Free Environmental ROI calculator with clear step-by-step results.
Values an environmental project on two currencies at once: the cash it saves and the carbon it avoids, priced at your internal carbon price. The cost-per-tonne-abated figure is the one that lets you rank competing projects, and it goes negative when the cash savings alone justify the spend.
Annual net benefit
Net = cost saving + tonnes avoided x carbon price - additional operating cost
Cost per tonne abated
Cost = (capex - net cash saving x life) / (tonnes per year x life)
Corporate shadow prices commonly sit between $40 and $100 per tonne. Regulated markets set their own; use your compliance price if you are exposed to one.
The project pays for itself on cash savings alone, so the abatement is effectively free. Those projects should always be done first.