In 2019, the development of my country's photovoltaic industry has come to a critical adjustment period. Not only does the development of the entire industry tend to be orderly from "barbaric growth", but the entire industry chain needs to complete an all-round transformation of quality, technology and efficiency. At present, my country's photovoltaic industry has achieved great progress in technology, technology, efficiency and other aspects in recent years, and policies have also begun to focus on reducing the non-technical costs of the industry. It is reasonable to say that the development of the photovoltaic industry should be bright.

But in the long run, as photovoltaic power generation gets closer to grid parity, and as photovoltaic power generation becomes more and more deeply embedded in the national power market, there is a problem that will increasingly become a bottleneck for the development of photovoltaic power generation.

Photovoltaic power generation faces bottlenecks

According to data released by the National Energy Administration, the national photovoltaic power generation in 2018 was 177.5 billion kWh, a year-on-year increase of 50%. In the future, as photovoltaic power generation achieves grid parity, the scale and power generation of photovoltaics will further explode and begin to gradually replace traditional energy sources.

It can be said that with the advent of the era of grid parity, photovoltaic power generation will face the competition of traditional coal power. In addition to price and cost, photovoltaic power generation has a huge disadvantage compared to traditional coal power, that is, stability. Since the intensity of sunlight is changing at any time, the voltage and current output of photovoltaic power stations are fluctuating. Even with the modulation of photovoltaic inverters, this fluctuation can only be smoothed out as much as possible, but cannot be eliminated. The most important thing is that in the dark night without the sun, the photovoltaic power station cannot generate electricity at all, and this instability will make the power grid connected to the power station suffer greatly.

At present, with the continuous development of photovoltaic technology, the cost of photovoltaic power generation is lower than that of traditional coal power is just around the corner. In this way, stability may become the primary factor that undermines the competitiveness of photovoltaic power generation.

However, as far as the mode of photovoltaic power generation is concerned, there is basically no way to solve its instability through ordinary photovoltaic systems. What can solve the stability of photovoltaic power generation is energy storage.

Energy storage is the key to breaking the game

In fact, the use of energy storage to solve the instability problem of photovoltaic power generation has long been reflected. In order to solve the fluctuation caused by a large number of photovoltaic power generation, the power grid generally needs to use the energy storage system to cut peaks and fill valleys, so as to achieve the purpose of stabilizing the large power grid system. This is the help that energy storage provides to photovoltaic power generation on the grid side, and this is only one aspect of it.

In the off-grid mode, energy storage can help the photovoltaic system to stabilize the output power and realize the self-sufficient power consumption mode of users. At present, our photovoltaic projects are all grid-connected projects, that is, they are directly integrated into the large power grid system after completion, and then used after the deployment of the large power grid. There is no doubt that users cannot directly use photovoltaic power in the grid-connected mode. This is the reason for the fluctuation of power generation, and it is also to solve the problem that the power station cannot generate electricity at night. In the off-grid mode, the photovoltaic system is loaded with the energy storage system, and its power does not need to be integrated into the grid, but can be used directly. At the same time, the excess electricity generated by the photovoltaic system can be stored by the energy storage system, so that there is no power outage at night.

At present, there are relatively few off-grid projects, mainly because the cost of energy storage systems is still high, and the current policy subsidies are more inclined to grid-connected projects. So off-grid models are often not as economical as grid-connected models. However, in some special scenarios, such as mountainous areas and rural areas where the power grid cannot reach, off-grid photovoltaic projects are also used. In the future, with the reduction of energy storage costs and the disappearance of photovoltaic subsidies, off-grid photovoltaic projects are expected to be promoted on a large scale.

The above is the help that energy storage brings to photovoltaic power generation in grid-connected mode and off-grid mode respectively. In addition, energy storage is also expected to help the photovoltaic industry to sprint the last mile of grid parity.

Helping photovoltaics in the last mile sprint

As we all know, in 2019, a large number of unsubsidized projects will begin to be constructed and connected to the grid. It is precisely because of this that many people call this year the first year of unsubsidized. But it is worth mentioning that not all areas of photovoltaic power generation have reached the grid parity level.

Judging from the current cost of photovoltaic power generation, only in a few areas with superior lighting resources, unsubsidized projects have the possibility of obtaining benefits. In this way, the construction and development of unsubsidized projects will be mainly concentrated in these areas with superior resources. But what is worrying is that some of the I resource areas representing the best light conditions have almost stagnated their market development.

According to the environmental monitoring and evaluation results of the photovoltaic power generation market in 2018, among the Class I resource areas, Jiayuguan, Wuwei, Zhangye, Jiuquan, Dunhuang, and Jinchang in Gansu; Hami, Tacheng, Altay, and Karamay in Xinjiang are red, and the other three Class I resources are red. The area is all orange. That is to say, in the five I resource areas, two areas cannot arrange the scale of new photovoltaic projects, and the other three need to carefully arrange the scale of new photovoltaic projects.

This means that in the Class I resource areas of Xinjiang and Gansu, which are most promising for the development of unsubsidized projects, they are the least able to build new photovoltaic projects. Moreover, these two provinces and cities are still in a state of abandoning light and limiting electricity all year round after not arranging new photovoltaic projects for many years.

In fact, the northwestern regions represented by Xinjiang and Gansu have good light resources, vast land and sparsely populated areas, which are very suitable for the development of photovoltaic power generation. However, it is also true that the northwest region has a small demand for electricity and few transmission channels, which has caused the problem of abandoning light and limiting electricity.

If the energy storage system can be built on a large scale in the northwest region, and the transmission channels along the way can be opened up, the photovoltaic power that cannot be used up in the northwest region can be easily transported to the central and eastern regions with high demand for electricity. In this way, photovoltaic power generation will be revived in the northwest region.

If there is no energy storage, the transmission and distribution channels and the storage of excess electricity will limit the development of photovoltaic power generation in the northwest region.

Summary

To sum up, as photovoltaic power generation gets closer to the era of grid parity, the shortcomings of its stability will be exposed. Under the breakthrough of energy storage, photovoltaic power generation can not only increase the application mode and expand the market scale, but also hope to break the dilemma of "abandoning light and limiting electricity" in the northwest region for many years, and add "flying wings" to photovoltaic power generation.