Studying the loss allocation, it is possible to determine the loss which appears in some grid section or line (allocated power loss) as a result of: 1) some power source sending its power to the consumers, 2) some power source sending its power to a certain power consumer, 3) power received by some consumer. Determining allocated power losses, it happens that some of them are negative. It turned out that this phenomenon is not rare and appears at a definite power distribution between suppliers. Negative allocated power loss shows that total power loss is increased. Computing the allocated loss, the possibility appears to define other grid quantities that characterize grid properties and operation, as well as to find out those suppliers and consumers who mainly affect the grid operation