In
electrical engineering
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...
the load factor is defined as the average load divided by the peak load in a specified time period.
It is a measure of the utilization rate, or efficiency of electrical energy usage; a high load factor indicates that load is using the electric system more efficiently, whereas consumers or generators that underutilize the electric distribution will have a low load factor.
An example, using a large commercial electrical bill:
* peak demand =
* use =
* number of days in billing cycle =
Hence:
* load factor = (
/ / ) × 100% = 18.22%
It can be derived from the
load profile
In electrical engineering, a load profile is a graph of the variation in the electrical load versus time. A load profile will vary according to customer type (typical examples include residential, commercial and industrial), temperature and holi ...
of the specific device or system of devices. Its value is always less than one because maximum demand is never lower than average demand, since facilities likely never operate at full capacity for the duration of an entire 24-hour day. A high load factor means power usage is relatively constant. Low load factor shows that occasionally a high demand is set. To service that peak, capacity is sitting idle for long periods, thereby imposing higher costs on the system. Electrical rates are designed so that customers with high load factor are charged less overall per kWh. This process along with others is called
load balancing or peak shaving.
The load factor is closely related to and often confused with the
demand factor
In telecommunication, electronics and the electrical power industry, the term demand factor is used to refer to the fractional amount of some quantity being used relative to the maximum amount that could be used by the same system. The demand facto ...
.
The major difference to note is that the denominator in the demand factor is fixed depending on the system. Because of this, the demand factor cannot be derived from the load profile but needs the addition of the full load of the system in question.
See also
*
Availability factor
The availability factor of a power plant is the amount of time that it is able to produce electricity over a certain period, divided by the amount of the time in the period. Occasions where only partial capacity is available may or may not be deduc ...
*
Capacity factor
The net capacity factor is the unitless ratio of actual electrical energy output over a given period of time to the theoretical maximum electrical energy output over that period. The theoretical maximum energy output of a given installation is def ...
*
Demand factor
In telecommunication, electronics and the electrical power industry, the term demand factor is used to refer to the fractional amount of some quantity being used relative to the maximum amount that could be used by the same system. The demand facto ...
*
Diversity factor
In the context of electricity, the diversity factor is the ratio of the sum of the individual non-coincident maximum loads of various subdivisions of the system to the maximum demand of the complete system.
: f_\text = \frac
The diversity factor ...
*
Utilization factor
The utilization factor or use factor is the ratio of the time that a piece of equipment is in use to the total time that it could be in use. It is often averaged over time in the definition such that the ratio becomes the amount of energy used d ...
References
{{Electricity delivery
Power engineering