Enter the total energy output (J) and the total energy input (J) into the Return on Energy Invested Calculator. The calculator will evaluate and display the Return on Energy Invested. 

Return on Energy Invested Formula

The following formula is used to calculate the Return on Energy Invested. 

EROI = EO / EI * 100
  • Where EROI is the Return on Energy Invested (%)
  • EO is the total energy output (J) 
  • EI is the total energy input (J) 

To calculate the return on energy, divide the energy output by the energy input, then multiply by 100.

How to Calculate Return on Energy Invested?

The following example problems outline how to calculate Return on Energy Invested.

Example Problem #1:

  1. First, determine the total energy output (J).
    • The total energy output (J) is given as: 175.
  2. Next, determine the total energy input (J).
    • The total energy input (J) is provided as: 350.
  3. Finally, calculate the Return on Energy Invested using the equation above: 

EROI = EO / EI * 100

The values given above are inserted into the equation below and the solution is calculated:

EROI = 175 / 350 * 100 = 50 (%)

FAQ

What is the significance of calculating Return on Energy Invested (EROI)?
Calculating the Return on Energy Invested (EROI) is crucial for assessing the efficiency and sustainability of various energy sources. A higher EROI indicates that an energy source produces more energy than it consumes, making it more efficient and potentially more sustainable in the long term.

How can the Return on Energy Invested (EROI) impact decisions in energy production?
The EROI can significantly impact decisions in energy production by influencing the selection of energy sources. Energy sources with higher EROI values are often preferred as they are more efficient and have lower environmental impacts, leading to more sustainable energy production strategies.

Can the EROI vary between different energy sources?
Yes, the EROI can vary significantly between different energy sources. Renewable energy sources like solar and wind often have different EROI values compared to non-renewable sources like oil and coal. This variation is due to differences in the amount of energy required to extract, process, and deliver the energy compared to the amount of energy they produce.