What are the application scope and installation methods of distributed photovoltaic power generation systems?

The applicable occasions of distributed photovoltaic power generation systems can be divided into two categories. They can be promoted on various types of buildings and public facilities across the country, thus forming distributed building photovoltaic power generation systems. Distributed power generation systems can be established using various local public facilities and buildings to meet part of the electricity demand of power users and provide production electricity for high-energy-consuming enterprises. They can be promoted in remote areas such as islands with little or no electricity, thus forming microgrids or off-grid power generation systems. Due to the gap in economic development levels, some people in remote areas of my country still have not solved the problem of basic electricity use. In the past, most rural power grid projects relied on the extension of large power grids, small thermal power, small hydropower, etc. for power supply. The extension of the power grid is extremely difficult, and the power supply radius is too long, resulting in poor power supply quality. The development of off-grid distributed power generation can not only solve the basic electricity use problems of residents in areas without electricity, but also cleanly and efficiently utilize local renewable energy, effectively solving the contradiction between energy and environment. Distributed photovoltaic power generation systems include off-grid, grid-connected, and multi-energy complementary microgrids. Off-grid distributed photovoltaic power generation is mostly used in remote areas and island areas. It is not connected to the large power grid, and uses its own power generation system and energy storage system to directly supply power to the load. Grid-connected distributed power generation systems are generally used near users, and are generally connected to medium and low voltage distribution networks for self-generation and self-use. When power generation is not possible or power is insufficient, electricity is purchased from the grid, and when power is surplus, electricity is sold online. Distributed photovoltaic systems can also form multi-energy complementary micro-electric systems with other power generation methods, such as water, wind, and light, which can be operated independently as a microgrid or connected to the grid for network operation.

Distributed photovoltaic power generation refers to photovoltaic power generation facilities that are built near the user's site and operate mainly for self-generation and self-use by users, with excess electricity connected to the grid, and balanced regulation in the distribution system. Distributed photovoltaic power generation includes grid-connected distributed photovoltaic power generation, off-grid distributed photovoltaic power generation, and multi-energy complementary microgrids. Grid-connected distributed power generation is mostly used near users. It is generally connected to medium and low voltage distribution networks for self-use. When power generation is not possible or power is insufficient, electricity is purchased from the Internet. When power is surplus, electricity is sold to the Internet. Off-grid distributed photovoltaic power generation is mostly used in remote areas and islands in my country. It is not connected to the large power grid and uses its own power generation system and energy storage system to directly supply power to the load. Distributed photovoltaic systems can also be combined with other power generation methods to form complementary micro-power such as water, wind, and light storage complementary power generation systems. They can be operated independently as micro-grids or integrated into the grid for network operation. For photovoltaic systems built on the ground in the western region, power supply to specific users and load balancing through the public power grid can also be regarded as a generalized distributed photovoltaic power generation.

PV building integration proposes a new concept of "self-generation and self-power supply of buildings", that is, the integration of buildings and photovoltaic power generation, and the layout of photovoltaic arrays on the surface of the building's external protective structure to generate electricity. Use photovoltaic devices as building materials. It must meet several conditions required by building materials: durability, thermal insulation, waterproof and moisture-proof, appropriate strength and stiffness and other properties. If it is used for windows, skylights, etc., it must be able to transmit light, that is, it can generate electricity and daylight. In addition, factors such as safety performance, appearance and ease of construction must also be considered. The forms of combining photovoltaics with buildings mainly include combining with roofs, combining with walls, and combining with sunshade devices. Characteristics of building photovoltaic integration. The photovoltaic array of the grid-connected system is installed on the roof or wall of an idle building, without occupying land or adding other infrastructure. It is suitable for densely populated cities, which is especially important for urban buildings with expensive land. The generated energy is fed into the power grid, eliminating batteries, saving construction investment and maintenance costs, thereby greatly reducing the cost of power generation. It improves the system's average time between failures and prevents secondary pollution of batteries. Distributed construction can generate electricity and use electricity on site, minimizing transmission costs and losses. It can save investment in conventional power grids within a certain distance. Local power generation and supply, flexible access to and from the power grid. In summer, due to the use of a large number of refrigeration equipment, a peak in power consumption is formed in the power grid. This is also the time when the photovoltaic array generates the most electricity. In addition to ensuring its own building electricity consumption, the BIPV system can also supply power to the power grid, thereby alleviating peak power demand. Since the photovoltaic array is installed on the external protective structure such as the roof and wall, it absorbs solar energy and converts it into electrical energy, which greatly reduces the outdoor comprehensive temperature, reduces the heat gain of the wall and the indoor air conditioning cooling load, which not only saves energy but also helps to ensure the indoor air quality. Due to the modularization of photovoltaic cell components, the photovoltaic array is easy to install and the power generation capacity can be arbitrarily selected.