Impact of high penetration rates of home battery energy storage systems on low-voltage grid planning strategies

Abstract

Recently, home battery energy storage systems (BESSs) become increasingly economical for household applications. This study investigates the impact of various penetration rates of signal-based simultaneously charging BESS and varying modelling assumptions, e.g. for BESS simultaneous factors, on the low-voltage (LV) grid. The impact on the LV grid is quantified on the basis of line and transformer workloads a well as voltage deviations at the grid nodes. To this end, a case study is conducted with over 100 real LV grids in Northern Germany. The LV grids are analysed for multiple scenarios, using conventional grid planning tools and stationary power flow methods. A Monte Carlo simulation is applied with >100 varying BESS distribution settings per scenario. The results indicate that type and location of limit violations in the LV grid are predictable and therefore to be integrated with grid-planning strategies. Under the assumptions made, the transformer is particularly prone to limit violations starting at penetration rates of 5%. The share of overloaded power lines remains below 6%. Here, certain bottlenecks occur, e.g. main supply lines to the transformer. The great variance between the share of violated nodes of individual grids points out a high sensitivity to local network infrastructure conditions.