Enter the total energy input and the total usable energy output into the calculator to determine the thermal energy storage tank efficiency.

## Thermal Energy Storage Tank Efficiency Formula

The following equation is used to calculate the efficiency of a thermal energy storage tank.

STE  = Eo / Ei * 100
• Where STE % is the thermal energy storage tank efficiency (%)
• Eo is the usable thermal output of the tank (J)
• Ei is the total thermal input to the tank (J)

To calculate the thermal energy storage tank efficiency, divide the usable thermal output of the tank by the total thermal input to the tank.

## What is a Thermal Energy Storage Tank?

Definition:

A thermal energy storage tank is a device that stores excess thermal energy from a system. This thermal energy can then be used at a later time period.

The efficiency of a thermal energy storage tank depends on the type of storage and the length of storage. Shorter time periods will allow for higher efficiencies.

Like any thermal system, the efficiency is simply a ratio of the total energy that can be output by the storage tank relative to the total energy input.

## How to Calculate Thermal Energy Storage Tank Efficiency?

Example Problem:

The following example outlines the steps and information needed to calculate efficiency of a thermal energy storage tank.

First, determine the total excess thermal energy input into the storage tank. In this example, the total excess thermal energy is found to be 5000 J.

Next, determine the total usable output energy achieved by the storage tank. After a time period of 1 day, this storage tank outputs a total of 3000 Joules.

Finally, calculate the thermal energy storage tank efficiency using the formula above:

STE % = Eo / Ei * 100

STE % = 3000 / 5000 * 100

STE % = 60%