Thoughts on conceiving a “fair” value for flexibility

•Addressing the question of what the objective value of flexibility is, independently from market interactions.•3-step methodology for the global pricing of flexibility and the definition of price catalogues.•Three techniques for distribute the price of total flexibility amongst various flexibility resources.•Deterministic cost curve to protect the value of the end-user’s supply of flexibility.•Stochastic cost curve to protect the value of the value of the DSO’s demand of flexibility.