The NAS battery: a multifunction energy storage system

Towards an objective method to compare energy storage technologies: development and validation of a model to determine the upper boundary of revenue available from electrical price arbitrage

“…To further demonstrate the capability of the algorithm, it is used to find the upper boundary respectively. The battery system is based loosely on a Sodium Sulphur (NaS) system, with a typical efficiency of around 85% (Tamyurek et al, 2003), however the focus is to demonstrate the capability of the model rather than on the specific efficiency values. The time constant for the Pumped Hydro and Hydrogen storage is set at 10 years whereas the time constant for the battery storage system is set at 830 hours.…”

“…Another promising variant for larger scale non-mobile applications are the Sodium Sulphur batteries (Tamyurek et al, 2003), which have relatively high efficiencies (in excess of 85%) and long cycle life. Although often quoted as having no self-discharge, they must be constantly heated to keep them at temperatures around 300 o C, which can effectively be converted into a time-dependent loss depending on the level of insulation.…”

Utilizing Energy Storage for Reliability Solutions in Active Distribution Systems

“…DERs can help reduce the impact of sag event by injecting an additional reactive power in case of voltage dips during system contingencies [7]. The energy storage installed at customer premises can override short-and long-duration reliability events [8,9]. Microgrid, which consists of controllable loads and DERs integrated at the point of common coupling (PCC) of distribution network, operates in isolated mode during utility supply disturbances (sags and interruptions), thereby protecting critical load against reliability events [7,10].…”

“…A new method of protecting sensitive load against momentary interruptions using inverter-coupled ESS is developed in Reference [9]. The potential of sodium-sulfur batteries to protect customer devices/processes are investigated in Reference [8]. Authors in Reference [7] have discussed the role of DG in the mitigation of reliability events with the microgrid-like operation and an additional current injection method.…”

“…The impact of intermittent renewable energy resources on the distribution network and the use of energy storage to mitigate this issue have been explored in Reference [12]. Authors in Reference [13] have analyzed the reliability and economic aspect of the microgrid with renewable energy resources and storage from the system planning perspective.Works in References [3,8,9,11,13] either only considers supply interruptions or the methods proposed are not readily applicable in the context of utility-scale distribution network. References [5][6][7]12] have taken into account the voltage sag/swell, however, generalized methods are lacking to incorporate the intermittency of renewable DGs and energy limitation of storages.…”