The principles, functions and future challenges of solar photovoltaic power generation

1. Principle of photovoltaic power generation: "magic conversion" of light and electricity
The core of photovoltaic power generation is the photovoltaic effect, that is, after the semiconductor material absorbs sunlight, it stimulates electron transition and generates current. Its core structure is a PN junction, which is composed of P-type silicon (mainly holes) and N-type silicon (mainly electrons). When sunlight shines on the PN junction, the energy of photons causes electrons to break away from atomic bonds to form free electron-hole pairs. The built-in electric field drives electrons to move to the N region and holes to the P region, thereby forming a current in the external circuit.

The key to this process lies in material optimization:
Single-crystalline silicon has a significantly better photoelectric conversion efficiency (about 22%-26%) than polycrystalline silicon due to its high lattice integrity and few impurities;
Passivation technology (such as Al₂O₃, SiNx coating) can reduce carrier recombination, increase minority carrier lifetime, and gradually commercialize high-efficiency battery technologies such as TOPCon and HJT.

2. The role of photovoltaic power generation: from environmental protection to economic transformation
Environmental benefits: the "green engine" of zero-carbon electricity
Photovoltaic power generation has no greenhouse gas emissions throughout the process, and can reduce hundreds of millions of tons of carbon dioxide each year compared to thermal power. Taking China as an example, the installed capacity of photovoltaic power in 2023 will reach 216.3 GW, accounting for nearly 40% of the global total, and the annual emission reduction effect is equivalent to planting hundreds of millions of trees.
Economic value: Energy independence and industrial upgrading
Cost reduction: In 2009, the price of photovoltaic electricity was about 1 yuan/kWh, and it dropped to below 0.2 yuan/kWh in 2023, which is significantly on par with thermal power;
Industry chain advantages: China dominates the global photovoltaic supply chain, with silicon wafers, batteries, and components accounting for more than 70% of the output, promoting new energy exports to become a new engine of economic growth.
Social empowerment: Rural revitalization and energy inclusion
Rural photovoltaic projects can reduce electricity bills and increase income through the "self-generation and self-use, surplus electricity to the grid" model. However, we need to be vigilant against criminals who promote inferior equipment in the name of "free installation", resulting in safety hazards such as line damage.

3. Technical Challenges and Innovation Breakthroughs
Efficiency bottleneck: optical and electrical losses
Optical loss: About 10%-20% of the incident light is not used due to reflection or grid line blocking. The reflectivity can be reduced to less than 5% through velvet structure and anti-reflection film (such as silicon nitride);
Electrical loss: Lattice defects induce carrier recombination. N-type silicon-based batteries (such as TOPCon) have a 1%-2% increase in efficiency compared with P-type batteries due to their long minority carrier lifetime.
Environmental adaptability: Sharp drop in power generation in winter
Low temperatures in winter increase battery resistance, and haze and snow further weaken light intensity.
Solutions include:
Tilt optimization: Adjust the angle of photovoltaic panels according to latitude to maximize the absorption of incident light in winter;
Energy storage matching: Use lithium-ion or zinc-air battery energy storage systems to smooth day and night and seasonal fluctuations.
Energy storage synergy: The auxiliary role of manganese dioxide catalysts
In the field of photovoltaic matching energy storage, manganese dioxide catalysts improve efficiency by optimizing electrochemical reaction paths. For example:
Zinc-air battery: crystalline/amorphous hybrid manganese dioxide catalyst can reduce the oxygen reduction overpotential, extend the cycle life to more than 3,000 times, and help power supply at night or on cloudy days;
Aqueous zinc battery: The phosphate proton reservoir strategy enables the manganese dioxide positive electrode to achieve two-electron transfer, and the discharge voltage is increased to 1.75V, providing high stability support for photovoltaic energy storage systems.

IV. Future Outlook: Technology Integration and Policy Drive
Perovskite-silicon stacked battery: Theoretical efficiency exceeds 35%, and is expected to break through the limit of single-junction batteries;
Intelligent operation and maintenance: AI algorithms monitor the health status of components in real time, predict cleaning and maintenance cycles, and improve power generation efficiency by 10%-15%;
Policy coordination: Improve distributed photovoltaic grid-connected standards and promote multi-scenario applications of "photovoltaic + agriculture" and "photovoltaic + construction".

Conclusion

Solar photovoltaic power generation is not only the "main force" of the energy revolution, but also a key path to respond to the climate crisis. From principle innovation to energy storage synergy, from cost optimization to policy empowerment, its development context confirms the power of "technology for good". In the future, with breakthroughs in auxiliary technologies such as manganese dioxide catalysts, photovoltaic power generation will accelerate towards a new era of high efficiency, stability and universal benefits, injecting inexhaustible momentum into global sustainable development.

 author：Hazel
 date:2025-05-28