Efficiency

Question 1

Define energy efficiency

Answer 1

Energy efficiency = Useful output of a process/Energy input into a process

According to IEA, something is more energy efficient if it delivers more services for the same energy input, or the same services for less energy input.

E.g. for the industrial sector energy efficiency can be measured as the amount of energy required to produce a tonne of a product.

Question 2

How can energy efficiency be measured?

Answer 2

1. Thermodynamic-thermodynamic
2. Physical-thermodynamic
3. Economic-economic
4. Economic-thermodynamic (favoured and vice versa ratio)