Deterding, S., Dixon, D., Khaled, R. and Nacke, L. (2011a) âFrom Game Design Elements to Gamefulness: Defining âGamificationââ, Envisioning Future Media Environments - Conference proceedings, MindTrekâ11, Tampere, pp. 9â15.
The payback method is a simple way to evaluate the number of years or months it takes to return the initial investment. The payback period is usually expressed in years. Start by calculating net cash flow for each year: net cash flow year one = cash inflow year one - cash outflow year one.
The payback time of an energy-saving solution is a measure of how cost-effective it is. Here is the equation to calculate payback time: payback time (years) = cost of installation (Â£) Ã· savings per year in fuel costs (Â£) The double-glazing for a house costs Â£3,000 but saves Â£150 per year in fuel costs.