**2.6 Discounted payback period**

Discounted payback period is a modified version of the payback period that accounts for the time value of money. This is the time period when the project cash inflows reach a 'break even' or to get the point where the net cash flows generated is equal to the initial cost of the project. Discounted payback period can be used to evaluate the profitability and feasibility of a project [10]. DPP can be calculated by solving the following Equation [11].

$$\sum\_{1}^{DPP} \frac{\text{CF}\_{n}}{\left(1 + r\right)^{n}} = \mathbf{0} \tag{7}$$

Where, *CFn* is the cash flow related to the *n*-th year and *r* is the discount rate. **Discounted payback period (DPP) has the following limitations**

