These two types of auctions are most commonly used in the energy trading markets. What would be advantages and disadvantages of each? And in the end, can we expect them to deliver similar outcome?
One, quite obvious disadvantage of PAB auction is the need to "guess the clearing price". If not all generators correctly predict the MCP, more expensive generators may be scheduled at the expense of cheaper ones, resulting in higher costs for the same payment by consumers. But what can be considered as a disadvantage of uniform price auction here? And what are the advantages of each auction type?
As for the second question, I think we can expect the same (or at least very similar) outcome when we consider the perfect competition? Under perfect competition all players would know what the marginal production unit is for any given level of demand, so that under pay-as-bid they would all bid at the marginal cost of that unit - achieving the same outcome they would obtain under uniform price auction by bidding at cost. How would the outcome change if we consider (bit more realistic) case of oligopoly?