Energy & Sustainability worked example

Sustainability Project Payback with project capital investment of 187,500 $: a worked example

Push project capital investment up to 187,500 $ and the picture changes. This example computes every intermediate figure at that operating point. a sustainability manager or finance lead needs a first-pass payback for an efficiency or carbon-reduction project

The inputs for this scenario

  • Project capital investment: 187,500 $ (raised for this scenario; the documented default is 75,000)
  • Gross annual cost savings: 52,000 $ / yr (unchanged)
  • Annual support and verification cost: 8,000 $ / yr (unchanged)

Working through the calculation

  • Applying the documented formula (Net annual savings = gross annual cost savings - annual support and verification cost) to the inputs above produces each figure below.
  • At this operating point the engine returns 4.26 yr for sustainability project simple payback, the number this scenario is built around.
  • At this operating point the engine returns 44,000 $ / yr for net annual sustainability savings.
  • At this operating point the engine returns 187,500 $ for project capital investment.
  • At this operating point the engine returns 32,500 $ for five-year net value after investment.

How this compares with the baseline

  • Against the tool's baseline example, where project capital investment sits at 75,000 $ and the headline result is 1.7 yr, this scenario comes in 150% above the baseline at 4.26 yr.
  • It computes simple payback in years by dividing project capital by net annual savings, where net savings are gross cost savings minus annual support and verification cost. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Sustainability project simple payback: 4.26 yr (headline result)
  • Net annual sustainability savings: 44,000 $ / yr
  • Project capital investment: 187,500 $
  • Five-year net value after investment: 32,500 $

Run it with your numbers

  • Every input above is editable in the live Sustainability Project Payback calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.