Solar energy, as a kind of clean and renewable energy, has been more and more widely concerned and applied in today's world. However, the intermittency of solar energy storage systems has always been an important factor restricting their development.
 
The nature of the problem in intermittent solar energy storage systems
The intermittency problem in solar energy storage systems mainly arises from the instability and unpredictability of solar energy.  The generation of solar energy is influenced by many factors, such as weather, season, and time, which makes its output power fluctuate greatly. Besides, energy storage devices like batteries in solar storage systems also have certain limits in terms of charging and discharging efficiency and life, which further aggravates the intermittency problem.
Specifically, the intermittency problem of solar energy storage systems is mainly reflected in the following aspects:
Power fluctuation: The output power of solar energy will fluctuate greatly with the change of weather, season, time, and other factors, which makes the output power of solar energy storage system unstable, and it's difficult to meet the stable demand for electricity from users.
Insufficient energy could be related to the inability of the solar energy storage system, especially on cloudy days and nights when there is not enough solar energy or even night times.
Service life of the battery applied: A battery in every Solar storage system has a few limited charges and discharging, with some efficiency also for service; prolonged-time working may cause lower performance in energy storage which means its reliabilities and stability will lose seriously;
 
Solution for the intermittent issue of the solar energy storing system:
The following aspects can be starting points for solving the intermittence problem of a solar energy storage system:

Improve the accuracy of solar energy forecast
Forecast of solar energy using weather data and artificial intelligence algorithms.  Establishment of a solar energy prediction model, based on the collection of meteorological data of the place like solar radiation intensity, temperature, humidity, and cloud cover among others.
Artificial intelligence algorithms, such as neural networks and support vector machines, are used for training and optimization to further enhance the accuracy of the solar energy prediction model.  Installation of Solar Monitoring Equipment Solar monitoring equipment is installed within the solar power generation system that is responsible for monitoring solar power output and weather conditions in real-time.
Through the analysis of monitoring data, the operating state can be regulated in time to enhance the efficiency and stability of the solar power system.
 
(2) Optimization design of solar energy storage systems
Choose the right type of energy storage device
According to the user's power needs and the output power of the solar power generation system, the appropriate energy storage equipment is selected, such as lithium-ion batteries, lead-acid batteries, flow batteries, etc.
In terms of charging and discharging efficiency, life, cost, and other factors of energy storage equipment, cost-effective energy storage equipment should be selected.
Hybrid energy storage system:
A hybrid energy storage system consists of different kinds of energy storage devices, such as lithium-ion batteries and supercapacitors. The hybrid energy storage system can give full play to the advantages of different energy storage devices, improve the energy storage capacity and power output capacity of the system, and reduce the cost and volume of the system.
 
Optimize the control strategy of the energy storage system
Advanced energy storage system control strategies, such as power balance control and energy management control, are adopted to optimize the control of the energy storage system.
It adjusts the charge and discharge power of the energy storage system in real-time and coordinates the operation of the solar power system and the energy storage system to improve the efficiency and stability of the system.The coordinated control strategy for solar power generation system and energy storage system is developed.
 
(3) Developing Smart Grid Technology
Microgrid technology
A microgrid system connecting the solar power generation system, energy storage system, and user load forms an independent power system.
It optimizes the management of the solar power generation system and energy storage system, improving the reliability and stability of the system to reduce users' electricity costs.
Smart Grid Communication Technology
Smart grid communication technology is used for information interaction and coordinated control among the solar power generation system, energy storage system, and power grid.
Real-time monitoring and analysis of the power grid will help timely adjustment in operation state both for solar power generation system and energy storage system to achieve efficient use of solar energy and assure stability of the power grid.
 
(4) Policy support and market mechanisms
Formulate relevant policies
The government can formulate relevant policies to encourage enterprises and individuals to invest in the construction of solar power generation systems and energy storage systems, including but not limited to providing subsidies and tax incentives.
Meanwhile, it can also strengthen supervision over the safe and reliable operation of solar power generation systems and energy storage systems.
 
Establish Market Mechanism
Establish a sound market mechanism to promote the market-oriented development of solar power generation systems and energy storage systems, such as the establishment of power trading markets, energy storage service markets, etc.
Through the role of market mechanism, the optimal configuration and efficient utilization of solar power generation system and energy storage system are realized, and the economic and social benefits of the system are improved.

It is obvious that the intermittency problem in the solar energy storage system restricts the development of solar energy, but this issue could be effectively solved by increasing the precision in forecasting the solar energy, optimizing the design and improvement of the solar energy storage system, technology in smart grid, policy support, and market mechanism.With the continuous progress of technology and the continuous improvement of policies, the intermittency problem of solar energy storage systems will be gradually solved, and solar energy will become an important part of the future energy system.