The relationship between energy storage and photovoltaics is mainly reflected in the following aspects:
1. Complementarity
As an intermittent energy source, photovoltaic power generation is affected by many natural factors such as sunshine time and solar radiation intensity, showing significant intermittency and volatility. When the sun is sufficient during the day, the power generation of photovoltaic power stations is high; but at night or on rainy days, the power generation will drop sharply or even stop.
Energy storage technology refers to the technology of converting excess energy into other forms of energy and storing it, and releasing it when needed. This characteristic enables energy storage technology to well compensate for the intermittent and instability of photovoltaic power generation and improve the stability and reliability of the power system.
2. Technology combination
Combining energy storage technology with photovoltaic power generation to form an integrated photovoltaic storage system can bring many advantages. For example, through the charging and discharging operation of the energy storage system, the output fluctuation of photovoltaic power generation can be effectively smoothed and the stability of the power grid can be improved.
In practical applications, cases such as residential rooftop photovoltaic energy storage systems, large-scale ground power station supporting energy storage facilities, and microgrid applications have fully demonstrated the advantages of the integrated photovoltaic storage system. This system can not only achieve self-sufficient power supply and reduce electricity bills, but also sell excess electricity to the power grid for profit.
3. Matching of energy storage type and photovoltaic capacity
The selection of energy storage technology needs to be determined according to the specific situation of the photovoltaic power generation system. At present, energy storage technologies mainly include physical energy storage, chemical energy storage and other energy storage methods. Physical energy storage such as pumped storage and compressed air energy storage have been widely used in large photovoltaic power stations; chemical energy storage is mainly battery energy storage, especially lithium-ion battery energy storage system, which has been widely used in residential rooftop photovoltaic energy storage system, microgrid and other fields.
The determination of energy storage capacity needs to consider factors such as the scale of the photovoltaic power generation system, system load demand, discharge time of the energy storage system and economy. Reasonable energy storage capacity and energy storage ratio can improve the overall performance and economy of the photovoltaic power generation system.
4. Development Trends
With the continuous increase in scientific research efforts and continuous technological innovation, energy storage technology is developing towards higher energy density, longer cycle life and lower cost. In the future, energy storage technology will be more widely used in the photovoltaic field, providing a more effective means to solve the intermittent and volatile problems of renewable energy.