In the load management approach, DSM refers to the control of customer load to improve utility operations. It comprises all those activities, services, products, tariffs, regulations, policies, or any combinations of these which will influence the time, pattern, and magnitude of participating customers' electrical loads and affect the timing or amount of electricity used through customers.
Thus, DSM programme of a utility has to match customer consumption patterns of electricity, that is, load characteristics, as closely as probable to current or projected capabilities of the power supply facilities. In this connection two factors are important: peak load and load factor.
Peak load is easily the highest stage of electricity demand in a given time- span, commonly in one day or in one year.
Load factor is the difference among the average demand and the peak demand over that given time.
Although a low load factor is bad, a high load factor is not essentially good. Equipment requires routine, failures and maintenance happen. A power supplier must have sufficient reserve margin to cover these events.
DSM programmes are used to eliminate or decrease the requirement for additional peak or base load generating capacity and/or distribution facilities through controlling customer loads. The goals are to decrease the peak load and to increase the off peak usage of energy. DSM can be used to effectively manage the system valleys and peaks.
Load management is carried out to decrease peak load, for example, by segregation of agriculture load. The peak demand could also be decreased through spreading out the consumer load more evenly over the entire daily or weekly period. Load leveling technologies are used to smooth out the peaks and dips in energy demand through reducing consumption at peak times, shifting the load from peak to off-peak periods, or increasing it during off-peak times.
We now elaborate the DSM techniques used through power utilities for managing the customer load.