Distributed photovoltaic power generation is a new and promising way of power generation and integrated energy utilization. It advocates the principles of local power generation, local grid connection, local conversion, and local use. It not only effectively increases the power generation of photovoltaic power stations of the same scale, but also effectively solves the problem of power loss during voltage boosting and long-distance transportation. The basic equipment of the distributed photovoltaic power generation system includes photovoltaic cell components, photovoltaic array supports, DC combining boxes, DC distribution cabinets, grid-connected inverters, AC distribution cabinets, as well as power supply system monitoring devices and environmental monitoring devices. Its operating mode is that under the condition of solar radiation, the solar cell module array of the distributed photovoltaic power generation system converts solar energy into output electrical energy, which is then concentrated through the DC combining box into a DC distribution cabinet. The grid-connected inverter converts it into AC power to supply the building's own load. The excess or insufficient power is adjusted through the connected power grid.
Technical Features
Distributed photovoltaic power generation has the following characteristics:
Firstly, its output power is relatively small. Generally, the capacity of a distributed photovoltaic power generation project is within a few kilowatts. Unlike centralized power stations, the size of a photovoltaic power station has little impact on its power generation efficiency, thus its economic impact is also minimal. The investment return of a small-scale photovoltaic system is not lower than that of a large one.
Secondly, it has low pollution and outstanding environmental benefits. During the power generation process of distributed photovoltaic power generation projects, there is no noise, and it does not produce pollution to the air and water.
Thirdly, it can alleviate local power shortages to some extent. However, the energy density of distributed photovoltaic power generation is relatively low, with a power of about 100 watts per square meter for the distributed photovoltaic power generation system. Additionally, the area of building rooftops suitable for installing photovoltaic components is limited, so it cannot fundamentally solve the problem of power shortages.
Fourthly, power generation and consumption can coexist. Large ground-based power stations generate electricity by boosting it to connect to the transmission grid and operate solely as power generation stations. However, distributed photovoltaic power generation is connected to the distribution grid, allowing power generation and consumption to coexist, with a requirement to consume as much as possible locally.
Technical Advantages:
(1) Small Output Power
Generally, the capacity of a distributed photovoltaic power generation project is within a few kilowatts. Unlike centralized power stations, the size of a photovoltaic power station has minimal impact on its power generation efficiency, thus its economic impact is also minimal. The investment return of a small-scale photovoltaic system is not lower than that of a large one.
(2) Low Pollution and Outstanding Environmental Benefits
During the power generation process of distributed photovoltaic power generation projects, there is no noise, and it does not produce pollution to the air and water.
(3) Alleviating Local Electricity Shortages to Some Degree
However, the energy density of distributed photovoltaic power generation is relatively low, with a power of about 100 watts per square meter for the distributed photovoltaic power generation system. Additionally, the area of building rooftops suitable for installing photovoltaic components is limited, so it cannot fundamentally solve the problem of power shortages. Despite these limitations, distributed photovoltaic power generation can still contribute to reducing local electricity demand pressure.
Solutions
Application Scenarios
The application scope of distributed photovoltaic power generation systems: They can be built in rural, pastoral, and mountainous areas, as well as in developing large, medium, and small cities or commercial areas to meet the electricity demand of local users.
Introduction
Distributed photovoltaic power generation systems, also known as decentralized generation or distributed energy supply, refer to small photovoltaic power supply systems configured on-site or near the electricity consumption site to meet the specific needs of users, support the economic operation of the existing power distribution network, or meet both requirements simultaneously.
The basic equipment of distributed photovoltaic power generation systems includes photovoltaic cell components, photovoltaic array racks, DC combiner boxes, DC distribution cabinets, grid-connected inverters, AC distribution cabinets, as well as monitoring devices for power supply systems and the environment. Its operating mode is that under conditions of solar radiation, the solar cell module array of the photovoltaic power generation system converts solar energy into electrical energy. The electrical energy is sent to the DC distribution cabinet through the DC combiner box. The grid-connected inverter converts it into AC power to supply the building's own load. Excess or insufficient electricity is adjusted through the connected power grid.
Solution Features
The systems are independent and can be controlled individually, avoiding large-scale power outages and ensuring high safety.
They make up for the stability shortcomings of large power grids, continue to supply power during accidents, and become an indispensable supplement to centralized power supply.
They can monitor the quality and performance of regional electricity in real time, which is particularly suitable for supplying electricity to residents in rural, pastoral, and mountainous areas, as well as developing large, medium, and small cities or commercial areas. This greatly reduces environmental pressure.
They have low or even no transmission and distribution losses, and require no substation construction, reducing or avoiding additional transmission and distribution costs, as well as low civil engineering and installation costs.
They have good peak shaving performance and simple operation.
With few systems involved in operation, they start and stop quickly, facilitating full automation.
