# Net Energy Yield

Last updated: March 8, 2016

## What Does Net Energy Yield Mean?

Net energy yield is the amount of energy gained from an energy source, minus the amount of energy spent harvesting it.

Net energy yield is an abstract concept that is neutral about the source of energy in the equation. Whether it is solar radiation, fossil fuels, geothermal energy, or any other type of energy, the concept can be applied without modification. That being said, it is most commonly used in reference to nuclear fuel, biomass, and hydrocarbon fuels.

## Safeopedia Explains Net Energy Yield

The first step to calculating net energy is to estimate the total amount of energy that a resource will generate over the course of its projected lifetime. Then, an estimate of the amount of energy used by the various processes involved in extracting and refining the product so it is available for use. The difference between these two estimates will be the estimated net energy yield of a resource.

### Return on Investment

The Energy Return on Investment (EROI), which is related to the net energy yield, is used to express the profitability of bringing energy products to the market. To have a positive value, the EROI must at least show that the energy used is less than the energy produced. In other words, it must not have a net energy yield below zero.

To produce energy, the energy sector receives two inputs from the economy:

1. Inputs in the form of energy to run its equipment (S1)
2. Inputs in the form of human-made capital such as a plant in place to extract energy – S2

The net energy yield will be = P – (S1 + S2)

Where,

P = Gross production by the energy sector

The net energy ratio is given by (NER) = P / (S1 + S2)