Comment by everfrustrated

>Pretty much all electricity markets worldwide set the unit price based on the the cost of the "marginal" (most expensive) generator running during each time period

Indeed. This is inherent failing of the use of auctions for setting price. While using auctions is a laudable goal, in reality it is not very efficient and easily gamed. Having a central purchaser model is not idea from a ideological standpoint but clearly more efficient allowing correctly controlling for more variables than can (crudely) be transmitted through a 30 minute auction period.