Power generation is almost instantaneous. In conventional systems at a instant of time power generated = power consumed. Now a days non-conventional energy sources like solar and wind energy is getting connected with grid. Most of the non-conventional sources are time specific and unreliable in nature. Thus we need a good power storage solution to improve reliability and integrity of the power system. Batteries have been used for many years to store energy. But they are expensive and unsafe. In last decade many scientists ,entrepreneur has come up with different energy storage solutions. Here is the 5 brilliant methods to store solar energy without conventional batteries.
1. Compressed Air energy Storage (CAES)
When power demand is low excess energy is uses to run a compressor. The compressor compresses the air and stores in a underground tank. The underground spaces are easy available in mine areas. During peak demand the compressed air is heated and released. As the air expends, it is send trough a turbine. The kinetic energy of the expending air rotates the turbine. Hence the electrical energy is produced back.
Advantages: Cheap and pollution free.
Disadvantages: Requires suitable location for installing underground air tanks.
2. High Speed flywheels: During low power demand excess energy is used to drive a motor which is mechanically coupled with high mass extremely cylindrical flywheel. The flywheel stores kinetic energy which is again converted into electrical energy during peak demand. The loss due to air friction is very less as the flywheel is kept inside a vacuum chamber.
Advantages: Extremely fast response to load demand.
Disadvantages: Can store energy only for few minutes, commonly 15 minutes. A new innovation in flywheel can store energy for as long as 30 to 45 minutes.
It is one of the 5 brilliant methods to store solar energy without conventional batteries.
3. Pumped Hydro Energy Storage System:
During low demand time water is pumped to a higher altitude reserver usually on hilltop using excess energy generated. The water stores energy as potential energy. During peak demand stored water is released and passed through a turbine. The potential energy is converted to kinetic energy. Hence makes the turbine to move annd generate electricity back.
Advantages: Storage huge amount of energy at relatively low cost. Storage installations lasts a half-century or more.
Disadvantages: Needs proper geographical location and good initial investment.
4. Flow Battery Energy storage system: It is the best among the 5 brilliant methods to store solar energy without conventional batteries. It is not a conventional sealed battery. Here electrolytes can move freely between reserver. The working principle is same as conventional battery. As large amount of electrolytes are stored the capacity of the battery also becomes large.
Advantages: Large amount of energy can be stored at relatively cheaper price than conventional batteries. batteries can be Repaired unlike conventional batteries.
Disadvantages: Space is required to store the large tanks of liquid. Risk of pollution from leaking sometimes makes it unreliable.
5.Molten salt Energy storage system: Here molten salt acts as a heat transfer fluid. Hundreds of mirrors concentrates the sunlight on a molten salt storage tank placed on the top of a tower. It heats the molten salt around 1000 degree F. The salt stores the thermal energy. During load demand the stored thermal energy turns water into steam to drive a turbine.
Advantages: It’s an efficient energy storage technique for large scale solar installation.
disadvantages: It requires lots of space for mirrors and tanks.
Apart from these 5 brilliant methods to store solar energy without conventional batteries, there are many methods suggested by experts. Some of them are listed below.
- Cooling water energy storage
- Dummy train energy storage
- Grid connected vehicle energy storage.