**energy efficiency formula**is a method of calculating the efficiency of energy production and consumption. It can be used to measure the efficiency of infrastructure, facilities, buildings, transport, products and services.

## Energy Efficiency Formula

The energy efficiency formula is based on energy output and input.**energy efficiency = (energy output / energy input) × 100**Energy output is the useful energy offered by an item such as the light generated by a light bulb.

## Example 1

A solar module produces up to 320 watts of power from 1500 watts of sunlight.**energy efficiency = (320/1500) × 100 = 21.3%**

## Example 2

An electric car consumes 20 kWh of power on a drive and transfers 10.5 kWh of power to the wheels.**energy efficiency = (10.5/20) × 100 = 52.5%**

## Example 3

A gasoline burning car consumes fuel with an equivalent of 60 kWh of energy on a drive and transfers 11 kWh of power to the wheels.**energy efficiency = (11/60) × 100 = 18.3%**

## Similar Measurements

The energy efficiency formula is a technical measurement that isn't always useful in comparing real world efficiencies. A large number of alternative measurements are commonly used. For example, energy per passenger mile is a common way to calculate efficiency for transportation.Overview: Energy Efficiency Formula | ||

Type | ||

Definition | A method of calculating the efficiency of energy production and consumption. | |

Related Concepts |