1.What is photovoltaic power generation? What is distributed photovoltaic power generation?
Photovoltaic power generation refers to the conversion of solar radiation directly into electrical energy. It is currently the mainstream method of solar power generation, so when people talk about solar power generation, they are often referring to photovoltaic power generation. Distributed power generation refers to the construction of photovoltaic facilities near user sites. The operation of these facilities primarily focuses on self-use by the users, with excess electricity being sent to the grid. Distributed power generation follows the principles of adapting to local conditions, being clean and efficient, having a decentralized layout, and utilizing solar resources in proximity to reduce reliance on fossil fuels.
2.How do photovoltaic cells generate electricity?
Photovoltaic cells are semiconductor devices that possess the characteristics of converting light into electricity. They directly convert solar radiation into direct current (DC) electricity. Photovoltaic cells use special semiconductor materials, such as silicon doped with elements like phosphorus or boron, to create a permanent imbalance of charge within the material’s molecular structure. When sunlight shines on a semiconductor with these special electrical properties, it generates free charges that move in a specific direction and accumulate. When the ends of the semiconductor are connected, it produces electrical energy—an effect known as the “photovoltaic effect” or “solar cell effect.”
3.What components make up a photovoltaic power generation system?
A photovoltaic power generation system consists of several components, including a photovoltaic array (composed of interconnected photovoltaic modules), a controller, a battery bank, and a DC/AC inverter. The core component of a photovoltaic power generation system is the photovoltaic module, which is made up of interconnected photovoltaic cells encapsulated together. It directly converts solar energy into DC electricity. The electricity generated by photovoltaic modules can be used immediately or converted into AC electricity using inverters. Alternatively, it can be stored in energy storage devices like batteries for later use, depending on the immediate requirements.
4.Why is photovoltaic power considered a green and low-carbon energy source?
Photovoltaic power generation offers significant energy, environmental, and economic benefits, making it one of the cleanest energy sources available. By installing a 1 kilowatt photovoltaic system under average sunlight conditions in China, it can generate around 1,200 kilowatt-hours of electricity per year. This can reduce coal consumption (in terms of standard coal) by approximately 400 kilograms and decrease carbon dioxide emissions by approximately 1 ton. According to research conducted by the World Wide Fund for Nature (WWF), installing 1 square meter of photovoltaic system is equivalent to planting trees across 100 square meters in terms of reducing carbon dioxide emissions. Developing photovoltaic power generation and other renewable energy sources is one of the effective means to fundamentally address environmental issues such as smog and acid rain.
5. How much solar energy can we harness, and can it become the dominant energy source in the future?
The solar energy received on Earth’s surface is 10,000 times the global energy demand. The amount of radiation received per square meter per year varies between 1,000 and 2,000 kilowatt-hours, depending on the geographical location. According to data from the International Energy Agency, installing solar photovoltaic systems on just 4% of global deserts would be sufficient to meet global energy demand. Solar energy has vast development potential, and its prospects are enormous. Preliminary estimates indicate that in China alone, harnessing the existing buildings for photovoltaic installation has a market potential of over 3 trillion kilowatts. Additionally, the vast Gobi Desert in western China has a market potential of over 100 million kilowatts. With advancements in photovoltaic technology and large-scale application, the cost of solar power generation will further decrease, making it a more competitive energy supply option. Solar power is gradually transitioning from a supplementary energy source to a replacement energy source and holds the promise of becoming the dominant energy source in the future.
Post time: Jul-27-2023