"Building a new power system with new energy as the main body" is the latest major decision made by the state on the development of the power system under the background of carbon peak and carbon neutrality.
Under the guidance of China's dual carbon target, around 2035, new energy with scenery as the main body will account for more than 50% of the total installed capacity. In the long term, photovoltaic and wind power will account for more than 70% of the power generation. A high proportion of new energy capacity access, on the one hand, the power system needs to change from "source with load" to "source network load storage" cooperative interaction operation mode, so as to solve the uncontrollable problem of the power supply end; On the other hand, the reliability of the new power system for the new energy generation itself has also put forward far more than the previous requirements, only to ensure the "safety and reliability" of the system, the next is to consider the predictability of its generation, and network, load, storage interaction.
1. New power systems must maintain high reliability
Under the background of carbon neutrality, the electrification level of energy production and consumption will be significantly improved, and the harm of power restriction and blackout to production and life will be significantly increased. For example, at the end of 2019, due to the shortage of coal and the pressure of dual control of energy consumption in some regions, electricity rationing occurred in some regions, resulting in the soaring price of raw materials (such as silicon metal), which greatly impacted the middle and downstream manufacturing industries. The suspension of electricity supply in some parts of northeast China made it difficult for people to continue their daily life.
So, as the status of the new energy from the auxiliary energy to the main energy, new power system reliability requirements for new energy power generation system will be far more than in the past, new energy power generation facilities in life cycle needs to have the ability to resist all kinds of extreme weather, otherwise once the blackout accident, the economic loss will be unable to estimate:
The blackout events such as the UK in 2019, derived from gas generator outage caused by lightning, the outage led to the decrease of the power grid frequency, caused 750 mw offshore wind turbines to take off the net, the grid frequency reduce lead to low frequency load shedding and further more the generator set to take off the net, resulting in large parts of England and wales blackouts, around 1 million people are affected by power outages.
Another example is the power failure crisis in Texas in the United States in early 2021: on the one hand, the cold wave led to a significant increase in demand for heating power; on the other hand, 26GW of thermal power and 5GW of wind power failed to work due to lack of gas and low temperature, resulting in power failure affecting more than 4 million households.
Second, photovoltaic power generation as the main force of new energy, to ensure its reliability needs to curb the component size surge
Photovoltaic power generation is to use solar energy to generate power by arranging photovoltaic modules in the open space and on the roof. It can not only generate power centrally in desert areas, but also use distributed power generation on residential roofs and industrial and commercial roofs. Photovoltaic power generation has predictability and controllability. At present, it is the lowest cost power generation method in areas with good irradiation, so it will become the main force of new energy power generation.
Because pv modules are exposed to the outdoor environment for a long time, they need to continue to operate for 25 years or even longer life cycle, which requires the product design to be extremely reliable, to withstand various weather changes, including a once-in-a-century snowstorm, hurricane, hail and other meteorological disasters. Otherwise, once a place has extreme weather, it will lead to a large number of photovoltaic module damage in the region, power stations can not generate electricity, resulting in large-scale blackouts. This kind of power failure is not a simple failure to disconnect, but also involves the reordering, replacement and installation of photovoltaic modules, with a long time cycle.
However, fierce competition in the PV industry has led to a big leap in module size since 2018, with mainstream PV modules increasing from 2 square meters to 2.2 square meters and even 2.6 square meters (power increased from 370W to 540W).
The commercial success of individual products led to the emergence of large size worship in the industry, irrational think that size can always grow, power was shouted out 600W, 700W and even 1000W...... , no longer care about snow load, wind load, hail and other meteorological conditions on the boundary size restrictions. For example, some companies have introduced super-large components with an area of 3.1 square meters. Although the power is more than 650W, the width of the glass is more than 1.3 meters, and the reduction of toughened strength makes it unable to withstand the impact of hailstones with a diameter of 35mm.
It is understood that under static and dynamic load tests, huge deformation will lead to excessive power attenuation of the components, and even serious risks such as frame tearing and glass breakage. At the same time, the very large current associated with the very large components also significantly increases the probability of junction box and terminal failure. In this high-risk situation, on the one hand, the size of modules is still growing, on the other hand, the thickness of photovoltaic silicon wafers is also continuously thinning due to the high price of photovoltaic silicon materials, and the safety and reliability of photovoltaic modules are threatened by double.
In the context of building a new power system with new energy as the main body, photovoltaic practitioners should pay more attention to the quality safety and reliability of products rationally and prudently. The irrational pursuit of ultra-high power and super-size by some manufacturing enterprises and downstream non-professional enterprises can easily lead to bad money driving out good money. The landslide of component reliability level will also bring immeasurable hidden dangers to the safe operation of new power system. From the stable and reliable "rigid" demand of the power system, the photovoltaic industry should stop the size of the inner roll in time, abandon impetuosity, and return to the "true innovation" of product efficiency improvement.
Wuhan Xinshengneng is a professional power testing equipment manufacturer. We pay close attention to the development and trends of power grid related industries. For more information, visit our official website: www.whxsn.com
