Lastkurven

Lastkurven, or load curve, is a graphical representation of the variation in electrical load over time, typically shown for a 24-hour period. The term is used in German-speaking and some Nordic contexts; in English the equivalent term is load curve. It plots the instantaneous demand on the vertical axis (usually in MW) against time on the horizontal axis. The area under the curve over a given interval corresponds to the total energy consumed in that interval (MWh).

Load curves are used by electric utilities and grid operators for planning and operating power systems. They inform unit commitment and economic dispatch, determine required generation capacity and reserves, and help assess transmission needs. Understanding the shape of the curve supports demand forecasting and demand-side management, including demand response programs.

The typical daily load curve exhibits a diurnal pattern: lower demand overnight, a morning rise as activities begin, a peak in the late afternoon or early evening, and a fall at night. Weather, season, day of the week, holidays, and economic activity strongly influence the curve. Extreme weather can create pronounced peaks or valleys that challenge system reliability and ramping capabilities.

Related concepts include base load (the minimum level of demand during a period), peak load (the highest demand), the load duration curve (a sorted representation of demand over time), and the merit-order curve used for dispatch decisions. The load curve is a planning and operating tool that reflects how demand shapes generation and transmission needs.