Assessment of revenue potentials of ancillary service provision by flexible unit portfolios

This paper examines the revenue potentials of frequency control provision (primary and secondary control) by flexible unit portfolios, also referred to as Virtual Power Plants (VPPs), consisting of generators, energy storage units, and controllable thermal loads. A unified modeling approach for power system units, referred to as“Power Nodes modeling approach”, is introduced and used for setting up an optimization-based control strategy. Time simulations over parameter ranges are undertaken so as to determine the control potential provided by two benchmark portfolios. Ancillary service market data from Switzerland is used to assess the value of using energy-storing units for frequency control instead of generators only. This yields a quantitative evaluation of the commercial potential of control services by coordinated flexible unit portfolios.