What is unit commitment? Explain it by genetic algorithm?

In electricity generation and distribution by a large number of generators connected to a grid, whose load can vary with time and location, it makes sense to optimise which unit generates how much and when to minimise overall costs. Unit commitment is the amount of electricity committed to be generated by each generator station as per a given schedule.
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Since there are many variables, an optimisation programme called the genetic algorithm has been developed for this. Though effective, it tends to be very computer intensive.
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