Transportable Utility-scale Energy Storage System to Reduce Curtailment and Constraint of Renewable Energy Sources

Project Description

An innovative utility-scale transportable energy storage system (TESS) will be developed to reduce curtailment and constraint of renewable electricity generation. A single unit, or a group of TESSs, can be connected to the grid at different locations at different times, creating the opportunity to provide the required grid services in a much more cost effective manner than traditional stationary energy storage systems scattered around the network (with low utilisation). Transportability offers the ability to deliver localised active and reactive power support (in terms of curtailment reduction, grid congestion mitigation, voltage regulation, etc.), to facilitate dispersed RES integration, and to defer transmission and distribution upgrades. Sodium-nickel chloride batteries, as a sustainable lithium free battery technology, are utilised in the storage system. An innovative coordinated control and management strategy will be implemented for the TESS units, involving a hierarchical control structure, with grid congestion control actions co-ordinated centrally, while, at an individual TESS level, buffering of high renewable power injections will be performed, while also providing power and voltage support at the specific node or district. Optimisation models, implemented in General Algebraic Modelling System (GAMS), will be developed to determine the optimal location, schedule and number of TESS units for specified scenarios (recognising renewable generation and demand forecast profiles, and existing network configuration), considering the power/energy capacity, movability, cost and physical size of the TESS units. The cost benefits of TESS for mitigating dispatch down will be assessed to determine technology viability, while for validation testing, a small-scale powertrain system of the proposed TESS will be developed and connected to real-life models of distribution and transmission networks via an Opal-RT hardware-in-the-loop real-time simulator setup.