Financial evaluation should convert technical alternatives into comparable cash-flow profiles. Net Present Value (NPV), payback period and discounted cash-flow analysis are common tools for doing this.
Build the cash-flow model
Identify initial investment, recurring operating cost, maintenance, replacements, energy savings, avoided cost and residual value over the selected study period.
Use NPV for time-value comparison
NPV discounts future cash flows to a present value using a selected discount rate. Positive NPV indicates that benefits exceed costs under the model assumptions.
Use payback carefully
Simple payback is easy to understand but ignores benefits after the payback point and may ignore the time value of money. It should not be the only decision criterion for long-life infrastructure.
Test uncertainty
Electricity tariff, utilization, equipment life, maintenance cost, escalation and discount rate can materially change results. Sensitivity and scenario analysis should therefore accompany the base case.
Link finance to technical assumptions
If an energy-saving project depends on a particular load profile or operating mode, that assumption should be traceable to engineering data rather than inserted as an unsupported financial estimate.
References
- ISO 15686-5:2017, Life-cycle costing.
- ISO 21502:2020, Guidance on project management.
