Because people's energy has a strong time and spatiality, in order to reasonably use energy and improve energy utilization, it is necessary to use a device to collect and store excess energy in a period of time in a period of time. Get up, use it at the peak, or use it to be used to the place where energy is scarce. This method is energy storage.

The basic task of the energy storage system is to overcome the difference between time or locality between energy supply and demand. There are two cases of this difference. One is caused by sudden changes in energy demand, that is, there is a problem of peak load. The use of energy storage methods can adjust or buffer when the load change rate increases. Because the investment cost of an energy storage system is relatively lower than the construction of a peak load factory, although the energy storage device will have storage losses, because the storage energy is from the excess energy or new energy from the factory, it can still reduce the fuel cost Essence The other is caused by reasons such as first energy and energy conversion devices, the task of energy storage system (device) is to make the energy output balanced, that is, not only the peak of energy output, but also to fill the output volume. Low valley (that is, reclamation).

For example, in the solar heat utilization system, the energy storage device needs to be set. The working principle of solar thermal use is shown in Figure 1. After the heat flow leaves the heat collector, the energy storage device is available, and then the thermal machine is provided by the thermal converter. In the case of no sunlight, the cold flow was directly passed through the energy storage device, the storage heat was extracted and passed on to the thermal machine.