As an example, a graph of life cycle savings against the collector area is shown in Figure 12.1. For this graph, all other parameters except the collec tor area are kept constant. As can be seen, the life cycle savings start at a nega tive value for a collector area equal to 0, representing the total value of money required for fuel for a non-solar energy system, and as solar collectors are added to the system, the life cycle savings reach a maximum and then drop. An increase collector area beyond the maximum point gives lower life cycle savings(than the maximum value), as the bigger initial expenditure required for the solar energy system cannot replace the cost of the fuel saved It even gives nega tive life cycle savings for large areas in multiplication of the optimum value, which represent the money lost by the owner in erecting and operating the solar energy system instead of buying the fuel.