The calculated payback is based on assumptions that net metering laws will not change over the life of the array, that GCEA’s rates will go up by X%, and that GCEA’s rate structure will not change. The forecast for future rates is not provided by GCEA and is sometimes overly pessimistic. Net metering laws are beginning to change across the country and there is a good chance something will change in Colorado during the life of the system which could reduce the cost recovery of the system. It is also probable that GCEA's rate structure will change in the coming years. 75% of GCEA’s costs to provide service are fixed and do not vary based on how much energy a member uses, while our current rate design recovers only 25% of GCEA’s costs through a fixed charge on the member’s bill. GCEA’s future rate structure will, of necessity, change and will likely include a higher monthly fixed charge as well as time differentiated rates to recognize the lower cost, and value, of wholesale power when the sun is shining and the additional cost of power caused by peak demand after sunset.