Written by: Zhang Yitian
Huayu News At the beginning of the new year, Xiaomi founder Lei Jun announced a set of "air charging" system on Weibo. A large space charging pile with a computer host can locate the mobile phone within a few meters of the surrounding space in milliseconds, and transmit millimeter waves to the mobile phone through beamforming to achieve 5W power charging, even if there is a foreign object in the middle, it will not affect the charging effectiveness.
▲The indication of Xiaomi's "charging in the air". (Screenshot of Xiaomi's promotional video)
This technology is very reminiscent of the future world of science fiction writers, "like floating in a sea of electricity".
Compared with mobile phones that never lack power, this technology may have greater potential in the field of Internet of Things. Many small sensors will not need to consider power supply, and achieve rapid deployment like "spreading beans into soldiers". Electricity is being deployed by the Chinese in time and space using magic methods.
丨 Power transmission thousands of miles, more electricity, but also more flexible
"Strive to achieve a carbon peak by 2030 and achieve carbon neutrality by 2060" is the grand blueprint for the Chinese to tackle climate change. To achieve this goal, using clean energy to change China's current coal-based power generation method is the first priority.
China’s hydropower, wind power and photovoltaics are mainly concentrated in the western region, while the vast majority of population and electricity demand are concentrated in the east. In order to change this mismatch situation, China used long-distance power transmission technology as early as the 1980s. Continue to study on.
In October 1990, the Gezhouba-Shanghai DC transmission project was put into operation. As China's first ±500 kV DC transmission project, it opened the prelude to the era of ultra-high voltage DC transmission. As the transmission voltage is getting higher and higher, the power loss is getting smaller and the distance that can be transmitted is getting longer and longer, and the deployment of power across thousands of kilometers has become commonplace in China. The Tibet Power Grid even announced at the end of 2020 that in the past six months, they will send 100 million kilowatt-hours of clean energy from the Qinghai-Tibet Plateau through the UHV grid to Xiongan, Hebei, across China.
▲The Wudongde Hydropower Station sends power to the Guangdong Guangxi UHV multi-terminal flexible DC demonstration project with a total length of 1452 kilometers, passing through the four provinces (districts) of Yunnan, Guizhou, Guangxi and Guangdong. (Picture from Science and Technology Daily)
Today, China's long-distance power transmission project has shifted its focus from "further" to "more flexible". According to a report by Science and Technology Daily, before the new year of 2021, a major power transmission channel in southern China, which has created 19 projects in the world, was put into operation half a year ahead of schedule.
This "UHV", "multi-terminal" and "flexible" transmission line connecting the world’s seventh largest hydropower station Wudongde Hydropower Station and Guangdong and Guangxi can transmit 33 billion kilowatt-hours per year, all of which are renewable energy, equivalent to Reduce coal consumption by 9.5 million tons and reduce carbon dioxide emissions by 25 million tons every year.
The traditional UHV power transmission can send electricity to far away, but how to use it after delivery is still a problem. The electricity that is continuously sent is like a steel giant, able to run fast, but it is difficult to control, even if it has to stop, there will be a lot of inertia. The power receiving party often needs to prepare more and more flexible power supplies locally for matching to absorb the impact it has on the local power grid.
This "flexible DC" line from Wudongde to Guangxi, Guangdong is characterized by more flexible control of voltage and frequency, just like a fully controllable water pump, which can precisely control the direction, speed and flow of water flow. The electricity it sends is not only no longer an impact on the local grid, but also supports the safe and stable operation of the system at critical moments.
Science and Technology Daily introduced that the realization of this breakthrough is the continuous upgrade of "Made in China". The key equipment of the flexible DC converter valve is called the "heart" of the project. Now the world's first domestic "heart" capable of withstanding ±800 kV UHV has been stably "beating" at the Longmen Converter Station. Some of these advanced technologies will be applied to the upcoming offshore flexible DC project and will be used for reference by foreign manufacturers; IGBT key chips will break the monopoly of a few foreign manufacturers.
丨 Industrial enterprises use "power banks"
is the world’s largest producer and consumer of electric vehicles,More and more fields in China are enjoying the "spillover effect" of this industry.
According to the Tongzhou Daily reported by Nantong, Jiangsu media, as of the end of January 2021, more than a dozen small and medium enterprises in the area have used energy storage facilities. The characteristics of these companies are their rapid business development, and the limited capacity of the power facilities of the originally rented workshops, which will incur relatively high costs if the capacity is increased.
The energy storage facility is like an extra-large “power bank” that can be charged at night when the electricity price is cheap, and is reserved during the day to assist in powering the factory. Take a local furniture factory as an example. They installed a 350KW/2MWH energy storage system, which can fully charge 2000 kWh in 5 hours.
According to reports, the battery of this charging system is mainly from the cascade battery replaced by electric vehicles, and the cost is cheaper than the power increase. Using cheap valley electricity at night to supplement the expensive peak electricity during the day can save thousands of yuan in electricity bills every month. Electric drying equipment that was previously limited by electricity can also be used with confidence, and the production capacity has been greatly improved.
▲The "unpredictable" characteristics of wind power, radio and television and other clean energy power generation make it more necessary for the cooperation of energy storage systems. The picture shows Qinghai Zhongkong Delingha 50MW CSP station in operation. (China News Network data map)
Energy storage uses the same lithium batteries as electric vehicles, and is always limited by lithium resources. Therefore, many Chinese companies place their hopes on new technologies such as flywheel batteries and hydrogen energy. In September 2020, China achieved the first 35kV grid-connected flywheel energy storage equipment in Liaoning.
According to the Shenyang Daily report, unlike the aforementioned lithium battery energy storage device installed on the power end, the flywheel battery here is used for the power generation end. The so-called flywheel battery is to allow the flywheel to rotate rapidly in a closed, close to vacuum environment, storing energy in the form of kinetic energy, and use the flywheel to drive the electric motor to generate electricity when needed.
has the advantage of fast charging and discharging, and the energy stored per unit volume and weight even exceeds that of fuel oil. The disadvantage is that it requires extremely high parts processing technology and natural energy loss. Used in conjunction with clean energy power generation methods such as wind power and photovoltaics, it can just neutralize the large fluctuations in its power generation capacity. It stores electricity at high load and discharges at low load to deliver electricity to the grid stably.
丨 Nuclear power breakthrough takes the lead in living water
Want to truly let the Chinese "float in the ocean of electricity", no matter how well the electricity is deployed in time and space, the absolute amount of electricity that can be generated must also Go up. Clean energy such as water, wind, and light generally requires the use of specific natural conditions. If you want to achieve truly "sufficient" clean energy, nuclear power is still one of the best choices.
On January 30, 2021, the world's first "Hualong No. 1" nuclear power unit, Fujian Fuqing Nuclear Power Unit 5, has completed the full-power continuous operation assessment and was put into commercial operation. As the "national business card" of China's nuclear power going to the world, "Hualong One" is one of the most widely accepted third-generation nuclear motors in the world's nuclear power market. The first batch of commercial operations has laid a solid foundation for the mass construction of "Hualong No. 1" and its expansion into the world.
▲The world's first reactor of "Hualong One"-China National Nuclear Corporation Fuqing Nuclear Power Unit 5. (The picture is from "State-owned Xiaoxin")
According to reports, the "Hualong One" has a design life of 60 years, a reactor core design of 177, a core design refueling cycle of 18 months, and innovative use of "active and passive" phases. Combined with technologies such as safety systems and double-layer containment, it meets the highest international safety standards in terms of safety. All core equipment has been domestically produced, and the localization rate of all equipment has reached 88%. It is fully capable of batch construction.
"Hualong No. 1" each unit can generate nearly 10 billion kilowatt-hours of electricity per year, which can meet the annual electricity demand for production and life of 1 million people in moderately developed countries, and it is equivalent to reducing standard coal consumption by 3.12 million tons and reducing carbon dioxide emissions 8.16 million tons.
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