Photovoltaic (PV) energy storage systems are a reliable means of efficiently utilizing clean energy and have become the preferred energy method in many countries and regions. With the further expansion of installed PV capacity, PV energy storage systems are also known as the new normal.
Concepts
What is energy storage? Energy storage mainly refers to the storage of electrical energy. Energy storage is not an emerging technology per se, but it is new and in its infancy from an industrial point of view.
What is Photovoltaic?
Photovoltaic (Photovoltaic): solar photovoltaic power generation system (Solar powersystem), is a use of solar cell semiconductor materials of the photovoltaic effect, the sun's radiant energy is directly converted to electrical energy, a new type of power generation system, independent operation and grid-connected operation of two ways.
At the same time, solar photovoltaic power generation system classification, a centralized, such as large-scale Northwest ground-based photovoltaic power generation system; a distributed (to > 6MW for the demarcation), such as industrial and commercial enterprises plant roof photovoltaic power generation system, residential roof photovoltaic power generation system.
What is a photovoltaic system?
PV systems can be categorized into grid-connected PV systems and stand-alone PV systems depending on whether they are grid-connected or not.
What is PV+Storage?
The combination of photovoltaic power and battery as an energy storage device is PV+Energy Storage.
Grid-connected photovoltaic energy storage system
Grid-connected photovoltaic power generation system is directly connected to the distribution grid, the power is directly input into the grid, at present, generally do not configure the energy storage system, with the photovoltaic, wind power generation, "abandoned light and limited power" phenomenon is serious, as well as photovoltaic, wind power generation system, the fluctuations in the power output of the larger factors of the utilization of renewable energy and the promotion of the restrictions are becoming increasingly serious after, in the grid-connected The configuration of energy storage in grid-connected photovoltaic system has become one of the research directions of large-scale energy storage system.
Grid-connected photovoltaic power generation system in the configuration of energy storage by the energy storage target decided, energy storage target can be specifically divided into: smooth output, economic scheduling, microgrid composition.
1) Smooth Output
Photovoltaic power generation is the process of converting solar energy into electricity, its output power is affected by the intensity of solar radiation, temperature and other environmental factors and drastic changes, in addition, due to the output of photovoltaic power for the DC current, which needs to be converted into alternating current through the inverter to connect to the power grid, in the process of inversion will produce harmonics. The unstable power of PV power and the existence of harmonics make the access of PV power will cause an impact on the power grid. Therefore, an important purpose of configuring energy storage in grid-connected photovoltaic power generation system is to smooth the output of photovoltaic power and improve the quality of photovoltaic power. To smooth the PV power output as the goal of the energy storage system configuration generally in the PV power generation side of the configuration of centralized energy storage system to smooth the output as the goal of the PV energy storage system structure.
2) Power Peaking
PV power grid, need to accept the grid scheduling, but its power output peak stage and grid load stage is not consistent, coupled with the power market peak and valley tariff factors, the use of energy storage system to realize the PV power generation in the time coordinates of the leveling, so that the PV power to participate in the grid peaking is also one of the hot spots of the current PV energy storage system research. Through power peaking, the access capacity of PV power in the grid and the economy of PV power can be improved.
3) Microgrid Application
Microgrid is a new type of grid structure proposed in order to promote the utilization of renewable energy, specifically the form of a regional-type grid composed of renewable energy, energy storage systems and loads, which, as an independent whole, can be operated either grid-connected or islanded in off-grid state. As a microgrid component unit of the energy storage system is the energy buffer link in the microgrid, the microgrid plays an important role in improving the control stability, enhancing the power quality of the microgrid, maintaining the power balance of the microgrid, and improving the microgrid's ability to resist interference. In addition, the energy storage system in the microgrid can also be used as an emergency backup in case of grid power interruption.
Stand-alone photovoltaic energy storage system
Stand-alone photovoltaic system is relative to the grid-connected photovoltaic system, refers to the independent operation of the photovoltaic system without access to the grid. Currently more widely used stand-alone systems such as solar street lights, solar mobile power, etc., its PV power output and load power consumption is not in the same time period, while the PV power output can not always meet the load requirements, so in the stand-alone photovoltaic power generation system configuration of the total energy storage type to enhance the utilization of photovoltaic power output, enhance the stability of the system, an effective means, while the storage system also has a load for the start-up current, clamping voltage, etc. At the same time, the energy storage system also has the role of providing the load with starting current and clamping voltage.
Currently widely used stand-alone PV systems are generally composed of three parts: PV power generation, control/inverter and energy storage.
Working mode of photovoltaic energy storage system
Photovoltaic power generation has a high level of power in the midday short time, the other hours of power level is low and the daytime power, no power at night, energy storage technology has the ability to realize the characteristics of the time-space shift of electric energy, for photovoltaic power station configuration between the storage of photovoltaic power will be transferred to the other hours of the midday power to abate the power station power spikes, reduce the abandonment of light.
In the battery energy storage system work process, in order to minimize the number of charge and discharge of the energy storage system as a principle, in order to extend the service life of the energy storage system. During the peak hours of PV power generation, the battery storage system is controlled to be charged, and the output of the PV power station is peak shaved. After the peak hours of PV power generation, the battery storage system is controlled to discharge, and the discharge control of the energy storage system can assist in smoothing the volatility of PV power and assisting the system peak shifting to maximize the role of energy storage.
According to the different role of energy storage discharge can be divided into three working modes of the energy storage system, respectively, peak shaving, peak shaving + leveling and peak shaving + transfer question style.
Working Mode 1: Peak Shaving
During the peak output time of the PV power station, control the battery energy storage system charging with peak shaving as the application objective, after the peak output time of the PV power station and during the daytime processing time of the PV, control the power amplification of the battery energy storage system, discharge to the lower limit value of the SOE working range of the battery energy storage system, and then the energy storage system stops working, to ensure that the working time of the energy storage system is in the power generation time of the PV power station, and does not increase the working time of the PV power station, and reduce the impact on the working schedule of the PV power station due to the configuration of the energy storage system. This ensures that the working time of the energy storage system is within the power generation time of the PV power plant, and does not additionally increase the working time of the PV power plant, and reduces the impact on the working arrangement of the PV power plant due to the configuration of the energy storage system.
Working Mode 2: Peak Shaving + Leveling
During the peak hours of PV power plant output, the battery storage system is charged with the application objective of peak shaving.
The output fluctuation of large-scale PV power station can be divided into two categories, one is the slow change of PV power station output, such as the cyclical change of PV power station output caused by the alternation of day and night, and the other is the sudden change of PV power station output, such as the sudden drop of PV power station output caused by the floating cloud blockage.
The first round of changes is large in magnitude but slow in change; the second type of change is unpredictable and sudden, and in severe cases, the output is reduced from full generation to below 30% of the rated value in 1-2 s. After the peak PV output period, the goal is to smooth the downward fluctuation of the PV plant output during the alternation of day and night by controlling the discharge of the storage system, and discharging it to the lower limit of the operating range of the SOE of the battery storage system, and if it has entered the night time, the If the PV power plant output drops to 0, the SOE of the energy storage system is still greater than 0.2, control the energy storage system to discharge at rated power until the SOE drops to 0.2, and then control the energy storage system to stop working.
Work mode three: peak shaving + transfer
In the peak hours of PV power plant output, peak shaving is used as the application objective to control the charging of the battery storage system.
The output time of PV power station is 8:30-18:30, and the evening peak of the load appears between 18:00-22:00, in which the PV power station has basically no output, and the battery storage system can be discharged by controlling the battery storage system to assist the system peak shifting, in order to reduce the number of actions of the energy storage system and simplify the operation of the battery storage system, the battery storage system is controlled to be discharged with constant power, and discharged at the lower limit value of the SOE operating range of the battery storage system, and then the storage system stops working. system SOE operating range lower limit value, and then the energy storage system stops working.
Summary:
Photovoltaic + energy storage system has many advantages, can be realized to a certain extent photovoltaic power generation self-generation and self-consumption, greatly reducing the cost of power generation, electricity; to provide pure electricity, help energy saving and emission reduction; can provide the grid with the corresponding protective function, greatly enhance the flexibility of the use of electric power resources and security and so on.
Photovoltaic industry has always been one of the popular industries in the field of renewable energy. With the continuous progress of technology and market expansion, the photovoltaic industry has ushered in a more and more fruitful moment. In recent years, the development of the photovoltaic industry chain has become more and more perfect, and the rise of energy storage technology has also brought new development opportunities to the photovoltaic industry. The combination of photovoltaic + energy storage has become the industry's hotspot, what impact does this collocation bring to the photovoltaic industry chain?
1.The combination of photovoltaics + energy storage:Promotes high efficiency in energy utilization
The combination of photovoltaic (PV) and energy storage promotes efficient energy utilization. Photovoltaic (PV) power generation is a process that relies on the direct conversion of light energy into electricity, which can achieve sufficient power generation when there is sufficient solar energy, but the capacity of PV power generation decreases or even interrupts at night or in bad weather.
With the addition of energy storage technology, PV power generation can store excess power and release it to supply to users when needed, thus solving the problem of unstable power supply.
Energy storage technology also enables PV power generation systems to better cope with power fluctuations, improving power generation efficiency and increasing system stability and reliability.
2.The combination of photovoltaic + energy storage:Drives the Intelligent Development of Power Systems
The combination of photovoltaic + energy storage promotes the intelligent development of power system. The PV+storage system can realize autonomous deployment of power and intelligent management of energy storage, and optimize the scheduling of energy storage equipment through an intelligent control system, which makes the balance of supply and demand between power generation and power consumption more accurate and flexible.
In this intelligent system, photovoltaic power generation and energy storage technologies are integrated with each other to achieve efficient utilization and delivery of energy by monitoring and predicting real-time power demand, improving the responsiveness of the power system and energy utilization.
The intelligent PV + energy storage system can also effectively interconnect with the power grid, optimize power scheduling, and improve the load capacity and anti-interference capability of the power grid.
3.The combination of photovoltaic + energy storage:Promotes the extension and improvement of the industrial chain
The combination of photovoltaic + energy storage promotes the extension and improvement of the industrial chain. The development of photovoltaic industry includes not only the manufacturing of photovoltaic cells, modules and systems, but also the construction, operation and maintenance of photovoltaic power plants.
The introduction of energy storage technology makes the PV industry chain extend to the R&D, manufacturing and operation of energy storage equipment, providing new opportunities for the comprehensive development of the PV industry chain.
In addition, the combination of PV+energy storage also provides new development direction and market demand for power storage, battery materials, battery recycling and reuse and other related industries.
4.The combination of photovoltaic + energy storage:Promotes the green transformation of the energy industry
The combination of photovoltaic (PV) power generation and energy storage drives the green transformation of the energy industry. Photovoltaic (PV) power generation and energy storage technologies are both important components of the clean energy sector, and their combination not only reduces dependence on traditional fossil energy sources, but also reduces greenhouse gas emissions and realizes sustainable energy development.
The application of photovoltaic + energy storage system can promote the use of green energy in various fields such as ground-based photovoltaic power plants, rooftop photovoltaic power generation systems, rural grid construction, etc., to further increase the proportion of renewable energy sources, and contribute to the decarbonization of the energy industry and the development of environmental protection.
The combination of photovoltaic + energy storage on the photovoltaic industry chain is multifaceted, it promotes the efficient use of energy, promotes the intelligent development of the power system, promotes the extension and improvement of the industrial chain, as well as promoting the green transformation of the energy industry.
The combination of photovoltaic + energy storage has injected new vitality into the renewable energy industry and provided strong support for realizing the goal of clean energy. With the continuous progress of technology and market expansion, it is believed that PV + energy storage will play an increasingly important role in the future development.
Boland Renewable Energy Co.,LTD As an integrated new energy power company, providing you with high quality integrated wind energy , solar energy and energy storage system solutions.Boland is now a subsidiary of CRRC, and is responsible for the overseas expansion of CRRC's wind power & solar power business. We have a relatively complete internal supply chain, service network and excellent product quality and technology.
Boland Обеспечить EPC электростанции, инвестиции и приобретение электростанции.
Пожалуйста, не стесняйтесь обращаться к нам, если вам нужна техническая поддержка. Приветствуем наше сотрудничество!
Моя электронная почта: marketing@boland-hydroturbine.com
Вашингтон: +8613923745989