Siting and operating incentives in electrical networks: a study of mispricing in zonal markets

The incentives electricity generators face in investment and output decisions hinge on market design. Under some zonal market designs, where profit-maximizing participants face a uniform regional price, achieving lowest-cost system-wide production can be impossible. Further, zonal designs can incentivize siting of intermittent renewables in inefficient locations behind network constraints, of concern for jurisdictions undergoing a clean energy transition. We develop measures of mispricing that compare the zonal prices generators receive to locational marginal prices that value congestion externalities from generator output. We apply these measures to show wind and solar generators are increasingly siting in constrained areas of the Australian network, and highlight sources of potential efficiency gains from adopting a nodal market design with locational marginal pricing.