The average construction cost for utility-scale energy storage systems ranges between $200-$500/kWh. For a 1GW system with 4-hour duration (4GWh capacity), total costs typically fall between $800 million and $2 billion. Cole, Wesley and Akash Karmakar. . As capacity increases, the cost per unit of energy storage typically decreases due to reduced equipment and construction costs per kilowatt-hour. This in-depth analysis provides invaluable insights for potential investors. Let's simplify the math and. .