The adoption of new market mechanisms - vital to the better integration of flexible assets - depends on the fairness and nondiscrimination of the pricing rules. We consider a market setting with time-flexible unit energy buyers and sellers, that additionally submit their availability in time. The time-flexibility of the agents allows for different schedules to be equivalent with regard to social welfare, which can lead to arbitrary price differences, i.e. price discrimination. In this work, we demonstrate that non-discriminatory prices are not trivially defined in time-flexible settings, provide a definition of non-discrimination as consistent over equivalent outcomes, show that this concept does not conflict with individual rationality and, finally, compare our work to broader concepts of fairness from economic psychology.

In order to reduce CO2 emissions, energy systems using different energy carriers (e.g., heat and power) are becoming more intertwined and integrated. However, coordination between non-cooperative participants of these systems in the combined heat and power domain has been limited to single-sided auctions with one centralised seller. In this paper, we present a double-sided auction mechanism in which prosumers as well as consumers and producers of heat and power can participate. By showing that our mechanism is Incentive Compatible and Individually Rational, we ensure that truthful bidding is the optimal strategy, simplifying the bidding process and thus accommodating agents with limited computational resources. Finally, we show that our mechanism is fiscally sustainable, i.e., Weakly Budget Balanced.