The solar energy industry faces various challenges, including trade wars, national policies, grid connection conditions, and more. Installers and plant owners worry about the profitability of photovoltaic (PV) power stations, solar product manufacturers are concerned about the lack of favorable policies, and grid facility manufacturers are apprehensive about meeting technical standards. Ultimately, the core question lies in whether the power output of PV stations can meet operational and profitability demands and how to generate more electricity.
Industry experts point out that current solar power generation requires addressing multiple issues, such as real-time weather monitoring, load detection for distributed and centralized power generation, energy storage, the development of next-generation smart inverters, comprehensive power quality monitoring and control, as well as management in engineering, design, operation, and maintenance.
This article briefly analyzes factors affecting PV power generation from the perspectives of construction quality, optimization design (e.g., ideal tilt angles), and equipment such as modules and combiner boxes.
1. Construction Quality
Some installers, driven by profit, blindly reduce construction costs, resulting in quality issues that may cause a 3–6% loss in power generation.
Chen Lei, manager of the New Energy Power Generation Division at State Grid Smart Research Institute, highlighted in a forum that companies must adopt refined management practices to prevent project delays, select appropriate and qualified materials to ensure quality, and conduct regular maintenance and supervision to guarantee the proper functioning of PV stations.
For the installation of building-integrated PV systems, a construction organization plan and quality control procedures should be prepared. Corresponding construction schemes and safety measures should also be formulated, with feasibility assessments conducted when necessary.
2. Optimization Design
The goal of system optimization is to maximize power generation by assessing factors such as solar irradiance, light reflectivity, ambient temperature, wind conditions, and the performance and interaction of various system components. A lack of optimization design in some PV plants leads to reduced power output.
Key design considerations include:
Shading: Shading significantly affects system efficiency, induces thermal stress, and reduces module lifespan. Types of shading include surrounding buildings, trees, self-shading from the PV system itself, and temporary shading caused by dust.
Orientation and Tilt Angle: Calculating the optimal tilt angle is essential, as grid-connected or off-grid systems require different designs. For grid-connected systems, the tilt angle should maximize the annual average daily power output, while off-grid systems may prioritize summer or winter loads.
For example, in Nanjing:
Grid-connected systems achieve maximum annual power output at a tilt angle of 25°, about 7° less than the local latitude.
Off-grid systems vary: for summer loads, the optimal tilt angle is 7°, far below the local latitude; for winter loads, it is 46°, much higher than the local latitude; for balanced loads, a tilt angle of 42° is recommended.
3. Equipment
Key equipment affecting power generation in PV plants includes solar modules, combiner boxes, inverters, and grid infrastructure.
Solar Modules
During module selection and system construction, optimizing compatibility and using a mix of Grade A and Grade B solar cells can improve efficiency. Module quality must be ensured, with careful consideration of factors such as latitude, spectrum, temperature, shading, location, and wiring conditions, all of which influence module performance.
Inverters
Inverters are the only equipment, apart from modules, that can directly improve power generation efficiency—potentially by up to 10%. Before installation, State Grid recommends conducting simulation experiments and focusing on cost reduction through batch production rather than solely pursuing low-cost manufacturing.
Grid Connection
Grid connection remains a significant challenge for China’s solar power systems, which are still in the early stages of development. Mismatches between system designs and the grid, along with the issue of full-grid absorption, hinder efficiency. Experts suggest prioritizing local power consumption to reduce grid load and building infrastructure such as EV charging stations to lower transmission costs.
Through comprehensive management of construction quality, system optimization, and equipment selection, the photovoltaic industry can enhance power generation efficiency and better meet operational and profitability requirements.
