As I reflect on the global energy landscape, it becomes evident that traditional fossil fuel-based power generation is increasingly inadequate to meet humanity’s growing demands. The finite reserves of these fuels, coupled with worsening environmental conditions, have intensified the focus on sustainable energy solutions. Solar power systems stand out due to their infinite availability, universal accessibility, cleanliness, and cost-effectiveness, making high-efficiency solar energy development a pivotal strategy for addressing worldwide energy challenges. According to reports, secondary energy sources currently dominate storage capacities, accounting for over 99% of reserves, while renewables like solar constitute less than 1%. However, the future of energy will inevitably rely on solar-based solutions. DNV GL’s analysis indicates that electricity must expand to 2.5 times its current production capacity to satisfy developmental needs, with solar power systems expected to peak in installed capacity by mid-century, reaching approximately 65 times today’s levels. By 2030, solar power systems could contribute up to 40% of global electricity annually, equating to around 19 terawatts, while fossil fuel-based generation diminishes. The maturation of photovoltaic technology and reduced investments in solar mounting structures, driven by policy support and technological breakthroughs, have propelled solar power systems to the forefront. For instance, production data from 2018 showed a 27.1% year-on-year increase in output from photovoltaic enterprises, with export values rising by 28.1%, despite price drops in components like polysilicon and monocrystalline modules.
The evolution of tracking mechanisms within solar power systems has been remarkable. Internationally, research into solar tracking devices began early, driven by escalating electricity demands and scientific progress. In 1994, the first tracking-system-equipped kitchen in Grossburg demonstrated practical applications, paving the way for innovations. By 1996, a system in Cyprus utilized DC motors and gear reducers with photoresistors to automatically adjust panel angles based on light intensity, cloud cover, and day-night cycles, transmitting signals to electronic controls. In 2002, an aluminum-based motor-controlled tracking system emerged in California, followed by a closed-loop servo system developed by researchers in Chile and Brazil in 2004. By 2008, China introduced a computer-controlled, integrated opto-mechanical-electrical tracking system capable of 24-hour operation. A significant advancement came with the redundant single-axis tracker, which incorporated bidirectional backups for control systems and drive motors. This design ensures operational continuity during failures by switching to backup components, thereby reducing maintenance costs and minimizing impacts on energy generation in solar power systems. The redundancy approach marks a breakthrough in enhancing the reliability of solar power systems.
Current trends in solar power systems highlight a shift toward single-axis tracking due to its structural simplicity and cost-effectiveness, whereas dual-axis systems, though more complex, offer higher solar energy utilization. Technological advancements are steering developments toward horizontal single-axis trackers, which employ astronomical algorithms in PLCs to compute sun positions and automate tracking, thereby extending exposure times and boosting efficiency. This progression underscores the importance of intelligent, automated solutions in solar power systems to maximize energy capture and adapt to dynamic environmental conditions.
The significance of these innovations cannot be overstated in the context of national and global energy strategies. Traditional fossil fuels and emerging renewables play crucial roles in sustainable development, but solar power systems, particularly those with advanced tracking, address critical issues of low energy efficiency and environmental degradation. Horizontal single-axis tracking systems enhance vertical sunlight reception, significantly increasing power output. Solar energy’s abundance is staggering; annual solar irradiation received by Earth exceeds the energy produced from all other sources by orders of magnitude, as confirmed by energy authorities. However, structural weaknesses in existing solar power systems often lead to deformations during installation or operation, reducing conversion efficiency. Additionally, resilience to harsh weather, such as strong winds, is essential. Horizontal single-axis trackers, with their compact design, high wind resistance, and full automation, effectively mitigate these challenges. Their promotion represents a transformative step for the photovoltaic industry, expanding solar energy applications and offering monumental benefits.
At the core of solar power systems is the photovoltaic effect, where silicon-based components convert light into electrical energy through PV conversion. This process enables basic electricity supply in off-grid areas and, in technologically advanced regions, complements other power generation methods to deliver stable energy. The photoelectric effect involves semiconductor-metal junctions generating potential differences under sunlight, creating electric fields in PN junctions that separate holes and electrons. When a forward bias is applied, the depletion layer narrows, allowing current flow. Minority carriers, or electron-hole pairs, play a key role in PV conversion, with holes accumulating in P-regions and electrons in N-regions. The inherent electric field pulls these carriers across the junction, forming a photoelectric field that counteracts the internal field, reduces the potential barrier, and produces an open-circuit voltage of about 0.5V.
Horizontal single-axis tracking systems utilize photoelectric tubes to adjust panel orientations based on solar altitude angles. When panels deviate from optimal alignment, current偏差 signals are amplified and fed to PLCs, which control stepper motors to recalibrate angles. While photoelectric sensors offer simplicity and high sensitivity, their efficiency can suffer in cloudy or rainy weather, leading to tracking errors. To address this, global positioning systems are integrated into these solar power systems, ensuring accuracy under varying conditions.
Cost analyses reveal that horizontal single-axis trackers in solar power systems incur higher initial expenses compared to fixed mounts. For example, the cost per watt for a horizontal single-axis structure is approximately $0.785, whereas fixed mounts cost less than 60% of that. Detailed cost comparisons are provided in Table 1. Based on a 1 MWp project in Ningxia, horizontal single-axis systems require about 3 more acres of land but use nearly half the number of pile foundations compared to fixed systems. The total cost difference per watt is $0.196. Simulations incorporating local meteorological data show that fixed systems generate around 1,440,000 kWh annually, while horizontal single-axis systems produce 1.22 times that amount, demonstrating the superior efficiency of advanced solar power systems.
The payback period and increased revenue for horizontal single-axis trackers in solar power systems can be calculated using specific formulas. The payback period formula is:
$$ \text{Payback Period} = \frac{\text{Total Cost of Horizontal Single-Axis Tracker} – \text{Total Cost of Fixed Tracker}}{(\text{Energy Output of Horizontal Single-Axis} – \text{Energy Output of Fixed}) \times \text{Local Feed-in Tariff}} – \text{Energy Output of Fixed} \times \text{Component Degradation Rate} \times \text{Feed-in Tariff} \times (10 – \text{Payback Years}) $$
For a 1 MWp capacity under local tariff conditions, the additional investment in horizontal single-axis solar power systems is recoverable in about 7 months, after which profits accumulate. Revenue projections over 25 years are as follows:
- Years 1–10: $$ (1,756,800 – 1,440,000) \times 0.94 \times 0.85 \times (10 – 0.7) = 2,354,045.76 \text{ units of currency} $$
- Years 11–15: $$ (1,756,800 – 1,440,000) \times 0.89 \times 0.85 \times (15 – 10) = 1,198,296 \text{ units of currency} $$
- Years 16–20: $$ (1,756,800 – 1,440,000) \times 0.86 \times 0.85 \times (20 – 15) = 1,157,904 \text{ units of currency} $$
- Years 21–25: $$ (1,756,800 – 1,440,000) \times 0.83 \times 0.85 \times (25 – 20) = 1,117,512 \text{ units of currency} $$
Overall, horizontal single-axis solar power systems can generate nearly 6 million more units of currency per 1 MWp over 25 years compared to fixed systems.
Key structural features of horizontal single-axis trackers in solar power systems include:
- Simplicity: Comprising photovoltaic modules, inverters, and PLC-based control units, these systems are lightweight, flexible, and highly coordinated.
- Low Energy Consumption: With multi-stage reduction protection, high减速 efficiency, and stable motor torque, daily operation lasts under 40 minutes, driven by less than 8W of power. Annual energy consumption per drive linkage is below 10 kWh, often powered directly by solar panels without external sources.
- Stability: Hot-dip galvanized components with zinc thickness exceeding 65μm ensure durability. Main beams and drive links use galvanized square tubes, meeting standards for resistance to bending and torsion.
- Low Failure Rate: Easy maintenance is facilitated by independently installed wearable parts, avoiding full disassembly.
- Additional Advantages:
- High pile foundations (minimum 2m clearance) with 7m × 6.3m spacing improve ventilation, preventing overheating-induced shutdowns in solar power systems.
- Wide rotation angles and automatic calibration reduce dust accumulation compared to fixed mounts.
- In snowy conditions, adjustable protective angles prevent snow buildup, maintaining efficiency.
| Mount Type | Foundation Piles (1 MW/units) | Foundation Specs | Length per Unit (m) | Material Cost ($/m) | Construction Cost ($/m) | Foundation Cost ($/W) | Structure Cost ($/W) | Installation Cost ($/W) | Total Cost ($/W) |
|---|---|---|---|---|---|---|---|---|---|
| Fixed | 660 | 300B | 5.5 | 105 | 10 | 0.417 | 0.45 | 0.15 | 1.017 |
| Horizontal Single-Axis | 360 | 300B | 5.5 | 105 | 10 | 0.228 | 0.785 | 0.2 | 1.213 |
In summary, horizontal single-axis tracking represents a groundbreaking innovation in solar power systems, significantly enhancing solar energy utilization. Under identical conditions, these systems yield 1.22 times the annual energy output of fixed mounts, offering superior cost-effectiveness and promising market prospects. Their high efficiency and moderate pricing position them as highly competitive in the evolving landscape of solar power systems, driving forward the renewable energy transition with robust, intelligent solutions.