Thermal energy storage

What is thermal energy storage?

• a technology in which thermal energy is stocked by heating or cooling a storage medium

• solar heating

• a technology to generate steam

• a technology to extract electricity from water

Why do we need thermal energy storage?

• Stored heat is renewable

• To increase efficiency of powerplants

• To trap heat that will otherwise escape

• Stored thermal energy can level demand by storing energy when there is less demand and releasing when there is high demand.

What are the three main types or classes of thermal energy storage?

• Solar, CHP and fuel cells.

• Nuclear, Coal and fossil fuel

• Micro turbines, batteries and air-tanks

• Sensible, latent and thermo-chemical

What type of energy storage principle is used to release heat in this example?

• Campfire

• Electricity

• Solar

• Chemical

What type of energy storage principle is used to store heat in this example?

• Flow of fluid or gas

• Electrical energy

• Solar energy

• Sensible heat storage

What does the term "Cp" refer to in the following expression: 𝑄 = 𝑚 ∗ 𝐶𝑝 ∗ ∆𝑇?

• stored energy

• temperature

• mass of the material

• specific heat of the material

Use the excel-spreadsheet from class-room activity to answer this question.

In the same heat storage plant, the expected heat storage capacity needs to be increased to 20 GWh (at 100% efficiency). What total size (m³)of storage cavern will you recommend using"sea water" as medium.