A lot of Alternative Energy Storage Methods are available now a days. The various Technologies / resources for Alternative energy storage are discussed.
Apart from battery i.e. a chemical based energy storage method, many other techniques have been gradually invented as Alternative Energy Storage methods. They are being practically used for various high-power applications. However, if we keep the capacitors apart, almost all of them has not been able to hit the mass market till to date.
Types of Alternative Energy Storage Methods:
- Thermal Battery
- Molten Salt Battery
- Ice Battery
- Fly Wheels
- Compressed Air Energy Storage (CAES)
- Hydraulic Storage (Pumped Storage)
- Superconducting Magnetic Energy Storage (SMES)
- Radio-isotope Thermoelectric Generators (RTG)
It is also known as Electrostatic Battery. The reason for being called so is that they store energy in an electrostatic field. A capacitor can be charged when a voltage is applied across the terminals of capacitor. The capacitors are being used from the time even before the battery’s invention. Old data confirms that the scientists of 18th century were using Leyden Jars as a power source for their experiments.
Next in the list of Alternative Energy Storage methods is ‘Thermal battery’. We can classify thermal batteries (direct conversion) in two main categories. They are Thermo-couple converter and Alkali Metal Thermal Electric Converter (AMTEC). Thermo-couple converter works on the principle of Seebeck effect while Alkali Metal Thermal Electric Converter works on the principle of Electro-chemical heat engine. Both of these thermal batteries transform heat energy into electrical energy.
Molten Salt Battery
As the name suggests, it contains a high capacity thermal salt. This type of battery absorbs the solar thermal energy and dispense it during night for generation of steam that in turn drives the steam generator and so provides a continuous power supply to the user.
It is a thermal energy storage system specially designed for air-conditioning system. The basic function of this system is to accumulate low temperature during night and provide the low temperature next day.
Storage of energy can be done in a spring by winding it up in a clock-work device. When the winded spring is released in a controlled manner, it can be used for driving a dynamo which in turn generates electricity on rotation. Trevor Baylis radio is best example of storage of electrical energy in spring.
The technique of storing energy using Fly wheel is thousands of years old. The concept of Fly wheels to be used as a mass energy storing device in modern age is being used since 1950s.
Now a days, advanced Fly wheels contain the kinetic energy in a fast moving rotary drum which acts as rotor of a generator. At the times when additional energy remains unconsumed , then it is used to boost the rotary drum’s speed. Whenever there is requirement of energy, then this drum drives the generator.
Compressed Air Energy Storage (CAES)
Next in the list of Alternative Energy Storage methods is CAES. CAES stands for Compressed Air Energy Storage. It stores energy in the form of highly pressurized air. During off peak electricity tariff hours, a motor compressor is driven by power to compress the air and store it in a storage tank. During peak hours, this compressed air from the storage tank is released in a controlled manner and mixed with other gas to for driving a generator attached with gas turbine.
It is also known as Pumped storage. This hydraulic storage is the simplest way of storing energy and generating electricity to compensate high peak demands. The surplus electricity is used to pump water into a upper tank during off peak electricity tariffs hours. Whenever there is requirement of electricity, the water is released back into the lower tank via a turbine. The flowing water rotates the turbine which in turn produce electricity. The round trip efficiency of this system is 70-80 %.
Superconducting Magnetic Energy Storage
Next in the list of Alternative Energy Storage Methods is Superconducting Magnetic Energy Storage. They are also known as SMES systems. In this system, Dc flows through a big magnetic coil and creates a magnetic field in it. This magnetic coil is cooled to a low temperature below its critical super conduction temperature so that electricity flows through it without resistance. The current flowing through the coil may be converted into alternating current as and when required. SMES is commercially available in the market.
Radio-isotope Thermoelectric Generators
The last in the list of Alternative Energy Storage Methods in this post is Radio-isotope Thermo-electric Generator. They are also known as RTG batteries or Nuclear Batteries. It was intentionally designed for spacecraft functions and for enabling availability of power to remote sectors like a light house. It was invented in 1960s.
RTG batteries works as a nuclear heat generator. In this system, heat is produced by the natural decaying of radioactive isotope of radioactive substance (Plutonium) and is further used for generating electricity in a Thermo-electric generator.
They have a very long life span. Till to date, the early batteries are still in operation mode even after three decades.