Assessing environmental, economic, and reliability impacts of flexible ramp products in MISO's electricity market

Increased variability and uncertainty of net electrical load due to high penetration of wind and solar power augments the need for dispatching conventional generators with sufficient ramping capability (RC) needed to balance demand with supply. Having sufficient RC reduces the need of last minute dispatch schedule modifications which cause cost, reliability and environmental outcomes that reduce the benefits of renewables. The Midcontinent Independent System Operator (MISO), has modified its Unit Commitment and Economic Dispatch algorithms to account for the economic value of provisioning adequate RC levels. This paper explores the outcomes of this modified market-clearing process by simulating 10-minute operations of a scaled MISO test system, for three representative months under low and high wind penetration scenarios. Changes in system performance are quantified by comparing system costs, scarcity events/pricing, energy prices, generation-fuel mix, wind-power curtailment, and CO2 emissions between the conventional market-clearing algorithm and one with flexible RC products. Results indicate that adding RC products lowers CO2 emissions and system costs, facilitates wind integration, and improves reliability. These benefits are robust to changes in the market clearing algorithm parameters such as over/under generation penalties and reserve scarcity prices.

Duke Scholars

Author Dalia Patino-Echeverri Environmental Sciences and Policy