Ancillary Services Optimization

Ancillary Services Offer Optimization for hydro-thermal generation portfolios

The ancillary services markets have become more interesting for energy producers, especially for hydro power, as these markets hold huge potentials for extra profit. Although there higher margin prospects, offering to the ancillary services markets requires an integrated decision making framework which is a challenge for energy producers. The decision between offering the energy to the spot or an extremely complex and a risky task. The crucial challenges have been resolved in our solution. Our solution concisely:

Optimal integrated decision about sales/purchases of

  • electricity,
  • fuels,
  • ancillary services

in multiple markets. The decision framework captures the entire hydrothermal generation portfolio with all delivery obligations and price curves of different markets.


  • Quantification of opportunity costs of ancillary services delivery
  • Stochastic offer optimization: Optimization of the ancillary services offer decisions under consideration of short-term uncertainties
  • Stochastic long-term optimization: Involvement of the uncertainty about ancillary services (quantity/price) in the long-term resource management
  • Uncertainty of a call for ancillary services delivery and  the amount of energy to deliver as well as the congruent amount of water and empty space to hold out
  • Technical restrictions of the transmission service operator for each turbine and pump in the form of different minimal power bounds for each ancillary services market
  • Detailed allocation of the offered type and amount of ancillary services to each turbine and pump
  • The result is an optimized ancillary services and spot market offer stating for each turbine, whether and how much it delivers power to the  spot, primary, secondary and the tertiary market

Essential Inputs

  • Ancillary services products (delivery period and block structure)
  • Lot size
  • Minimal amount to offer
  • Remuneration for energy and power capacity
  • Call probabilities
  • Parameterization of assets according to the prequalification (eligibility concerning type and direction of frequency control, minimal spinning reserve etc.)