THERMAL ENERGY STORAGE

Thermal energy storage systems are considered one of the most important load displacement techniques, effectively contributing in reducing and shifting the peak loads that represent the biggest burden to electricity facilities, technically and economically.

Advantages of Thermal Energy Storage:

Thermal energy storage stores the power during nighttime to take advantage of the low external temperatures and lack of demand for electricity and then uses the stored energy during the daytime hours to provide the power plants or buildings with the required cooling energy.

The significance of thermal energy has become more compelling when generated electrical power from power plants does not meet the requirements of the electrical loads that peak at certain times of the day during the summer. It is proven that instant expansion is needed in the generation capacities and networks reinforcement. This forms a high investment cost and technical burdens for SEC to meet the demand for electrical power; specifically, in the case of air conditioning loads that results in increase in maximum loads coinciding with the highest temperature leading to peak load for a short duration of time.

When demand for electrical power is low, thermal energy storage displaces the required electrical load during peak hours until the evening (lowest electric consumption periods).

Thermal energy is produced during off-peak electrical demand where chilled water or ice cubes are collected in thermal energy storage tanks, then withdrawn and distributed to the facility during peak periods. Cooling water enters and passes through these tanks and as a result, the cooling units (chillers) help in reducing the electricity needed to run AC compressors and pumps due to the decrease in temperature when water enters or exits the cooling unit. The temperature drops when the cooling water exiting the building passes through the unit and absorbs the heat from it through coils inside the cooling tanks. Consequently, temperature decreases and then the thermal load drops during the peak period; and all these will help in reducing the power consumption and pressure on the power plants.

Another advantage of the thermal energy storage system is that it reduces the number of cooling units, electrical loads, pumps and AC piping​.

In case this system is applied in an existing building, it can be expanded and cooled by the same cooling units of the building before the expansion while adding cooling tanks instead of increasing the capacity of cooling units.

Types of Thermal Energy Storage:

The power is stored in these systems either by using chilled water, ice or special types of salts as a storage medium. Since water is cheap and has good properties compared to salts, water is commonly used for power storage purposes, whether in its liquid or frozen state.

Cases Where Thermal Energy Storing Is Regarded As a Practical Solution :

1- Places requiring high cooling loads for a limited time during the peak period throughout the day. (The total floor area of the space to be cooled is about 2,600 square meters or more).

2- Places that consume large amounts of electricity for many purposes, including air conditioning, which forms the highest load (at least, 30% - 50% of the total electricity consumption of the building).

3- Low price of electricity during periods of minimum load in order to rationalize the consumption of electric power within the peak hours throughout the day.

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Methods of Encouraging the Customers to Use Thermal Energy Storing:

- Applying the Time of Use (TOU) Tariff program and providing discounted tariff outside the peak hours.

- Reduction or cancellation of customs duties.

- Giving priority entitlements for commercial clearances and licenses to manufacturers and suppliers of high-efficiency appliances, and facilitating the procedures.

- Developing regulations to encourage importation and usage of high efficiency appliances.