Power and Energy Quality Optimization of a Battery Validation Facility : A case study of mapping the power profile of a battery cell testing facility

Abstract: With Northvolt’s aggressive plan to establishEurope’s largest battery factory in northern Sweden, the needto build a pilot plant to demonstrate the possibilities of thecompany was needed. Quality, performance and cycle-life arekey factors customers value particularly high when purchasingbatteries, thus, a need for validating these parameters emerges.Performance and life-cycle tests are performed in high powerconsuming cycling units divided into the major components -chamber and cycler. The cycler is programmed according tospecific charge and discharge patterns (flows).A validation facility has been established close to NorthvoltLabs in V¨aster°as, housing cycling units for different cell formfactors. The major scope of this thesis was to find an optimalway to effectively and energy conscientious conduct operationsin the facility. One part included testing the possibility tore-utilize energy from discharging cells in simultaneouslycharging cells as well as testing if the equipment can provideenough energy to sell back to the electricity distributor.Additionally, an analysis to see if advanced planning can beused to balance the load profile of the validation facility andreduce energy costs was researched. A second part was todetermine if the equipment imposed harmonics on theconnected grid, and to decide if a filter is needed forPQ-compensation/harmonic filtering. Estimating the powerdemand of validation facility was needed to provide the gridowner an energy forecast. Firstly, to be able to analyze thesequestions, the power profile of the cycling units had to beestablished through measurements performed by installingpower quality devices. It was determined that the chambersconsumption was considerably higher than previously assumedand was in fact higher than the average charge-, anddischarge-flow performed by the cyclers. A power profile wasestablished for each type of cycling unit which was utilized in aMonte Carlo model to predict the power need of the facilitybased on new equipment arriving over the next couple of years.A basic energy cost return-of-investment-calculation concludedthat installing an high energy battery energy system was noteconomically feasible due to prevalent circumstances.