Qinghai Province is sparsely populated, and farmers and herdsmen living in many remote areas are scattered and the grid cannot be extended. The province currently has 29 villages without electricity, 626 villages without electricity, and 80,700 households without electricity. In order to solve the problem of power consumption in remote and unpowered areas, Qinghai provincial governments at all levels and the power, science and technology commissions, and water conservancy departments have made unremitting efforts to solve the extension of the power grid, and to extend the power grid as far as possible; if the power grid cannot be extended, According to the local resources, water power, wind power, solar photovoltaic power supply and other methods were adopted.
1 Comparison of several power supply methods
In the above several power supply methods, the construction of small hydropower must have hydraulic resources and a suitable construction address. The key is that it is seasonally strong and cannot generate electricity during the cold season. This problem is particularly prominent in an alpine region like Qinghai.
From the perspective of the use of wind power generation in recent years, due to unstable wind speed, mechanical wear, and maintenance work, it has not fully achieved the expected results. As a result, fewer users have used wind power in recent years.
For solar energy power supply, it is generally welcomed by farmers and herdsmen because it has less mechanical parts, relatively stable operation, simple operation, and small maintenance workload, especially small power supplies are more suitable for mobile grazing.
2 The advantages of solar photovoltaic power
Qinghai Province is located in the Qinghai-Tibet Plateau, where the air is thin, dry and rainless, long sunshine hours, and abundant solar energy resources. The annual sunshine duration in the province is 2328～3575h. The annual solar radiation amount is 584.9～741.4kJ/cm2. More than 80% of the area is a solar energy resource type area, and the rest belongs to the second type area. Solar energy resources are second only to Tibet and are high in the country. Area. Because solar energy resources are clean and renewable energy sources, solar photovoltaic power sources have no pollution. Therefore, compared with other energy sources, using solar energy to solve the problem of electricity consumption for farmers and herdsmen in the remote areas of our province has unique advantages.
3 Introduction to Solar Photovoltaic System
The basic principle of solar photovoltaic power supply is to use solar photovoltaic panels (abbreviated as photovoltaic panels) to convert solar energy into direct current power. The higher the conversion efficiency of photovoltaic panels and the greater the solar radiation energy, the more energy it converts. The solar photovoltaic system is divided into AC and DC power supply modes. The AC power supply system consists of a photovoltaic panel, a battery, a controller, an inverter, a distribution line, and a load. The DC output from the photovoltaic panel is stored in the battery and passed through the inverter. It is converted to 220V, 50Hz and has a sinusoidal type of alternating current for users to use. The difference between DC power supply and AC power supply is that the DC system directly supplies power without inversion. The basic principle of AC power supply system is shown in Figure 1.
Figure 1 AC power supply system of solar photovoltaic power supply
Photovoltaic power supply is divided into two forms: centralized power supply of the power station and distributed power supply of the household power supply. For areas where the population is relatively concentrated, the power station is used for centralized power supply. For users who are dispersed and have high mobility, users are supplied with power.
Whether centralized or decentralized, the power supply capacity is based on the load.
4 Promotion and Use of Solar Photovoltaic Power in Recent Years
In 2003, the province implemented a power transmission project to rural areas. It plans to build 112 photovoltaic power stations in Yushu, Guoluo and Huangnan, with a total installed capacity of 3943kW. The capacity of each power station is between 10 and 50kW. The current project is in the process of implementation. . After the completion of the power station, the power supply is more than 5 hours a day, which can basically solve the problem of electricity consumption in daily life such as lighting and watching TV.
In recent years, the number of household solar energy sources promoted has been between 4 and 300W, of which 4W only has one lamp, 8 to 20W can have 2 to 3 lamps and one recorder, and 50W or more systems can be used to watch TV and lighting at the same time. Electricity problem. The user can choose according to economic affordability and load conditions.
5 Reflections on the Operation and Management of Solar Photovoltaic Power Plants
Since solar power plants are generally located remotely and operate in isolation, to prevent reconstruction of light pipes and equipment from being used improperly, damages should be given to their operation and management. It is recommended that the local government designate a full-time department to directly govern the operation. The on-duty personnel can be selected by the local government. After passing the training, they are required to go on duty. The competent department regularly organizes inspections and guidance and concentrates on major repairs.
Another major issue in ensuring the safe operation of solar power plants is the issue of operating and maintenance costs. The operation and maintenance costs of solar power plants are mainly the replacement of the battery during the operation period and the salaries of the operating personnel. From the current situation, if the electricity revenue of the power supply area alone is not enough, it is necessary to establish a corresponding fund subsidy mechanism. The unified management and use of government departments can guarantee the normal operation of the power station.