Simple payback — Science definition
Upfront cost divided by annual savings in a simplified model.
Where it is taught
- Environmental Design & Evidence-Based Capstone — Conservation, Systems & Environmental Design, Physics & Environmental Science, Grade 12
In use
A simple payback estimate is upfront cost divided by annual savings; it ignores discounting, maintenance changes, and uncertain future prices.
Environmental Design & Evidence-Based Capstone
Questions using simple payback
Problem 1
An upgrade costs 500 units and saves 100 units/year. Find simple payback.
Hints
List the given quantities, select a relationship, and check units before substituting.
Answer and explanation
5 years
500/100=5, excluding other costs.
Problem 2
Cost 900 units,annual savings 300. Find simple payback.
Hints
Write the relationship first; substitute with consistent units.
Answer and explanation
3 years
900/300=3.