The modularity and scalability described have a major positive impact on achieving a low cost of ownership, but costs are held down too by designs that have best-in-class energy efficiency. ABB’s Conceptpower DPA 500, for example, operates with an efficiency of up to 96 percent. Its efficiency curve is very flat so there are significant savings in every working regime. Further, cooling costs can be substantial and, because less power is consumed, high-efficiency modular UPSs require less cooling effort, creating further savings.