New York Grid Performance Gaps Study

This study exemplified such an integrated planning approach by first assessing reliability gaps associated with New York’s significant renewables buildout to identify the quantity and performance attributes of potential fossil-replacement solutions. Adequacy, production cost analysis and stability screening were performed for scenarios with significant solar and wind buildout in a system with significant transmission constraints. The analyses indicated that fossil-replacement solutions need to ramp quickly at 6pm to support evening demand, especially in the New York City area during low-wind conditions, while grid-forming voltage support. The study team then tested four scenarios of fossil-replacement solutions encompassing combinations of batteries, flexible loads, clean thermal resources, and transmission upgrades and observed the following.

• Adequacy and production cost analysis mostly showed that these Solutions Scenarios were reliable from capacity and operational perspectives. • Production cost analysis showed that with very high penetrations of storage and lower levels of dispatchable resources, there could be hours of insufficient battery charging energy depending on how their state of charge is managed. • Daytime battery charging was coincident with daytime peak demand thus significantly increasing overall peak loading. Such a phenomenon may not present a reliability risk if the transmission system can support power flows. • Renewables curtailment was lowest in scenarios with relaxed transmission constraints. • Production cost analysis showed that battery siting is challenging when renewables and load centres are on opposing sides of a transmission constraint. • From a stability perspective, the solutions scenarios identified likely require more gridforming capacity. Such capacity could include synchronous condensers or grid-forming batteries. Further investigations into the practicalities of siting and cost associated with these solutions can help inform next steps for the State. At the same time, electromagnetic transients modelling can help define stability solutions. Such modelling is currently underway.

This effort has shown the value of an integrated planning approach as applied to New York’s ambitious energy transition.