Internationally, research on photovoltaic power generation technology has a history of more than 100 years. Photovoltaic power generation uses solar cells to convert solar energy directly into electrical energy based on the principle of photovoltaic effect. Photovoltaic systems can be divided into independent photovoltaic systems (various photovoltaic systems with independent operation of batteries) and grid-connected photovoltaic systems (photovoltaic systems connected to the grid and delivering electricity to the grid).
First, the advantages of photovoltaic power generation
Photovoltaic power has more advantages than traditional power generation technology:
1. Solar energy resources are very rich, and the energy radiated to the surface of the earth is huge, which is very beneficial for the use of solar energy. Therefore, solar photovoltaic technology is the most abundant power generation technology.
2. Solar photovoltaic power generation is safer and more reliable, does not cause pollution and noise, and can be flexible and safe and stable.
3. The application of photovoltaic power generation can effectively solve the problem of power consumption in remote areas and special areas, and can use solar energy resources anytime and anywhere.
4. Photovoltaic power generation can be combined with buildings to form a photovoltaic building integrated system, reducing waste of land resources.
Second, history and current situation
The history of solar photovoltaic power generation dates back to 1839 when the French physicist Becquerel first discovered the photovoltaic effect. Since then, scientists from all over the world have continued to explore. The first practical photovoltaic cell was introduced in 1954, which means that solar photovoltaic power generation has gradually entered the road of industrialization.
In the 21st century, solar cells have expanded globally and become an important renewable energy source. With the concept of sustainable development in the world, the scale of global solar energy development and utilization is rapidly expanding, the technology is continuously improving, the cost is significantly reduced, and it has a good development prospect. Many countries regard solar energy as an important emerging industry, and solar energy is more widely used. application. Between 2000 and 2016, the photovoltaic industry moved forward at an amazing rate. The cumulative installed capacity in the world has increased from 1,250 MW to 304,300 MW, with a compound annual growth rate of 40.98%.
Third, the development trend
1. Policy changes
On May 30, 2019, the National Energy Administration issued the "Notice on the Relevant Matters Concerning the Construction of Wind Power and Photovoltaic Power Generation Projects in 2019", clarifying the priority of promoting the construction of unfunded affordable online projects, and then carrying out the competition allocation work requiring state subsidy projects. This will be a major shift for the power photovoltaic industry.
In recent years, Southeast Asian countries have also made corresponding efforts in the field of renewable energy. The scale of photovoltaics in Thailand and Indonesia has increased, while Vietnam is planning to build wind power projects and issue decisions on the development of incentive mechanisms for solar power projects. The Southeast Asian government subsidizes photovoltaic projects, encourages the use of renewable energy, and is close to China due to its geographical proximity.
The expansion of emerging markets and the competition for parity online will become a new trend in the future.
2. Technological development
(1). From distributed generation to construction of centralized power plants
The centralized large-scale grid-connected photovoltaic power station is to concentrate on the construction of large-scale photovoltaic power plants. The power generation is directly integrated into the public power grid, and the high-voltage transmission system is connected to supply long-distance loads, which can reduce costs and reduce transportation losses. The larger the photovoltaic power station, the lower the cost of its photovoltaic system.
(2). Optical storage integrated power station
The photovoltaic power plant with energy storage link is integrated and controlled by optical storage, and it is quickly controlled to meet the maximum output of active power. The “peak cutting and valley filling” responds to the grid dispatching demand and guarantees the grid dispatching requirements in real time. The use of energy storage systems can alleviate the impact on the grid during charging and maximize the quality of the grid.
(3). Application of technologies such as cloud storage, cloud computing, digital hygiene, and big data
The use of new information technology can help photovoltaic power plants to achieve intelligence, help photovoltaic power plants to achieve intelligent operation and maintenance monitoring, provide power generation forecasting and other analysis functions, reduce the difficulty of grid connection, and improve power generation efficiency.
The fourth industrial revolution will be fully launched, and technologies such as clean energy and Internet of Things, which are mainly photovoltaics, are developing in an all-round way. Through modern Internet of Things technology, artificial intelligence and big data analysis technology, we can realize centralized operation and maintenance management of various energy sources including photovoltaics, and create a smart energy ecosystem. In the future, society will build a new energy IoT system into a low-carbon and even carbon-free era.