Power plants in basic load mode run round-the-clock to cover basic consumption.
Wikipedia definition (similar term):
Base load power sources are power stations which can consistently generate the electrical power needed to satisfy minimum demand. That demand is called the base load requirement, it is the minimum level of demand on an electrical grid over 24 hours. Historically, large power grids have used base load power plants exclusively. However, there is no specific technical requirement for this to be so. The base load requirement can equally well be met by the appropriate mix of intermittent power sources, peaking power plants, hydroelectric power and other sources.