Photovoltaic power station refers to a photovoltaic power generation system that uses solar energy and special materials such as crystalline silicon panels, inverters and other electronic components to form a power generation system that is connected to the power grid and transmits electricity to the power grid. Photovoltaic power stations are the green power development energy projects that the country encourages the most.
Photovoltaic power stations have the advantages of promoting the development of "dual carbon" goals, accelerating the transformation of the power system, optimizing the energy structure, enhancing the grid regulation capacity, and promoting technological innovation in helping to build a new power system.
Photovoltaic power generation generally includes centralized photovoltaics and distributed photovoltaics:
① Centralized photovoltaics: Large photovoltaic power stations built using abundant solar energy resources in open areas, converting direct current into alternating current through grid-connected inverters, and connecting to high-voltage transmission systems to supply long-distance loads. It has the characteristics of large investment scale, long construction period, and large land area.
② Distributed photovoltaics: A power supply system located near the user's location, usually composed of photovoltaic modules, junction boxes and inverters, etc., mainly built on the roofs of factories, office buildings and residential buildings. The electricity produced is consumed in the form of "self-generation and self-use, surplus power to the grid" or "full grid access". It has the advantages of small footprint, low dependence on power grid, flexible and intelligent.
What is a centralized photovoltaic power station?
A centralized large-scale grid-connected photovoltaic power station refers to a large-scale photovoltaic power station that is built in areas with large areas of unused land such as deserts, Gobi, water, deserts, mountainous areas, and relatively stable solar energy resources. The power generation is directly connected to the public power grid and connected to the high-voltage transmission system. The power grid is uniformly allocated to supply power to users. The grid-connected voltage is generally 35 kV or 110 kV.
The land nature requirements for centralized photovoltaic power stations are relatively high. At present, common centralized power stations usually use deserts, mineral wastelands, Gobi, saline-alkali land, wasteland, tidal flats, etc. The investment cost of the power station is high, the construction period is long, and the area is large.
Centralized photovoltaic power stations are divided into three categories according to installed capacity: large, medium, and small. Large usually refers to more than 500 megawatts and above, medium is generally 50-500 megawatts, and small is generally less than 50 megawatts.
Advantages of centralized photovoltaic power stations:
1. More flexible site selection and operation mode, 2. Low operating cost, easy to centrally manage 3. Increased stability of photovoltaic output, and full use of the positive peak-shaving characteristics of solar radiation and power load to play a role in peak reduction.
What is a distributed photovoltaic power station?
A distributed photovoltaic system refers to a photovoltaic power generation facility built near the user's site, with the main operation mode being self-generation and self-use on the user side, and the surplus power being connected to the grid, and the distribution system being balanced and regulated.
Distributed photovoltaic power generation systems advocate nearby power generation, nearby grid connection, nearby conversion, and nearby use, which effectively solves the problem of power loss during voltage boosting and long-distance transmission. It is a new type of power generation and comprehensive energy utilization method with broad development prospects.
Distributed photovoltaics can be divided into two modes according to the consumption mode: "full grid access" and "self-generation and self-use, surplus power connected to the grid".
Full grid access means that all the power generated by the photovoltaic power generation system is connected to the grid.
Self-generation and self-use, surplus power to the grid refers to the electricity generated by the photovoltaic power generation system, which is used by power users first, and the surplus power is connected to the grid;
Common distributed photovoltaic power stations include: industrial and commercial rooftop photovoltaic, fishery-photovoltaic complementarity, agricultural-photovoltaic complementarity, forest-photovoltaic complementarity, photovoltaic building integration and other types of photovoltaic power stations.
Characteristics of distributed photovoltaic:
Feature 1: Located near the user Feature 2: Access at 10 kV and below Feature 3: Access to the distribution network and local consumption Feature 4: Single-point capacity does not exceed 6 MW (multiple-point access is subject to the maximum)
What are fishery-photovoltaic complementarity, agricultural-photovoltaic complementarity, and forest-photovoltaic complementarity photovoltaic power stations?
Agricultural-photovoltaic complementarity, fishery-photovoltaic complementarity, and forest-photovoltaic complementarity are new models for photovoltaic power station construction and belong to photovoltaic composite projects.
Its characteristics are that it does not occupy land, does not change the surface morphology, does not damage the nature of agricultural land, and does not hinder agricultural and forestry production activities such as greenhouse planting, fish pond breeding and vegetation growth.
Among them, agricultural-photovoltaic complementarity is a technology that combines photovoltaic power generation and agricultural planting. The advantages are pollution-free, zero emission, and no additional land occupation, which can realize three-dimensional value-added utilization of land. The agricultural photovoltaic complementary model is photovoltaic power generation outside the shed and vegetable planting inside the shed. In addition to the use of electricity in the shed, the remaining electricity is incorporated into the public power grid.
Fishery photovoltaic complementary uses the vast area of the fish pond to install a solar power generation system above the water surface of the fish pond, and aquaculture is still carried out below. The profit is greatly increased compared with simple aquaculture. It is generally built in lakes, rivers, ponds, streams, rice fields and other areas.
Forest photovoltaic complementary refers to a power station model that combines photovoltaic power generation with forest land. Make full use of forest resources, use photovoltaic brackets to mount photovoltaic modules at a height of more than 2 meters above the ground, reserve enough space under the photovoltaic modules, vigorously develop economic shrub planting, and organically combine photovoltaic power generation with forestry development to achieve three-dimensional value-added utilization of land.
What is a BIPV photovoltaic power station?
BIPV refers to photovoltaic building integration, which is a solar photovoltaic power generation system that is designed, constructed and installed at the same time as the building, and forms a perfect combination with the building. It is also called "construction-type" and "building material-type" solar photovoltaic buildings.
As an integral part of a building, BIPV can be used as a substitute for roofs, skylights, building facades, etc.
After replacement, it has both power generation functions and the functions of building components and building materials. It can even enhance the beauty of the building and form a perfect unity with the building.
The application forms of BIPV mainly include: roof integration, photovoltaic vertical curtain walls, photovoltaic glass windows, photovoltaic shading eaves, etc. The life cycle of the BIPV system is generally more than 25 years.
Photovoltaic roofs have high power generation efficiency and are currently the main application scenario of BIPV. From the perspective of power generation, photovoltaic roofs and photovoltaic skylights used on building roofs can obtain the longest lighting time and a larger lighting area, with the best economic benefits. Among them, flat roofs can obtain the maximum power generation because the photovoltaic system can be installed at the best sunshine angle.
What is a BAPV photovoltaic power station?
BAPV is a form of photovoltaic building integration. It refers to a solar photovoltaic power generation system attached to a building, also known as an "installed" solar photovoltaic building.
BAPV is only a photovoltaic material attached to a building. It does not assume the function of the building, does not conflict with the function of the building, and does not damage or weaken the function of the original building.
The main function of BAPV is to generate electricity. The advantages are simple construction, low cost and convenient installation.
BAPV is generally used in existing buildings and installed on the surface of buildings with good lighting. The main implementation forms include: roof tilt type, roof flat type, wall adsorption installation, etc.
It should be noted that BAPV is to install a photovoltaic system on an existing building. Therefore, the BAPV photovoltaic system will increase the building load, so a professional company is needed to design and construct it to ensure the safety of the building and the stability of the photovoltaic system.