current matching: The sum of the short-circuit currents of the components should be ≤ the maximum input current of the inverter, usually with a 10% margin
4. System optimization and configuration
Module over-rating: In high-irradiance areas, the module power can be over-rated by 10%-30% compared to the inverter, improving system efficiency and reducing the cost per kilowatt-hour
MPPT configuration: When connecting multiple strings, it is advisable to connect strings with similar orientation/inclination to the same MPPT to reduce mismatch losses
Temperature management: The inverter should be installed in a well-ventilated location. For every 10℃ increase in temperature, its lifespan is halved and its efficiency decreases by 1%
Selection recommendations: For large-scale ground-mounted power stations, opt for centralized inverters paired with bifacial double-glass modules; for industrial and commercial rooftop installations, consider string inverters paired with high-efficiency monocrystalline modules; for residential systems, micro-inverters paired with half-cut modules can be considered to enhance safety and aesthetics