With the acceleration of global energy transition, the proportion of renewable energy is increasing day by day. The intermittency and instability of large-scale renewable energy such as wind power and photovoltaics have caused a huge impact on the safe and stable operation of the power system. In order to address these challenges, energy storage technology and virtual power plants have become research hotspots in the field of how to absorb a wide range of clean energy.

What is a virtual power plant - Aggregation and optimization of distributed resources
The concept of virtual power plants was first based on Dr. Shimon Awerbuch's definition of "virtual public facilities" in his 1997 book "Virtual Public Facilities: Description, Technology, and Competitiveness of Emerging Industries". It refers to flexible cooperation between independent and market-oriented entities, where participating entities can provide consumers with the necessary services without owning corresponding assets. Virtual power plants are an extension of this concept.

Simply put, a virtual power plant is a virtualized power plant, which is a smart grid technology that applies distributed power management systems to participate in grid operation and scheduling, integrating and regulating dispersed elements such as sources, grids, loads, and storage. It can not only systematically consume electricity from the power system, but also output electricity in reverse to the power system, enabling more flexible and efficient operations such as peak shaving and valley filling, and obtaining considerable economic benefits.

Energy storage system - the source of power reserve for virtual power plants
Since the development of virtual power plants, although they have matured in developed countries in Europe and America, forming some small-scale demonstration projects that can be used for reference, they are still mainly pilot demonstrations in China. This is mainly because the potential for source side regulation has entered a bottleneck period, and the key to improving flexibility through virtual power plant technology cannot be separated from mature power reserve facilities.

To address this issue, it is usually considered to solve it through the application of rotating backup, flexible loads, and energy storage. The electric energy from rotating backup and flexible loads is difficult to meet the long-term and large-scale energy storage needs. Therefore, the industry has reached a consensus that the maturity of energy storage technology will be a key node in the transformation of the power system, forming an integrated "source grid load storage" system, in order to build a "multi energy complementary, multi state fusion, and multi interaction" power system.

Therefore, "virtual power plants+energy storage systems" as an innovative technological path provide new solutions to address the challenges brought by large-scale renewable energy grid integration:

Firstly, by introducing energy storage systems, the intermittency and volatility of renewable energy sources such as photovoltaics and wind power can be smoothed out, and the grid connected operation capability of renewable energy generation can be improved. This helps to expand the proportion of wind and solar power generation in the energy structure, while addressing the power security issues brought about by the integration of new energy into the grid;

Virtual power plants can improve power quality through energy storage systems. Although distributed energy in virtual power plants has the advantages of energy conservation and environmental protection, widespread deployment may introduce a large number of harmonics, posing challenges to the stability and efficiency of the power grid. The inverter in the energy storage system can be equipped with active filtering function to counteract the reverse current of harmonic current. This compensation operation helps to reduce harmonic interference and improve the power quality of the virtual power plant;

Energy storage also plays a role in balancing system frequency and ensuring stable operation in virtual power plants. When the supply and load demand on the power generation side are unbalanced, the system frequency will deviate. With the help of energy storage systems, energy can be stored when the system frequency is low and released when the system frequency is high, balancing this frequency deviation and ensuring stable system operation;

Virtual power plants can use energy storage systems to reduce operating costs. For example, when the load demand is small, the system frequency increases, and the frequency deviation is positive during system operation, energy storage devices can be used to ensure system power balance, reduce deviation, and save energy.

With the rapid development of energy transformation and new power systems, new energy storage is an important resource for virtual power plants, which can effectively reduce the load peak valley difference, improve equipment utilization, and reduce costs. Through energy storage technology, virtual power plants can better solve the intermittency problem of renewable energy. With the further development of technology, the communication and interaction of "source grid load storage" has gradually become normalized, and "virtual power plant+energy storage system" will also become an important technical path to explore and solve the problem of electricity demand side response.