A Combined Pool/Bilateral/Reserve Electricity Market Operating Under Pay-as-Bid Pricing

A pricing model considering the simultaneous interaction of pool, bilateral and reserve markets in a power system is presented. The model is able to work under the classical marginal pricing (NIP) or under the pay-as-bid (PAB) pricing. In the PAB pricing approach, an integration process involves an ac optimal power flow (OPF) for obtaining awarded bids in the pool and reserve market considering the presence of long-term firm bilateral contracts. As a result, prices of energy and reserve services incorporate the influences of topology, voltage levels, losses, capacity limits of generators and transmission lines. Results show that agents can plan their portfolios based on prices reflecting the impact of supplying several electricity services and associated costs of resources in several operation scenarios and bid strategies. From the perspective of the system regulator, the minimization of payments by PAB ensures the supply of energy, transmission losses and reserve requirements besides enforcing financial adequacy. Numerical cases are presented for evaluating the model.