• Energy Research

This dataset contains time series data (time, power, current, voltage, temperature, grid frequency, SOC, status) of the field operation of a stationary large-scale battery storage system in the German power grid (frequency containment reserve and 15 min intraday trading). The dataset originates from the operation of the M5BAT (Modular Multi-Megawatt Multi-Technology Medium Voltage - Battery Storage System) battery storage system at RWTH Aachen University and is divided into 11 partial datasets. One partial dataset is included for each of the 10 battery units of the M5BAT large-scale battery storage system. One partial dataset is included for the entire system, which can be seen as a measurement at the grid connection point at 10 kV medium voltage. The file M5BAT_04-2023_RAW.zip contains the individual *.csv files with the time series data. The file Report_04-2023.pdf contains a description of the data, an evaluation of the data and the license.

Energy reports 13, 1029-1040 (2025). doi:10.1016/j.egyr.2024.12.057 Published by Elsevier, Amsterdam [u.a.]

The implementation of photovoltaic and home storage systems in multi-family houses (MFHs) in Germany lags significantly behind their development in single-family houses. The Landlord-to-Tenant (L2T) power supply model is meant to reduce this gap, yet few projects have been implemented to date. In this model, the landlord must fulfill the tenants’ power demand through a combination of photovoltaic generation and storage and electricity from the grid, for which the landlord pays an auxiliary electricity price that greatly influences the financial viability of a project. Our contribution focuses on the impact of electricity price variations and recent policy changes on the financial viability of small-scale L2T concepts. We considered component investment costs, building sizes, photovoltaic yields, and future developments. Recent policy changes have improved the financial viability of L2T projects, increasing the maximal auxiliary electricity price for which an investment is viable by 13 ct/kWh for a four-party MFH. Minimal auxiliary electricity prices justifying the installation of home storage systems (HSSs) decreased by 9 ct/kWh from 2020 to 2023. Autarky rates are substantially different across the considered scenarios, with the autarky rate being defined as the percentage of consumption of self-generated energy relative to the total energy consumption. For a 22-party MFH the autarky rate decreases by 17% compared to a 4-party MFH. HSSs have the potential to increase autarky rates while maintaining the financial viability of L2T projects.

Large-scale battery energy storage systems (BESS) already play a major role in ancillary service markets worldwide. Batteries are especially suitable for fast response times and thus focus on applications with relatively short reaction times. While existing markets mostly require reaction times of a couple of seconds, this will most likely change in the future. During the energy transition, many conventional power plants will fade out of the energy system. Thereby, the amount of rotating masses connected to the power grid will decrease, which means removing a component with quasi-instantaneous power supply to balance out frequency deviations the millisecond they occur. In general, batteries are capable of providing power just as fast but the real-world overall system response time of current BESS for future grid services has only little been studied so far. Thus, the response time of individual components such as the inverter and the interaction of the inverter and control components in the context of a BESS are not yet known. We address this issue by measurements of a 6 MW BESS's inverters for mode changes, inverter power gradients and measurements of the runtime of signals of the control system. The measurements have shown that in the analyzed BESS response times of 175 ms to 325 ms without the measurement feedback loop and 450 ms to 715 ms for the round trip with feedback measurements are possible with hardware that is about five years old. The results prove that even this older components can exceed the requirements from current standards. For even faster future grid services like synthetic inertia, hardware upgrades at the measurement device and the inverters may be necessary.

Large-scale stationary battery energy storage systems (BESS) continue to increase in number and size. Most systems have been put into operation for grid services because of their technical capabilities. With increasing and more dynamic energy prices, their use in short-term energy trading such as day-ahead and intraday trading has also been gaining importance. In current technical and economic simulations and trading models, batteries are often used as an energy reservoir that can charge and discharge a constant power specified by the energy over a certain time. However, this simplification can lead to wrong results and makes economic assessments difficult. In order to successfully use BESS in energy trading, their real operating ranges and limits must be investigated, since batteries respectively BESS cannot deliver the same power over the entire state of charge (SOC) range. With a performance test of our hybrid BESS M5BAT, we show the characteristic performance curves for different battery technologies and consequently suitable operating ranges in a large-scale system configuration. The results show the wide range of challenges such as battery aging and balancing states that occur in the real-world implementation of BESS. The lithium-ion batteries of the system under test have a remaining usable energy between 75 % and 90 %, depending on the type of lithium-ion battery, while the usable energy of the lead acid batteries is only 60 %. The lithium-ion batteries were able to deliver a constant power output in the SOC range between 10 % and 80 %, which is a necessary requirement in short-term energy trading. The lead-acid batteries could only be discharged at full power in the range of 100 %–50 % SOC and charged at full power between 0 % and 50 %. In the performance test, balancing was a limiting factor for lithium-ion batteries, while aging was the limiting factor for lead-acid batteries. Based on our findings, estimates for other existing BESS can be made to determine feasible operating ranges of these batteries for short-term energy trading. This also provides a guideline for individual tests that should be carried out on other BESS for verification. Applied energy 347, 121428 - (2023). doi:10.1016/j.apenergy.2023.121428 Published by Elsevier Science, Amsterdam [u.a.]

This data set contains the optimization results of the publication with title "Quantifying benefits of renewable investments for German residential Prosumers in times of volatile energy markets" (DOI: 10.1038/s41467-024-51967-6). It provides a wide range of optimized load profiles for German single-family houselhold Prosumers. For optimization, we use the FOCUS framework (https://doi.org/10.18154/RWTH-2023-04127) developed at RWTH Aachen University. Each Prosumer has a photovoltaic system and optionally a combination of battery home storage system and heat pump. We provide energy flows between all components as well as generation, demand, and all input data with a resolution of 15 minutes for one year. Further, the number of residents is varied from 1-6 and the year of construction of the building from 1979-2008. The dataset covers the years 2020, 2021, 2022, 2023, and 2030. For selected households we optionally consider variable electricity prices, price breaks for natural gas and electricicty as introduced during the energy crisis, a variation of the size of the photovoltaic system (8.7/13.7 kWp), households with an electric vehicle, and a variation of the interest rate for investments from 2-5%. In addition to energy flows, we share the underlaying linear programming LP pyomo model for each optimized household.