Unfortunately, wind and sun, the two most important sources of renewable energy, do not always provide the desired energy. Energy can be produced from these two sources only at certain times. Therefore, energy storage is of great importance. There are various batteries and methods to store energy.
Sand batteries work very efficiently
Each storage method has several advantages and disadvantages such as efficiency, size, location, installation costs, operating costs, lifetime and how long it can store energy. One or more of these methods can be preferred according to environmental factors.
Now, a new one has been added to the energy storage methods. The company called Polar Night Energy started using the first commercial sand batteries in Finland. The basis of this system is an insulated steel tank about 4 meters wide and 7 meters high.
The thermal energy storage system is made with a simple heat exchanger buried in the middle of the sand. When this system is heated to 500-600 degrees, it becomes an impressive 8 megawatt-hour energy store with a rated power of 100 kW. This energy can be released as heat in the same way when necessary.
The stored heat will be used to feed the district heating system, which is used to conduct heat around the area. The system can then be used to heat buildings and pools. In addition, this system can also work for industrial processes that require heat.
This system, which is used in more than one place, thus becomes very efficient. Polar Night CTO Markku Ylönen has the following statements about sand batteries:
It’s really easy to convert electricity into heat. But you need turbines and more complex things to go back from heat to electricity. As long as we only use heat as heat, the process is really quite simple.
The company claims its new systems offer up to 99 percent efficiency. These sand batteries, which have the ability to store heat for months with minimum loss, can be used for many years. The company says that the sand they use should be dry and free of combustible residues. Apart from this, it is stated that there is no special situation related to sand.
It is seen that this system, in which the operating cost is kept to a minimum, is quite efficient. Of course, this system, which has a limited area of use, may not be suitable for every business. However, it is a fact that these heat coils do their job quite well.
So what do you think about energy storage in sand? Do you think it is an efficient method? You can share your views with us in the comments section.