Essentially, the load forecasting and planning process involves at least six separate considerations.
These are as follows:
a) Impact of nominal load growth over time. Typically, some slight growth in kilowatt demand will be experienced over time. This may be upwards of 1/2 to 1% per year;
b) Impact of equipment changes due to new equipment installations or modifications that are not part of the product plan, including environmental equipment, new technology applications, or new requirements, such as facility air conditioning or air tempering;
c) New and modified production plans to meet requirements of the future product plan;
d) Additional site development due to new on-site building(s) and added floor space.. Typically, a site may be initially developed to a 15Ð20% building to land ratio, with an allowance for future development of upwards of 30%. Some sites may be constrained for additional development;
e) Impact of gas/oil conversion to electric use for some types of product heating where electric heating may actually be more economical due to inherent process efficiencies;
f) Other types of changes that cannot easily be categorized, such as higher density plant loading, etc.
Every plant should have a current business forecast, for Þve or six years of production and project requirements, that may be implemented. These, along with longer term projections, should be weighed in terms of their impact upon electric demand.
In similar fashion, the prospect of future expanded utilization of the site must be recognized in terms of electric demand. An array of probable plans for capacity can be developed to keep pace with the demands. If the full range of future possibilities is explored both as to size and timing, long-range plans
can be developed that can potentially meet demands.
While typically forecasted requirements for additional load occur later and are smaller than planned, the process is essential so that constraints, if present, are fully recognized and plans can be developed to resolve them.
Since forecasting offers a degree of certainty, it would be uneconomical to construct or provide capacity that is never used. However, there are opportunities in planning and designing electrical systems for selecting apparatus and arranging these in schemes that minimize the probabilities of early obsolescence due to improper ratings and the need for reconstructing major portions of the system.