Explain the four stages of high-ratio renewable energy applications

How to make renewable energy use in high proportion in the power system? What is the path to a high percentage of renewable energy applications? The requirements for the inverter are different at each stage. Now it is nothing more than doing distributed + storage energy into micro-networks, different stages of automation inverters are completely different.

The application of high proportion of renewable energy is mainly divided into four stages, distributed photovoltaic development, distributed + energy storage, multi-energy complementary microgrid and regional energy management platform.

A high proportion of renewable energy is used, and distributed PV has developed very fast in the past two years. The relationship between distributed and power grid can reduce the loss caused by long-distance transmission. The distributed scale is small, the number is large, geographically dispersed, invisible, unschedulable, and management is very difficult. Instant delivery is rigid and it is not friendly to the grid. Some places are super-issued, but there are regulations. In many areas, only 25% of the park's power grid communication is proposed. As the cluster is connected to the grid, only 10% of the grid is exchanged.

Distributed PV must be used in a high proportion. First, we must add energy storage. How much? Can't you simply add storage? An important problem with adding storage capacity is that it has been talking about volatility to solve problems. The volatility of wind power and photovoltaics is real. Nowadays, new energy is used to replace traditional energy. Solving volatility by itself requires traditional principles to solve it. You need to prepare a book for you. Now you have to replace it, and a high percentage of it will be eliminated. It is impossible to break through in technology. Now the energy cost of energy storage is high, and how to reduce the cost of electricity is very important. The cost of the system should be reduced. The biggest problem of energy storage is the reduction of power supply costs. How to improve the efficiency of the system? In the same system, the energy storage system can do 85% well, and the lithium battery can do 90%. The electricity cost is very large. Many batteries do not change much after running for a while, but they float. How to make online adjustments and online replacements, we have to break through some technologies. The fixed cost of Shanghai project has dropped to about 0.5 yuan, and the peak-to-valley electricity price difference is 0.91 yuan. Tibet has a pure energy storage system. We used some lead carbon and some lithium batteries, and the cost of electricity was reduced to 0.45 yuan. However, the conditions given by the Tibet Power Bureau are very good. The PV on-grid price is 1.15 yuan, but Tibet PV has 30%, which gives us a dime or two cents. If the energy storage system wants to make a profit, it must pay attention to the cost of electricity. How to increase your electricity cost is the key to the application of energy storage system. To achieve this, the market is infinite. Yesterday, the battery manufacturers discussed that they believe that the cost of batteries will fall below 50% in the next three years. At that time, the cost of electricity was three cents, and the space was infinite. A high proportion of renewable energy, you must solve the problem of volatility, do not expect the power plant to solve. We use distributed, and now the entire grid is still a large grid, or centralized power and power generation. The development of electric power is developing towards fragmentation and compound development. Now pay attention to a problem, security and stability. In addition to energy storage, the next step is to solve the problem of multi-energy complementary and micro-grid. Photovoltaic + energy storage, if you only do this model, then even less than a year in the year will be a problem. Because it is not effectively monitored, the battery is short-boarded and can be problematic if the battery is broken.

Multi-energy complementary systems are complex. What problems does the energy management system solve? Photovoltaic power generation, energy storage, wind power generation, gas development, voltage sources, current sources, power electronic converters, synchronous generators. Power generation fluctuations, load changes, and energy storage differences. The requirement for inverters for pure photovoltaic power generation is one-way. To be more complementary, there are more requirements for the inverter. In 2013, 7.2 MW of photovoltaic and 28 MWh of energy storage system was completed in Qinghai. 20,000 kWh per day for three consecutive years. At that time, we used a part of the lithium battery, a part of lead acid as a backup for energy storage, photovoltaic has no problem for three consecutive years. What are the requirements for the inverter, and the parallel operation of multiple inverters is required. At that time, one inverter was 500K, and we used eight inverters to form a four megawatt inverter. We have done three projects in Qinghai, four megawatts of photovoltaics and 40 megawatt hours of energy storage. There must be economics, and no economics will not work. We are preparing to acquire California's energy storage project, which is itself serving the grid. After going to find a very big problem, PCS 5 can only allow the battery to store energy according to 0.25C. When the power grid requires it to make adjustments, the capacity is not enough. In addition to the services of grid energy storage, peaking requires battery charging and discharging capability and frequency modulation is completely different. What to do when a system needs FM peaking is a problem we need to solve. After solving this problem, the economics of the system are significantly improved. If the system is purely peaking, the rate of return is less than 6% globally. But if the FM is lowered, it can reach 10%.

Tibet's system we have 18 devices in parallel at the same time, 20 MWh. I have been saying that a high proportion of renewable energy replaces traditional energy sources and complements them. When a community can complement each other and rely on the grid to become smaller and smaller, the dependence is only 25%, and then reduced to 10%. This model can be promoted on a large scale, and when it is economical, the replacement of the energy revolution is a natural occurrence.

The trend of replacing traditional energy sources with renewable energy is unstoppable. When I go to California, they should do photovoltaics to make photovoltaics. Renewable energy replaces traditional energy and leaves blue sky and white clouds for future generations. This is our common mission and mission. In Canada, the gas-fired Power station is equipped with energy storage for frequency modulation and peak shaving. The technology of energy storage and peak shaving needs to be solved, and energy storage is used for frequency modulation. Now we can achieve one hundred milliseconds and one hundred milliseconds, we have to make a technological breakthrough.

The large-scale application of renewable energy, the key to the current technology is energy storage. Energy storage is not without technology, the cost performance of energy storage should be improved, how to improve the cost performance? The intelligent inverter is to make multiple inverters run in parallel and perform parallel conversion in parallel. If you don't convert online, your portfolio and power supply will not keep up when the fluctuations change. How to control the high-power storage power station. We have to turn the energy storage of distributed energy storage into concentrated energy storage. I believe that with the breakthrough of technology and the establishment of photovoltaic power plants, especially the decline in the cost of lithium batteries and lead carbon batteries, this is seen. See you.

In addition to piloting in the United States, Canada, and Australia this year, we have also done several projects in China. Beijing has set up a department, and the current funds are very popular. In just two months, there were more than 5 billion funds invested by interested companies. It is necessary to study the real research of this technology and study it well.

Multi-energy complementary microgrid solutions – reducing honors, optimizing portfolios, combining several different power sources, managing strategies and control strategies are important. Mixed energy storage, scientific matching, some people talk about the use of lithium batteries and lead carbon batteries when talking about energy storage, this is not the case, it can be mixed with energy storage. Now in Tibet is a mix and match, why must we have a lithium battery? When the system fluctuates, we can quickly charge and discharge, and the normal lead-carbon battery can be used. Give me four hours of charge, four hours of release, the price is completely different, to mix and match, enhance the system flexibility, fine control of energy storage and discharge characteristics. The control model we are talking about needs to be changed. The reliability of fault tolerance is very important. How to deal with running errors? How to make online improvements, this is what we need to think, otherwise the system will not be stable.

Traditional energy storage systems are also so volatile that they are not suitable for traditional models. The supply side needs to undergo great changes. Many problems in the microgrid are in energy storage. The energy cost of energy storage is 0.51 yuan, and that of lead carbon batteries is 0.31 yuan. The core of multi-energy complementarity is the energy management system. The stability is minute-level, the economy is hourly, and the optimization is week, month and year. At the beginning, the microgrid should have a stable operation and economical operation strategy, and there must be a learning function in the middle of the operation. The energy storage control strategy and control mode are automatically and non-automatically adjusted to ultimately optimize operation and optimize based on user behavior and database.

Regional energy management platform. Any single-machine power grid, even if the unit is bigger, one million, two million, the system may still have problems. The stability of a single microgrid on the Internet is also flawed, so it becomes the control of the microgrid group. There is a microgrid on the roof of your home, which is the sale and transaction of the partition wall. There will be many micro-network groups, and some micro-network groups will be few. At this time, power transactions will automatically appear. The stability of multiple microgrid groups is certainly better than that of a single microgrid, and the demand for power grids is gradually decreasing. If the large grid needs to exchange 25% of energy, the system is stable. Distributed to distributed + micro-network control, we walked step by step. There must be less and less reliance on the grid. The load on the park and the load on the area are only stable for renewable energy, and economical to replace it.

These have high requirements for inverters, and virtual synchronous generator tests must be connected to the grid. The certification platform has four analog networks that are simultaneously open to the public. The system is placed on the cloud platform. Only by making breakthroughs in technology, only the market itself is yours, otherwise the market will never be yours.

A high proportion of renewable energy, energy storage technology applications and applications of microgrids and microgrid groups. The introduction of the response policy on the demand side is very important. The Australian electricity price is adjusted once every five minutes, California is adjusted once every 15 minutes, and the low electricity price and high electricity price can be more than three times. The demand side response is not forcing you to use less electricity. When people's electricity prices fluctuate, you don't charge and discharge, there will be more opportunities for charging and discharging, and the profit will be big. Nowadays, many heat storage rooms have turned on the heaters in the middle of the night, and they are turned off during the day, naturally introducing the load. Use the electricity price mechanism to control you. The electricity price in Germany on the same day is completely different. China's electricity price mechanism is brought about by the big power grid. The transformation of centralized power generation to distributed power supply Whether it is new energy or power grid, renewable energy instead of traditional energy is not a market competition problem, but a human survival problem. We must work harder in the field of new energy. I believe that the use of high-renewable renewable energy will definitely be achieved.