ISO New England (ISO-NE) recently published their Economic Planning for the Clean Energy Transition (EPCET) pilot study overview and initial benchmark scenario results. The EPCET study has three main objectives:
Take a deep dive into all input assumptions in economic planning analyses, propose updates to any assumptions based on our current experience, and test the effect of those modeling changes.
Gain experience in the features and capabilities of ISO-NE’s new economic planning software PLEXOS.
Perform a dry-run of the Economic Study process improvement currently being discussed with ISO-NE’s Transmission Committee.
As part of the 2021 Economic Study (Future Grid Reliability Study – Phase I), ISO-NE identified areas for improvement in their current Economic Study framework and the software tools used to perform the analyses. To address the areas for improvement in the software tools, ISO-NE did an extensive evaluation of Energy Exemplar’s PLEXOS software program in Fall 2021. After this evaluation, ISO-NE has obtained a license for PLEXOS for the EPCET pilot study, switching from its prior software provider.
PLEXOS is a powerful and robust production cost modeling program that ISO-NE has been able to use to model several concepts including:
Generator fuel-switching due to fuel constraints
Co-located energy storage and generation
Full AC power flow with N-1 secure dispatch
Distributed generation modeling
Robust automation programming interface
In addition, ISO-NE has highlighted the following as new production cost software features available in PLEXOS:
Constraint Class: PLEXOS has the ability to add custom constraints to the unit commitment algorithm.
Generator Fuel-Switching: If an incentive or fuel constraint is provided, generators will switch fuel types to minimize production costs.
Distributed Generation in Nodal Modeling: While previous economic studies have modeled New England as a 13 bus pipe and bubble model, PLEXOS nodal (bus level) simulations are feasible without excessive runtimes. PLEXOS allows an aggregate generator to split its profile into multipole nodes, which allows transmission flows to be evaluated at a granular level and under contingencies.
Contingency Modeling: Contingency modeling modifies the optimal dispatch to ensure protection of transmission assets. Contingency modeling also reports binding contingencies and their associated shadow prices to allow for calculation of the congestion cost of the contingency.
To read more about ISO-NE’s EPCET pilot study and see their preliminary results, view their report here. Overall, with assumptions that ISO-NE would typically use in an Economic Study and some additional fuel constraints modeling, ISO-NE is encouraged by the benchmark scenario results and satisfied with the PLEXOS unit commitment and dispatch logic.