The term “generation schedule” is used in the energy industry to describe – simply put – the sequence of operations at a power plant, i.e. the timetable for planned generation. Schedules are particularly important for optimising power plant operation, because for profitable operation many influencing factors need to be taken into account on an ongoing basis:
- current market prices for the various electricity products
- current market prices for fuels used in thermal power plants (gas, coal, oil)
- current market prices for CO2 emission rights
- technical parameters (minimum load, maximum ramp-up/ramp-down time, ramp-up costs, etc.)
- contractual obligations (e.g. supplier contracts)
- district heating supply
Long-term optimisations in a generation schedule are calculated on the basis of futures market prices in order to hedge the income generated by the power plant over the long term. Power plants can also generate income from the volatility of the futures market by adapting planned outputs to take advantage of current conditions. The actual output of the power plant is determined by short-term optimisation calculations based on the spot or intraday prices shortly before delivery. If the power plant participates in the balancing services market, optimisation calculations are also used to select the best bid.
However, optimisation of an individual power plant or an entire power plant fleet does not automatically ensure the security of supply of an energy transmission system. To ensure security of supply at all times, it is necessary to take grid system operation measures or to intervene in the market so as to eliminate grid congestion, supply-demand imbalances or other system operation issues. The aforementioned mechanisms also include redispatch measures (interventions to adjust the power in-feed from plants to the requirements of the transmission system operator) in order to avoid or eliminate grid congestion and thus ensure stable system operation.