Abstract: There is provided a system for supplying power to a site having a load. The system comprises a number n of power source units, the value of n being greater than or equal to 3. The system further comprises a number t?tmax of loads groups, each load group having a number i of inputs. The value of i is greater than or equal to 2 and less than the value of n. Each load group receives power from i power source units, such that each load group is connected to a unique combination of i power source units. tmax is such that every possible combination of i power source units is connected to a unique load group.