Previously, there was an article that analyzed that a large number of distributed photovoltaics may bring a series of problems after being connected to the distribution network. One of them is the problem of voltage overrun, that is, the voltage on the low-voltage distribution line is higher than the outlet voltage of the distribution transformer.
And one of the effective means to deal with this problem is to configure energy storage. When the voltage exceeds the limit, the energy storage device is started for charging, which can promote the consumption of photovoltaic power generation. When the electricity load increases, the energy storage can be released to support the electricity demand.
As early as May 2021, the National Energy Administration issued the "Notice on Matters Related to the Development and Construction of Wind Power and Photovoltaic Power Generation in 2021", proposing to encourage qualified household photovoltaic projects to be equipped with energy storage under the premise of ensuring safety.
On June 13, 2023, the National Energy Administration once again issued the "Notice on Printing and Distributing the Pilot Work of Carrying Out the Evaluation of the Carrying Capacity and Improvement Measures of Distributed Photovoltaic Access to the Power Grid", proposing to focus on solving the problems of limited distributed photovoltaic grid connection, actively evaluating the use of new distribution networks, new energy storage, load-side response, virtual power plants and other measures to build a smart distribution network and improve the carrying capacity of distributed photovoltaic access to the grid, and selected 6 pilot provinces, each province selected 5-10 pilot counties (cities) to carry out pilot work.
According to incomplete statistics from Polaris Energy Storage Network, up to now, 9 provinces and 20 places have issued distributed photovoltaic distribution and storage policies, mainly concentrated in Shandong, Jiangsu, Zhejiang, Hebei and other regions with good distributed photovoltaic resources and market development.
Judging from the timing of policy release, the relevant policies are mainly concentrated in 2023. From 2021 to 2023, the number of distributed PV distribution and storage policies will show an upward trend year by year. Since the beginning of this year, a number of provincial documents have clearly put forward the relevant requirements for distributed photovoltaic configuration and energy storage, and the distribution and storage needs have also become more specific.
As proposed in the "Key Points of the Work of the Anhui Provincial Development and Reform Commission in 2024", the distributed photovoltaic distribution and storage project (pilot) will be implemented to expand the installed capacity of new energy storage power stations.
Coincidentally, the Jiangxi Provincial Energy Bureau has issued a notice on further promoting the healthy and orderly development of rooftop distributed photovoltaic power generation projects, encouraging rooftop distributed photovoltaic power generation projects to improve peak regulation capacity through energy storage and other means. In areas where the assessment level of the power grid carrying capacity is yellow or red, the carrying capacity of the power grid can be improved through measures such as the construction of energy storage (including rental, off-site distribution and storage, etc.), and centralized confluence.
From the perspective of the purpose of distributed distribution and storage, there are two main kinds: one is to promote the development of new energy storage in the region, such as Jindong District, Jinhua City, while requiring the construction of energy storage, it also arranges demand response subsidies, project construction subsidies and other policies for energy storage power stations, with the goal of making new energy storage power stations in the region reach a certain scale. Shandong, Henan and other places hope to ensure the access and consumption of distributed photovoltaics by installing energy storage.
From the perspective of policy release areas, they are mainly distributed in major photovoltaic provinces such as Shandong, Zhejiang, Anhui and Henan. Although the scale of a single project of distributed photovoltaic is very small, in some provinces, the proportion of installed capacity is not to be underestimated. According to the data, the cumulative grid-connected capacity of distributed photovoltaics in Shandong and Henan has accounted for nearly 80% of the total installed photovoltaic capacity, and the problem of new energy consumption needs to be solved urgently.
From the perspective of distributed photovoltaic distribution and storage requirements, half of the regions have given specific requirements for distribution and storage, with a distribution and storage ratio of 8%~30% and a duration of 2~4 hours. In addition, some regional policies do not clearly stipulate the proportion and duration of allocation and storage.
In the long run, distributed photovoltaic distribution and storage is an important part of establishing a clean, safe and stable power system, which is conducive to the sustainable development of the new energy power system in mainland China. However, the construction of energy storage will undoubtedly increase the investment cost of photovoltaic project development. In what mode and where is energy storage built? How does energy storage reap the benefits? The unclear business model may be the main reason for the current distribution and storage thunder and rain. Improving the economy of distributed energy storage is an important way to promote the development of distributed photovoltaic energy storage.
It is worth noting that the recent distributed photovoltaic distribution and storage policies in many places have promoted centralized confluence and other modes to achieve capacity increase in station areas and lines, and the power market policies in some regions have begun to make it clear that the photovoltaic system after centralized confluence can be distributed and stored, controllable, adjustable and participate in the market.
In addition, some regions propose shared energy storage and cloud energy storage models, build centralized energy storage, and provide leasing services to distributed photovoltaic users, which may be one of the ways out.
For example, in the "Notice on Further Improving the Grid-connected Operation of Distributed Photovoltaics" in Dezhou, Shandong Province, it is proposed to actively promote the mature implementation path and development mode of "centralized confluence" and "intelligent and transparent regulation", and actively explore innovative models such as "cloud energy storage".
Jiangxi issued the "Notice on Further Promoting the Healthy and Orderly Development of Rooftop Distributed Photovoltaics". According to the document, rooftop distributed photovoltaic power generation projects are encouraged to improve peak regulation capacity through energy storage and other means. In areas where the assessment level of the power grid carrying capacity is yellow or red, the carrying capacity of the power grid can be improved through measures such as the construction of energy storage (including rental, off-site distribution and storage, etc.), and centralized confluence.
The "Interim Measures for the Management of Distributed Photovoltaic Power Generation Projects in Nanning (Draft for Public Comment)" also mentions that the construction model of "centralized confluence + rental energy storage" photovoltaic projects will be actively promoted.
Yangzhou, Jiangsu Province's "Implementation Opinions on Accelerating the Development and Utilization of Photovoltaic Power Generation in the City (Trial)" proposes to encourage the development and construction of a number of centralized energy storage projects in areas where distributed photovoltaic projects are relatively concentrated and the amount of on-grid electricity is large.
