Estimation of Grid Reinforcement Costs Triggered by Future Grid Customers: Influence of the Quantification Method (Scaling vs. Large-Scale Simulation) and Coincidence Factors (Single vs. Multiple Application)

Bernd Thormann,Thomas Kienberger

doi:10.3390/en15041383

Abstract

The integration of future grid customers, e.g., electric vehicles, heat pumps, or photovoltaic modules, will challenge existing low-voltage power grids in the upcoming years. Hence, distribution system operators must quantify future grid reinforcement measures and resulting costs early. On this account, this work initially evaluates different methods to quantify future grid reinforcement needs, applied by the current state of research. Thereby, it indicates the significance of large-scale grid simulations, i.e., simulating several thousand low-voltage grids, to quantify grid reinforcements accurately. Otherwise, a selected area’s total grid reinforcement costs might be misjudged significantly. Due to its fast application, deterministic grid simulations based on coincidence factors are most commonly used in the current state of research to simulate several thousand grids. Hence, in the second step, recent studies’ approaches to applying grid customers’ coincidence factors are evaluated: While simplified approaches allow fast simulation of numerous grids, they underestimate potential grid congestion and grid reinforcement costs. Therefore, a fully automated large-scale grid simulation tool is developed in this work to allow the simulation of multiple grids applying grid customers’ coincidence factors appropriately. As a drawback, the applied deterministic framework only allows an estimation of future grid reinforcement costs. Detailed determination of each grid’s grid reinforcement costs requires time-resolved grid simulations.

Highlights

Carbon-neutrality has been declared a priority objective on both the European [1] and national level to mitigate global warming in the upcoming years
Total grid reinforcement costs determined by the analyzed quantification methods are illustrated as per unit values depending on the number of simulated grids (Figure 8): The simulation of one representative grid per grid region and the scaling of their results up to the total number of grids (Scaling of grid regions) reveals total grid reinforcement costs of 0.66 pu
This paper’s results identify the impact of LV grids’ heterogeneity on quantifying future grid reinforcement costs: Considering the analyzed grid area, simulating only a few individually selected grids and scaling their results leads to a broad spectrum of total grid reinforcement costs (Figure 8): If, for example, about 200 grids are selected for load flow simulation, the total costs might deviate between −66% and +82% from the actual value

Summary

Introduction

Carbon-neutrality has been declared a priority objective on both the European [1] and national level (e.g., in Austria [2]) to mitigate global warming in the upcoming years. The residential sector’s energy efficiency shall be increased, e.g., by implementing residential electric heat pumps (HPs) [1,3] While these transitions will reduce the traffic, energy, and residential sector’s carbon footprint, they require integrating numerous new grid customers into the existing power system. The majority (in number) of EVs, photovoltaic modules (PVMs), and electric HPs will be connected to the low-voltage (LV) level [4,5] As a result, these trends will unquestionably challenge existing LV grids in the following years [6,7,8]. Grid customers’ loads are implemented into grid models, modeled based on real-life grid topologies and data (e.g., line length and cross-section area) [14]

Methods

Results

Discussion

Conclusion