It depends on your view point and the model you are making. Generally it will be your cost of capital to be used as a discount rate. Say if you borrow at 10%,

It depends on your view point and the model you are making. Generally it will be your cost of capital to be used as a discount rate. Say if you borrow at 10%, then you need account for that every year you need to wait for that return. A company with access to cheap capital can use a lower discount rate, and come up with higher net present value based on distant cash flows compared to a company that needs to pay a lot. Net present value is a normalization measure.