What is a simple payback period and how is it used in WUE project evaluation?

• A. The annual rate of return on investment.
• B. The time required to recover the initial investment through avoided costs, used to compare project viability.
• C. The total lifetime savings divided by project cost.
• D. The time until production capacity increases.

Answer: (B)

The simple payback period is the time it takes for the investment to be recovered from the project’s savings, using avoided costs like reduced water bills, energy use, and other operating expenses. In WUE project evaluation, you estimate the annual savings from the measure and add them up year by year until they equal the upfront cost; that time span is the payback period. This metric is useful for quick viability screening and for comparing projects when budgets and liquidity are major concerns, because it shows how fast money is recouped. It doesn’t consider savings after payback or the changing value of money over time, so it doesn’t measure overall profitability—complement it with analyses like net present value or internal rate of return for a fuller view. For example, if a WUE upgrade costs $50,000 and saves $10,000 each year, the simple payback is 5 years.