What are Flywheel Batteries?

Flywheel battery is a new concept battery that was only proposed in the 1990s. It breaks through the limitations of chemical batteries and uses physical methods to achieve energy storage. As we all know, when the flywheel rotates at a certain angular speed, it has a certain amount of kinetic energy. The flywheel battery converts its kinetic energy into electrical energy. High-tech flywheels are used to store electrical energy, much like standard batteries.

There is a motor in the flywheel battery.

Electric vehicles using chemical batteries have been tested for decades, but have not yet entered the practical stage. Solar energy, wind energy, tide energy, and wave energy all have storage problems. At present, chemical batteries are mainly used, but due to the limitation of the life and efficiency of chemical batteries, they have not been widely used so far. Many problems mentioned above have led people to seek a green energy storage device with high efficiency, long life, large energy storage, convenient use, and pollution-free. Unexpectedly, the ancient "flywheel" became the object of choice. [1]

The "flywheel" energy storage element has been used for thousands of years, from ancient spinning wheels to steam engines during the industrial revolution. In the past, its inertia was mainly used to balance the speed and break through the "dead point". The working cycle is very short, less than one second per rotation. In such a short time, the energy consumption of the flywheel is negligible. Now want to use the flywheel to equalize the energy for a period of 12 to 24 hours, the energy consumption of the flywheel itself has become very prominent. Energy consumption mainly comes from bearing friction and air resistance. People have changed the bearing structure, such as changing the sliding bearing into a rolling bearing, a hydrodynamic bearing, a gas dynamic bearing, etc. to reduce the friction of the bearing, and reduce the air resistance by vacuuming. 3. Even if it is so small, 25% of the energy stored in the flywheel is lost within one day, and it still cannot meet the requirements for efficient energy storage. Another problem is that conventional flywheels are made of steel (or cast iron) and have limited energy storage. For example, to achieve a balanced power generation of a power plant with a capacity of 1 million kilowatts, 1.5 million tons of steel are needed for the energy storage wheels! In addition, to complete the conversion of electrical and mechanical energy, a complex set of power electronic devices is also needed, so the flywheel energy storage method has not been widely used.

In 1994, the American Argonne (ANL) National Laboratory trial-produced an energy storage flywheel with carbon fiber: a diameter of 38 cm and a mass of 11 kg. The superconducting magnetic levitation was used. The energy it stores can ignite 10 100 watt bulbs for 2 to 5 hours. The laboratory is currently developing a 50 kWh energy storage wheel. The ultimate goal is to make it a 5,000 kWh energy storage flywheel. A power plant with a generating capacity of 1 million kilowatts requires about 200 such storage wheels.

In 1992, the American Flywheel System Corporation (AFS) developed a machine-electric battery (EMB) for automobiles. Each "battery" is 18 cm long, 23 cm in diameter, and weighs 23 kg. The core of the battery is a carbon fiber flywheel that rotates at 200,000 rpm. Each battery stores 1 kWh of energy. They put 12 "batteries" on the IMPACT sedan, which can make the car run at 100 km / h. Speed 480 kilometers. Motor-electric batteries weigh a total of 273 kilograms, and if lead-acid batteries are used, they weigh a total of 396 kilograms. The energy stored by motor-electric batteries is 2.5 times that of lead-acid batteries, and its service life is 8 times that of lead-acid batteries, and its "specific power" (ie explosive power) is extremely high, which is 25 times that of lead-acid batteries, and is gasoline 10 times the engine, it can accelerate the car from standstill to 100 km / h in 8 seconds.

What is a flywheel energy storage battery

The flywheel energy storage battery system includes three core parts: a flywheel, a motor-generator and a power electronic conversion device.

The power electronic conversion device inputs electric energy from the outside to drive the motor to rotate. The motor drives the flywheel to rotate. The flywheel stores kinetic energy (mechanical energy). When external load requires energy, the flywheel is used to drive the generator to rotate and convert the kinetic energy into

Comparison of flywheel battery and other batteries

The most widely used energy storage battery is undoubtedly

Due to the limitation of technology and material prices, the price of flywheel batteries is relatively high, and their advantages cannot be reflected in small-scale occasions. However, in the following occasions that require large-scale energy storage devices, the use of chemical batteries is also very expensive, and flywheel batteries have been gradually applied.

Flywheel energy storage technology is an emerging energy storage technology. Like superconducting energy storage technology and fuel cell technology, it is a promising energy storage technology that has appeared in recent years. Although the current chemical battery energy storage technology has developed very maturely, the chemical battery energy storage technology has problems such as limitation of the number of charge and discharge times, serious environmental pollution, and high requirements for operating temperature. This makes the emerging energy storage technology more and more important. Especially flywheel energy storage technology has begun to be used more and more widely in many industries at home and abroad. ^[1]