Curtail Renewables to Enhance Flexibility: A Regulated Forecast-based Dispatch Approach

A team of researchers has published a counterintuitive paper proposing that intentionally curtailing renewable energy output can actually enhance overall grid flexibility and reduce costs. The paper, 'Curtail Renewables to Enhance Flexibility: A Regulated Forecast-based Dispatch Approach' by Zhiyi Zhao, Ye Guo, Zhenjia Lin, and Yinliang Xu, introduces a Regulated Forecast-Based Dispatch (RFBD) model. It addresses a critical problem in modern power systems: high penetration of variable energy resources (VERs) like wind and solar creates excessive demand for flexible ramping products (FRP) to balance the grid. This demand, based on forecasts, can paradoxically constrain real-time flexibility and distort economic efficiency through a phenomenon the authors term the 'unit dispatch transfer effect.'

The proposed RFBD approach works by moderately capping VER outputs during the day-ahead or intra-day scheduling phases. Simulations demonstrate that a strategic 5-10% curtailment of renewable generation can reduce FRP requirements by approximately 15% and lower total system operating costs. This is achieved by freeing up conventional generators from being overly committed to providing flexibility reserves, allowing for a more economically optimal and physically feasible dispatch. The research, hosted on arXiv, provides a formal mathematical framework and could influence how grid operators and regulators design market rules for systems with high renewable penetration, shifting the paradigm from 'use all renewables at all times' to a more nuanced, system-optimal approach.