Population as an index to electrical development

IN making plans for the future in the electrical utility business it is necessary to make estimates of future growth. Various methods have been used. The usual method is to plot growth of one kind or another against time. This gives an upward curve which is difficult to project mathematically and usually is misleading if projected ahead more than two or three years in a rapidly growing territory. In the electrical utility field various values have been plotted against the number of consumers or meters. This is all right for past data but for the future the number of meters or consumers would have to be estimated and this would depend upon the increase in population, especially if all the present population now had service. This led to the use of population as the abscissa rather than time or consumers with any of the values desired as ordinates. This gives a straight line for practically all present values and the future is a straight line projection with a simple formula. The lower end of the line does not usually cross both zero points and this fact gives the changing values per unit of population.