Without robust incentives, their payback can range from 10 to 15 years or more, depending on electricity rates and use patterns. . How long does it take for the energy storage cabinet to pay back? 1. It is usually expressed as a percentage and reflects the overall profitability and efficiency of the investment. ROI (%) = (Total Lifetime Revenue – Total Investment Cost) ÷ Total. . Below is a reworded, easy-to-follow guide to estimating ROI, how incentives change the picture, and realistic payback timelines today. In many places, time-of-use. . Calculating the payback period is like having a financial compass – it guides decisions for businesses, utilities, and even homeowners. 5 years through frequency regulation services – beating initial. .