In Electrical Engineering, a load curve is plotted between time and electrical load.
A load curve shows the variation of load on the power station with respect to time.
Recommended reading: Power Generation MCQs
Load curves are generally plotted for a day, month, or for year. Given below are a few types of load curves.
Daily Load Curve
A daily load curve has the load variations that are plotted during the whole day (24 hours) on a half-hourly or hourly basis and are plotted against time on the graph. The figure below displays a daily load curve.
On the X axis hours in a day are presented, while on the Y axis load units in MW are presented. It is evident from the daily load curve that the load on the power station is varying throughout the day. The maximum load demand is at 19:00.
Good to know: Highest point on daily load curve represents maximum demand
Monthly Load Curve
The monthly load curve is an extension of the daily load curve and it can be obtained from the daily load curves of that month. In order to achieve a monthly load curve, average values of power over a month at different times of the day are calculated and then plotted on the graph. Applications of monthly load curves involve is to fix the rates of energy.
Yearly Load Curve
The yearly load curve is achieved by considering the monthly load curves of that particular year. The yearly load curve is generally used to determine the annual load factor.
Also see: 13 Most Important Formulas on Variable Loads Every Power Engineer Should Know