1. Battery energy storage status
Wind energy and solar energy are the absolute main forces of new energy power generation, but they are characterized by large fluctuations and difficult to predict, while battery energy storage has the characteristics of fast dispatch response, flexible configuration, precise control and environmental friendliness. It has become the best partner of new energy power generation, which has been the consensus of the industry and has been recognized by relevant national departments.
Although gas-fired power generation and pumped storage power stations can also complete part of the new energy peak regulation work, the smooth output and frequency modulation effects are far less than battery energy storage. Although wind power and photovoltaic power generation concentrated in the same place can naturally balance part of the output fluctuations (such as the wind-solar complementary effect), there will be times when there is no wind and no light. Therefore, supporting a battery energy storage power station of a certain scale is the ultimate choice for new energy power stations to achieve the tracking plan of power generation.
The best energy storage power stations supporting new energy generation have various forms of existence, such as integrated optical storage, wind storage and landscape storage. From the comprehensive consideration of use effect, utilization efficiency, convenient scheduling and business model, independent energy storage power stations with a scale of more than 100 megawatts will occupy the mainstream position.
2. Value of battery energy storage
Battery commercial energy storage has both economic value and social value (all kinds of values besides economic value). From some perspectives, its social value far exceeds its economic value, such as its military value, power security value, energy strategic value, etc. In terms of economic value, it mainly depends on its scale and use occasion. For example, the power bank can only solve the mobile use problem of one or two mobile phone users in a day. Household energy storage or backup emergency energy storage power supply can only solve part of the electricity or temporary power outage problem of a household; User-side energy storage usually only considers peak-valley filling and demand-side response using peak-valley price difference.
Several of the applications listed above have long or no economic payback periods, or even some investment risk. In contrast, due to its fast response speed, accurate control and bidirectional regulation, large-scale energy storage has great social value and rich returns (mainly frequency modulation service fee, capacity service fee, etc.) if it can be used by power grid dispatching in the field of power grid security strategy such as frequency modulation and peak regulation. However, the premise is that there should be an open power market (including power auxiliary service market).
3. The main battlefield of future battery energy storage
Although energy storage technology will be used in new energy microgrids, distributed photovoltaic power generation and user-side peaking (peaking and valley filling), large-scale applications of battery commercial energy storage will be grid side transmission and distribution. Independent battery energy storage power stations with a scale of more than 100 megawatts that can be directly dispatched by the power grid can not only ensure the power supply safety of the power grid, but also improve the power quality of local areas. Battery energy storage will even subvert the traditional design concepts and rules of the power grid, improve the utilization rate of equipment, reduce resource waste, and delay the construction cycle of capacity expansion. With the gradual opening of the power market in the future, the power spot trading and the power auxiliary service market will certainly give birth to a large number of energy storage power stations.
From the point of view of initial investment cost, lithium-ion batteries have strong competitiveness, sodium-sulfur batteries and all-vanadium flow batteries have not formed industrialization, limited supply channels, relatively expensive. In terms of operating and maintenance costs, sodium sulfur requires continuous heating and all-vanadium flow batteries require pumps for fluid control, increasing operating costs, while lithium batteries require little maintenance. According to the application status and battery characteristics of the best energy storage power station at home and abroad, it is suggested that the battery selection of energy storage power station is mainly lithium iron phosphate battery. The reason why it is not recommended to use lead-acid batteries is the battery life. The life of big brand lead-acid batteries is only about 2.5-3 years under frequent charge and discharge. The life of lithium batteries is much longer.